Diesel exhaust exposure intensifies inflammatory and structural changes associated with lung aging in mice Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-07 Gabriel Ribeiro Júnior, Natália de Souza Xavier Costa, Luciano Belotti, Adair Aparecida dos Santos Alemany, Luís Fernando Amato-Lourenço, Paula Gabriela da Cunha, Stephanie de Oliveira Duro, Susan Pereira Ribeiro, Mariana Matera Veras, Fernanda Degobbi Tenorio Quirino dos Santos Lopes, Tania Marcourakis, Paulo Hilário Nascimento Saldiva, Sandra Helena Poliselli Farsky, Thais Mauad
Life expectancy is increasing worldwide. Lung aging is a process marked by changes in multiple morphological, physiological and age-related biomarkers (e.g., sirtuins) and is influenced by external factors, such as air pollution. Hence, the elderly are considered more vulnerable to the air pollution hazards. We hypothesized that diesel exhaust (DE) exposure intensifies changes in lung inflammatory and structural parameters in aging subjects. Two- and fifteen-month-old mice were exposed to DE for 30 days. Lung function was measured using the forced oscillation method. The inflammatory profile was evaluated in the bronchoalveolar lavage fluid (BALF) and blood, and lung volumes were estimated by stereology. Antioxidant enzyme activity was evaluated by spectrophotometry, sirtuin 1 (SIRT1), sirtuin 2 (SIRT2) and sirtuin 6 (SIRT6) expression was assessed by reverse transcription polymerase chain reaction (RT-PCR), and levels of the sirtuin proteins were evaluated by immunohistochemical staining in lung tissues. Older mice presented decreased pulmonary resistance and elastance, increased macrophage infiltration and decreased tumor necrosis factor (TNF) and interleukin 10 (IL-10) levels in the BALF, reduced activities of the antioxidant enzymes glutathione peroxidase (GPx) and glutathione reductase (GR), and increased activity glutathione S-transferase (GST); increased lung volumes with decreased elastic fiber and increased airway collagen content. SIRT1 gene expression was decreased in older animals, but protein levels were increased. DE exposure increased macrophage infiltration and oxidative stress in the lungs of animals of both ages. SIRT6 gene expression was decreased by DE exposure, with increased protein levels. In older animals, DE affected lung structure and collagen content. Lung aging features, such as decreased antioxidant reserves, lower IL-10 expression, and decreased SIRT1 levels may predispose subjects to exacerbated responses after DE exposure. Our data support the hypothesis that strategies designed to reduce ambient air pollution are an important step towards healthy aging.
Novel brominated flame retardant (NBFR) concentrations and spatial distributions in global fishmeal Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-07 Xiaomin Li, Shujun Dong, Ruiguo Wang, Peilong Wang, Zheng Ruan, Xiaoming Sun, Qinxiong Rao, Zehui Liu, Xiaoou Su
Novel brominated flame retardants (NBFRs), which are lipophilic compounds that have been widely applied after the phasing-out of legacy BFRs, can bioaccumulate through the food chain. However, information on NBFRs in animal feeds, the beginning of farm-to-fork pathway, is very limited. Fishmeal is one of the most widely applied feedstuff worldwide. The present study identified eleven NBFRs from ninety-two globally collected fishmeal samples with levels in the range of 0.13–822 (mean: 15.1 ± 85.5) ng/g lipid weight (lw). Hexabromobenzene (HBB) and pentabromotoluene (PBT) were the most prevalent contributors (detection frequencies: 95.7% and 73.9%, respectively), and decabromodiphenylethane (DBDPE) was the weightiest contributor (accounted for 67.1% of the ΣNBFRs, mean: 12.1 ± 84.8 ng/g lw). From a geographical view, the highest NBFR level was found in Chinese fishmeal. The NBFRs fell within an order of magnitude in South America, Southeast Asia, Europe and United States. DBDPE was predominant in the fishmeal collected from China, South America and United States, but it was not detected in European fishmeal. The NBFR levels are significantly lower compared to the polybrominated diphenyl ethers (PBDEs) (p < 0.01), indicating that the distribution of NBFRs was not as wide as PBDEs in fishmeal. DBDPE was significantly correlated with BDE209 (r = 0.557, p < 0.01), which implies that the two chemicals might have similar sources. Quantitative structure-activity relationship (QSAR)results imply that the NBFRs might have similar persistence and biomagnification potential as legacy lipophilic POPs.
Acute effect of ambient air pollution on hospitalization in patients with hypertension: A time-series study in Shijiazhuang, China Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-07 Jie Song, Mengxue Lu, Jianguo Lu, Ling Chao, Zhen An, Yue Liu, Dongqun Xu, Weidong Wu
Although numerous studies have investigated the association between air pollution and hospitalization, few studies have focused on the health effect of air pollution on populations with hypertension. In this study, we conducted a time-series study to investigate the acute adverse effect of six criteria ambient air pollutants (fine particulate matter [PM2.5], inhalable particulate matter [PM10], nitrogen dioxide [NO2], sulfur dioxide [SO2], ozone [O3], and carbon monoxide [CO]) on hospitalization of patients for hypertension in Shijiazhuang, China, from 2013 to 2016. An over-dispersed Poisson generalized addictive model adjusting for weather conditions, day of the week, and long-term and seasonal trends was used. In addition, we evaluated the effect of modification by season, sex, and age. A total of 650,550 hospitalization records were retrieved during the study period. A 10 μg/m3 increase of PM2.5 (lag06), PM10 (lag06), NO2 (lag03), O3 (lag6), and CO (lag04) corresponded to 0.56% (95% confidence interval [CI]: 0.28–0.83%), 0.31% (95% CI: 0.12–0.50%), 1.18% (95% CI: 0.49–1.87%), 0.40% (95% CI: 0.09–0.71%), and 0.03% (95% CI: 0.01–0.05%) increments in hospitalization of patients for hypertension, respectively. We observed statistically significant associations with PM2.5, PM10, NO2, O3, and CO, while positive but insignificant associations with SO2. The effects of PM2.5, PM10, NO2, O3, and CO were robust when adjusted for co-pollutants. We found stronger associations in the cool season than in the warm season. Moreover, there were non-significant differences in the associations between air pollution and sex or age group. This study suggests that patients with hypertension had an increased risk of hospital admission when exposed to air pollution.
Rate constants for the reaction of hydroxyl and sulfate radicals with organophosphorus esters (OPEs) determined by competition method Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-07 Ting Tang, Guining Lu, Rui Wang, Zhiyuan Qiu, Kaibo Huang, Wenjie Lian, Xueqin Tao, Zhi Dang, Hua Yin
Advanced oxidation processes (AOPs), such as hydroxyl radical (•OH) and sulfate radical (•SO4-) mediated oxidation, are proved to be effective methods to remove the organophosphorus esters (OPEs) in wastewater effluents. However, few studies have reported about the bimolecular reaction rate constants between free radicals (•OH and •SO4-) and OPEs. This issue was solved by selecting three OPEs as model compounds, the oxidation of these OPEs in UV/H2O2 and UV/K2S2O8 process were studied. Tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(2,3-dichloropropyl) phosphate (TDCPP) can hardly be oxidized through direct irradiation methods using UV lamp, with the oxidation rate less than 30% after 7 h′ irradiation. However, TCEP, TCPP, and TDCPP undergo degradation via UV/H2O2 and UV/K2S2O8 processes easily, the oxidation rates increased with increasing H2O2 and K2S2O8 dosage. The oxidation rates of three OPEs have been studied using competition experiments in the UV/H2O2 and UV/K2S2O8 processes. The bimolecular reaction rate constants of TCEP, TCPP and TDCPP with •OH were 2.50 × 1010, 3.95 × 1010 and 2.94 × 1010 respectively; while •SO4- were 3.00 × 107, 1.82 × 107 and 2.06 × 107 respectively. Results showed that the simplified kinetic model involves only steady state concentration of free radicals and the molecular reaction rate contents are available for calculating the oxidation rates of OPEs in ultrapure water.
Biodegradation patterns of the endocrine disrupting pollutant di(2-ethyl hexyl) phthalate by Fusarium culmorum Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-07 Angel González-Márquez, Octavio Loera-Corral, Ericka Santacruz-Juárez, Saúl Tlécuitl-Beristain, Jorge García-Dávila, Gustavo Viniegra-González, Carmen Sánchez
Di(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer, which is considered an endocrine disrupting pollutant. Growth kinetics and esterases activity by biochemical tests and polyacrylamide gel electrophoresis were characterized for Fusarium culmorum grown in DEHP-supplemented (1000 mg/L) medium as the only carbon source and in control medium with glucose. Intermediate compounds of biodegraded DEHP were identified by GC-MS. F. culmorum degraded 92% of DEHP within 36 h. DEHP was degraded to butanol, hexanal, catechol and acetic acid. It is suggested that the first two compounds would transform into butanediol and the last two would enter into the Krebs cycle and would be mineralized to CO2 and H2O. DEHP induced eight esterase isoforms, which were different to those constitutive isoforms produced in the control medium. It is suggested that five enzymes (25.7, 29.5, 31.8, 97.6 and 144.5 kDa) detected during the first 36 h be involved in the primary biodegradation of DEHP. The rest of the enzymes (45.9, 66.6 and 202.9 kDa) might be involved in the final steps for DEHP metabolism. F. culmorum has a promising practical application in the treatment of DEHP-contaminated environments because it can secrete specific esterase to breakdown high concentrations of DEHP in a short period of time. This research represents the first approach for the study of esterase involved in the DEHP degradation by fungi using this phthalate as the sole source of carbon and energy.
Adsorptive removal of bisphenol A, chloroxylenol, and carbamazepine from water using a novel β-cyclodextrin polymer Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-07 Yanbo Zhou, Guang Cheng, Ke Chen, Jian Lu, Juying Lei, Shengyan Pu
The emerging organic micro-pollutants, such as bisphenol A (BPA), chloroxylenol (PCMX) and carbamazepine (CBZ), have raised concerns owing to their adverse impact on human health and ecological security. In this study, a novel cyclodextrin polymer (β-CDP) has been successfully prepared by nucleophilic substitution of β-cyclodextrin with tetrafluoroterephthalonitrile (TFP). The removal of three emerging organic micro-pollutants (BPA, CBZ and PCMX) by β-CDP under a single or mixture adsorption system was examined, and the adsorption behavior was investigated by adsorption kinetics and isotherm study. The maximum adsorption capacity of β-CDP for BPA, PCMX and CBZ according to Langmuir isotherm in single system was 164.4, 144.1 and 136.4 mg/g, respectively. Compared with single system, the competitive adsorption of each pollutant on β-CDP in mixture system was only slightly inhibited. Changing the pH, raising the presence of fulvic acid (FA) or ionic strength had no significant influence on the adsorption of BPA, PCMX and CBZ onto β-CDP. The removal of these three organic micro-pollutants was related to the value of logKow of the contaminants. These results demonstrated remarkable advantages of β-CDP material relevant to organic micro-pollutants removal in wastewater treatment.
Exploring the survival tactics and plant growth promising traits of root-associated bacterial strains under Cd and Pb stress: A modelling based approach Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Shatrohan Lal, Rajesh Kumar, Shamshad Ahmad, Vijay Kant Dixit, Graziella Berta
The study represents a microbial method for reducing heavy metal stress in terrestrial environment. Two rhizobacterial strains Pantoea agglomerance (PC1) and Pseudomonas aeruginosa (SA) having the ability to tolerate Cd2+ and Pb2+ ions stress, were employed in this study. The growth promotion and survival tactics of the strains under metal stress were explored through kinetic growth model using logistic equation, Luedeking-Piret model and Box Behnken design. Study also involves the interaction of strains with Zea mays L. under Cd2+ and Pb2+ ions stress. Results revealed that both strains have the potential to tolerate 500 mg L−1 of Cd2+ and Pb2+, ions and maintained the plant growth promoting traits. The Luedeking-Piret model estimated the maximum value of IAA on biomass growth (YP/X) 5.377 μg g−1 and 10.3 μg g−1 under Cd2+ ions, while 7.742 μg g−1 and 18.071 μg g−1 under Pb2+ ions stress for strains SA and PC1, respectively. Further, phosphate solubilization activity was optimized with the help of response surface methodology using Box Behnken Design. The optimum solubilization by strain PC1 and SA was achieved at 100 and 150 mg L−1 of Cd2+, and 150 and 200 mg L−1 of Pb2+ ion concentration at the pH range 6.75 and 7.5 respectively. The interactive study with Zea mays L. showed significant increase in seed germination in the presence of Cd2+ and Pb2+ ions thereby proving them as potent plant growth promoters and metal stress reducing biological agents. Hence, the findings of the study suggest that rhizobacterial strains could be a sustainable tool for restoration of metal contaminated sites.
Maternal exposure to fine particulate matter and the risk of fetal distress Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Hongxiu Liu, Jiaqiang Liao, Yangqian Jiang, Bin Zhang, Huifang Yu, Jiawei Kang, Cheng Hu, Yuanyuan Li, Shunqing Xu
Prenatal life exposure to fine particulate matter (aerodynamic diameter less than or equal to 2.5 µm, PM2.5) has been linked with increased risk of adverse fetal development and birth outcomes in previous studies. However, to our knowledge, no study has investigated the association of maternal PM2.5 with the risk of fetal distress, which is a harmful fetal status and may lead to fetal brain damage, even fetal death. Therefore, we conducted a study to determine the association between maternal PM2.5 and fetal distress among 7835 mother-infant pairs from a birth cohort, in Wuhan, China, 2013–2015. The individual daily PM2.5 level was assessed using land use regression model. We evaluated the association of maternal PM2.5 level over the whole pregnancy with fetal distress by logistic regression model, and estimated the risk between PM2.5 exposure in specific trimester and fetal distress using generalized estimating equations. We observed that per 10 µg/m3 change of maternal PM2.5 level over the whole pregnancy was associated with 25% increased risk of fetal distress (95% confidence interval: 1.09–1.44). Further, we found PM2.5 level in the 2nd trimester, but not in the 1st and 3rd trimesters, was associated with fetal distress. Stratified analyses indicated that the association was only significant among infants who were born in cold seasons. Our study suggested that PM2.5 exposure during the whole pregnancy exhibited significant associations with the risk of fetal distress, and exposure in the 2nd trimester maybe the susceptible window. Further stratified analyses indicated that birth season is a possible modifier in the association.
Source apportionment of selenium and influence factors on its bioavailability in intensively managed greenhouse soil: A case study in the east bank of the Dianchi Lake, China Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Mengmeng Jia, Yanxia Zhang, Biao Huang, Haidong Zhang
Selenium (Se) is an essential trace element for humans and animals. In China, intensive agricultural inputs in greenhouse vegetable production (GVP) have resulted in great changes in Se concentration and bioavailability in soil, which have great influences on Se flux to living organisms through food chains. It is crucial to understand the factors on Se concentration and bioavailability in greenhouse soil. Thus, we chose the east bank of the Dianchi Lake, a typical GVP area covering 177 km2 in Southwest China, as the study area to quantify source contributions to soil Se and estimate relative importance of influence factors on its bioavailability in GVP with a receptor model (absolute principal component scores-multiple linear regression, APCS-MLR) after principal component analysis (PCA). According to the enrichment factor (EF), total Se in greenhouse soil was accumulated at a minor level (1 < EF < 3) by long-term and intensive fertilization. Source contributions to total Se decreased in the sequence of parent materials > fertilization > atmospheric deposition. It suggested that fertilization, especially manure, might be an important way to increase total Se in greenhouse soils in Se-deficient areas. The bioavailability of Se was affected by several factors, among of which total Se was the foremost one. In comparison with organic matter and clay, Fe/Al oxides exerted more controls on Se bioavailability, which was dependent on pH. Increasing Olsen P was helpful in improving soil Se bioavailability in greenhouse. More attention should be paid to soil physicochemical characteristics when Se-containing fertilizers are applied to increase Se levels in greenhouse vegetables.
Oxidative degradation of chlorpyrifos using ferrate(VI): Kinetics and reaction mechanism Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Hongxia Liu, Jing Chen, Nannan Wu, Xinxin Xu, Yumeng Qi., Lijuan Jiang, Xinghao Wang, Zunyao Wang
In this study, we investigated the degradation kinetics of chlorpyrifos, an organophosphorus (OP) compound, using ferrate(VI), and investigated the potential of this iron-based chemical oxidant on chlorpyrifos removal from water and wastewater treatments. A series of kinetic experiments were conducted to evaluate the influence of various environmental factors, such as pH, oxidant dosages, as well as the presence of anions, cations, humic acid (HA), and different water matrices. Chlorpyrifos was completely removed within 300 s under the following optimum conditions: [chlorpyrifos]0 = 1 μM, [Fe(VI)]0:[chlorpyrifos]0 = 100:1, T = 25 °C, and pH = 7.0. Anions such as Cl−, SO42−, NO3−, and HCO3− and cations such as Fe3+, Cu2+, and NH4+ did not appear to influence the removal of chlorpyrifos. However, the presence of Ca2+, Mg2+, and HA in water inhibited the degradation of chlorpyrifos. Experiments on removing chlorpyrifos from tap water, river water, and synthetic wastewater were performed to demonstrate the practical applications of Fe(VI). Ten oxidation products of chlorpyrifos were identified using liquid chromatography-quadrupole-time-of flight-mass spectrometry (LC-Q-TOF-MS), and their structures were further elucidated using MS/MS spectra. Then, two degradation pathways were preliminarily proposed including the oxidation of the P = S bond, cleavage of C–O bond, and hydroxyl substitution reaction. In general, Fe(VI) could be used as an efficient technology for chlorpyrifos removal from water and wastewater treatments.
Study on the influence of soil microbial community on the long-term heavy metal pollution of different land use types and depth layers in mine Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Xingqing Zhao, Jian Huang, Jin Lu, Yu Sun
To understand the importance of the response of soil microbial communities to the stress of heavy metals around mining areas by assessing the feedback of soil ecosystems in different soil habitats, this article selected different land use types (Mining area, Dressing area, Heap mine area, Tailings area and Vegetable field) and surface soil samples of different depths (0–10 cm, 10–20 cm, 20–30 cm) as the variables related to the mining activities in the Shizishan mining area in Tongling, Anhui Province, China. Soil physicochemical properties and heavy metal concentrations of the different land use types and soil depths were compared. Illumina MiSeq. 2500 Sequencing Technology was used to analyze the abundance and structural diversity of the microbial community in soil samples. The relationship between mine soil pollution characteristics and microbial community were investigated. The results showed that soil physicochemical properties and heavy metals significantly affected the microbial community. The microbial community structure was significantly variable in vertical soil depth-layer habitats. The relative abundance (1%) of the soil microbial community at the phylum level was represented by a total of 14 phyla, where the two most dominant phyla were Proteobacteria (41.71%) and Firmicutes (20.44%). The two bacteria were positively related with Cu, Zn, Pb, and pH but negatively associated with soil organic matter (SOM), available potassium (AK), and moisture content (MC). Therefore, Proteobacteria and Firmicutes were highly resistant to heavy metals. These results increased our understanding of microbial variation and assembly pattern under different land use types in heavy metals contaminated mining soils.
Combined nitrogen fertilizer and wheat straw increases the cadmium phytoextraction efficiency of Tagetes patula Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Xinxin Ye, Hongxiang Hu, Hongying Li, Qizhong Xiong, Hongjian Gao
The soil cadmium (Cd) availability and uptake by Tagetes patula grown in two soil types contaminated with Cd and amended with N fertilizer and wheat straw were studied in a pot-culture experiment. The results indicated that N fertilizer treatment (N) and N fertilizer plus straw treatment (NS) promoted T. patula growth, while straw treatment (S) decreased T. patula biomass relative to the control. NS and S treatments increased Cd mobility in the soil and facilitated its uptake by T. patula in Acidic Ferralsols (AF) and Calcaric Cambisols (CC), but the promotion effect was much greater in CC than in AF. The Cd concentrations in the Tagetes shoots in the S and NS treatments were 40% and 27% greater, respectively, than those in the control treatment for AF, and 111% and 80% greater, respectively, for CC. Decreases in soil pH and increases in dissoluble organic carbon concentration after adding N fertilizer and straw were associated with an increase in soil Cd availability and in Cd uptake by T. patula. The results indicate that the NS treatment can alter the soil microenvironment, increasing Cd bioavailability and thus facilitating Cd uptake by T. patula. This work highlights that the combined application of N fertilizer with straw may be a useful way to increase the phytoextraction efficiency of Cd-contaminated soil by the Cd-hyperaccumulator T. patula.
Immobilized bacterial biosensor for rapid and effective monitoring of acute toxicity in water Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Hendri Wasito, Amin Fatoni, Dadan Hermawan, Sri Sutji Susilowati
The use of biosensors by using microorganisms such as bacteria have short life cycles and provide other advantages. One colorimetric biosensor technique that has been developed is the use of a biosensor utilizing the incorporation of Prussian blue formation reactions mediated by E. coli bioreactors with ferricyanide. Immobilization is a method that allows the bacteria can be used for long-term without reducing its ability as bioreceptor. This study aimed to develop a novel and rapid immobilized bacterial biosensor for the detection of toxic compound in water and to evaluate their analytical performances. Immobilization of E. coli performed by trapping method using alginate material support. The bacterial suspension was mixed with sodium alginate (1:1 v/v), and the mixture was continuously dropped in CaCl2 solution to be a form of beads. The beads were used as bioreceptor to detect toxicants regarding cadmium, arsenic, mercury, chromium and lead solutions with Prussian blue as a colorimetric indicator. The linearity and sensitivity of detection of beads to the toxicants were tested, the stability of repeated use and storage were evaluated as well. The results showed that E. coli could be immobilized using alginate with response value was correlated with toxic concentration. The developed biosensor was more stable when used repeatedly and could be stored in a long time. The immobilization of E. coli in calcium alginate bead was successfully performed as a biosensor system for monitoring acute toxicity in water.
Potential ability for metallothionein and vitamin E protection against cadmium immunotoxicity in head kidney and spleen of grass carp (Ctenopharyngodon idellus) Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Xiaoli Huang, Yang Feng, Wei Fan, Jing Duan, Yajiao Duan, Guanqing Xiong, Kaiyu Wang, Yongqiang Deng, Yi Geng, Ping Ouyang, Defang Chen, Shiyong Yang
Cadmium (Cd) pollution is an important issue affecting the food safety of aquatic products. Cd can impair the immune system and cause irreversible damage to fish and other aquatic organisms. The immunoprotection activities of exogenous metallothionein (MT) and vitamin E (VE) were investigated in Cd poisoned grass carp, Ctenopharyngodon idellus, in the present study. C. idellus were divided into three groups: Cd+phosphate-buffered saline (PBS) group; Cd+MT; and Cd+VE. All fish were injected with cadmium chloride (CdCl2) on the first day and then treated with PBS, MT or VE four days post-injection. Fish not injected with Cd were used as a negative control. Cd exposure caused severe head-kidney and splenic injury in C. idellus, mainly expressed as an increase in Cd content, histological damage, percentage of head-kidney and splenic cells apoptosis and decreases in immune-related gene mRNA transcript expression. However, MT and VE treatments protected against Cd-induced immunotoxicity in C. idellus by decreasing Cd contents, lessening histological damage, reducing the percentage of apoptosis and recovering immune-related mRNA transcript expression. Our results demonstrate that MT and VE can alleviate Cd-induced immunotoxicity and that MT has a more powerful effect than VE, indicating that MT could be a potential antidote in cases of Cd poisoning.
Developmental neurotoxicity of maneb: Notochord defects, mitochondrial dysfunction and hypoactivity in zebrafish (Danio rerio) embryos and larvae Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-06 Fangjie Cao, Christopher L. Souders, Pengfei Li, Sen Pang, Xuefang Liang, Lihong Qiu, Christopher J. Martyniuk
Broad applications and exposure to the fungicide maneb can lead to toxicity in non-target organisms. Maneb is also associated with neurogenerative diseases such as Parkinson's disease (PD). The objectives of this study were to determine the acute toxicity of maneb to zebrafish by measuring mitochondrial bioenergetics, locomotor activity, and the expression of genes related to the oxidative damage response, as well as those related to dopamine signaling due to its association with PD. Zebrafish embryos at 6 h post-fertilization (hpf) were exposed to either solvent control (0.1% DMSO, v/v), or one dose of 0.1, 0.5, 1.0 and 10.0 µM maneb for 96 h. Maneb was moderately toxic to zebrafish embryos, and had a 96-h LC50 value of 4.29 μM (~ 1.14 mg/L). Maneb induced a dose-dependent increase in mortality, decreased hatching rate, and increased notochord deformity rate at both 1.0 and 10.0 µM after 72 and 96 h. Total body length was also significantly reduced with 1.0 µM maneb. A 50–60% decrease in mean basal oxygen consumption rate was also observed in embryos following a 24 hpf exposure to 10.0 µM maneb but oligomycin-induced ATP production and FCCP-induced maximum respiration remained unaffected. No change was detected in the expression levels of genes associated with oxidative stress (sod1 and sod2), nor those related to dopamine synthesis (th1), dopamine transporter (dat), dopamine receptors (drd1, drd2a, drd3, and drd4b). Thus, modifying the expression of these transcripts may not be a mechanism for maneb-induced developmental toxicity in zebrafish. To assess the potential for neurotoxicity, a dark photokinesis assay was conducted in larvae following 7 d exposure to 0.1, 0.5 and 1.0 μM maneb. Larvae exposed to 0.5 and 1.0 μM maneb showed signs related to hypoactivity, and this reduced activity is hypothesized to be associated with notochord defects as this deformity was prevalent at higher concentrations of maneb. Overall, these data demonstrate that maneb negatively affects embryonic development (i.e. notochord development), affects basal oxygen consumption rates of embryos, and induces hypoactivity in larval fish. This study improves understanding regarding the developmental neurotoxicity of the fungicide maneb to zebrafish.
Insight into occurrence, profile and spatial distribution of organochlorine pesticides in soils of solid waste dumping sites of Pakistan: Influence of soil properties and implications for environmental fate Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Marriya Sultan, Sidra Waheed, Usman Ali, Andrew James Sweetman, Kevin C. Jones, Riffat Naseem Malik
Waste dumping sites are considered as significant disposal pathway for waste contaminants including pesticides. In the present study OCPs were analyzed in soils of waste dumping sites of Pakistan. The mean concentrations of OCPs were in the order: ∑DDTs>∑HCHs>∑Endosulfan>∑HCB>Heptachlor. Order of overall ∑OCPs contamination with respect to location was Lahore>Sukkur>Karachi>Kamoki>Faisalabad>Hyderabad>Losar>Gujrat>Peshawar. Distribution of OCPs in solid waste dumping site was mainly influenced by textural classes, input history and pollution source. Soil texture was the dominant factor for retention of OCPs, whereas TOC and black carbon has not significantly impacted the concentrations of OCPs. Diagnostic ratios indicated the historical input, anaerobic degradation pathway and use of technical mixtures of DDTs in majority of waste dumping sites whereas for HCHs recent as well as past usage of technical mixture was prevalent in most of the areas. Regression analysis revealed a weak positive correlation of OCPs with socioeconomic indices (HDI, Population, waste generation) which is linked with history of use of these contaminants in the respective areas. Forecasted waste generation quantity for the year 2026 showed that waste generation amount will get doubled by the year 2026 suggesting the need properly designed waste management system.
MAPK/AP-1 pathway activation mediates AT1R upregulation and vascular endothelial cells dysfunction under PM2.5 exposure Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Xiuduan Xu, Huan Xu, Aodeng qimuge, Shasha Liu, Hongli Wang, Meiru Hu, Lun Song
Acute and chronic exposure to particulate matter (PM) 2.5 is associated with adverse health effect upon the cardiovascular (CV) system. However, the molecular mechanism by which PM2.5 evokes CV injuries has not been fully clarified. In our recent report, we demonstrate that exposure to PM2.5 leads to elevation of circulating angiotensin II (ANGII) levels and local expressions of angiotensinogen (AGT, the precursor of ANGII), angiotensin-converting enzyme (ACE) and ANGII type 1 receptor (AT1R) in the vascular endothelial cells, which subsequently instigates the oxidative stress and proinflammatory response in the vascular endothelium. In the present study, we disclosed that PM2.5 exposure induced the activation of the transcriptional factor AP-1 and its components, c-Jun and ATF2, in the human vascular endothelial cells. Although the DNA-binding sites for AP-1 were identified within the promoter regions of AGT, ACE and AT1R genes, RT-PCR and immunoblot assays indicated that AP-1 transactivation was only involved in AT1R upregulation, but did not affect the induction of AGT and ACE expression under the same conditions. Furthermore, ERKs and p38K functioned as the upstream protein kinases involving in AP-1 transactivation and AT1R upregulation under PM2.5 stimulation. In addition, the oxidative stress and proinflammatory responses in the PM2.5-treated vascular endothelial cells were significantly reduced when MAPKs and AP-1 activation were inhibited. Therefore, we conclude that PM2.5 exposure induces MAPK/AP-1 cascade activation, which contributes to AT1R upregulation and vascular endothelial dysfunction. Identifying novel therapeutic targets to alleviate AP-1 transactivation and restore AT1R expression may be helpful for the management of PM2.5-induced CV burden.
Microplastic abundance, distribution and composition in water, sediments, and wild fish from Poyang Lake, China Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Wenke Yuan, Xiaoning Liu, Wenfeng Wang, Mingxiao Di, Jun Wang
Microplastic pollution in global aquatic environments has aroused increasing concern in recent years. In this study, the occurrence of microplastics in multiple environmental compartments was investigated in Poyang Lake, the largest freshwater lake of China. The abundance of microplastics was respectively 5–34 items/L for surface waters, 54–506 items/kg for sediments, and 0–18 items per individual for wild crucians (Carassius auratus). The distribution of microplastics in Poyang Lake varied heterogeneously in space, with the highest abundance being observed in the middle region of the lake for surface waters and in the northern region for sediments. Anthropogenic and topographic factors were speculated to be the major factors affecting the abundance and distribution of microplastics. The majority of the detected microplastics were found with a size of < 0.5 mm, with fibrous and coloured being the predominant characteristics. Polypropylene (PP) and polyethylene (PE) were the major polymer types of the selected plastic particles, indicating that domestic sewage and fishing activities might be the main sources of microplastics in the lake. No significant correlation was observed between microplastic abundance in surface water and sediment samples. Our results demonstrated the wide occurrence of microplastics in water, sediment and biota of the Poyang Lake, which may assist in extending our knowledge regarding microplastics pollution in inland freshwater systems.
Pollution characteristics of metal pollutants in PM2.5 and comparison of risk on human health in heating and non-heating seasons in Baoding, China Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Bolong Liang, Xi-liang Li, Ke Ma, Shu-xuan Liang
PM2.5 particles were collected to study the distribution, accumulation and health risk assessment of metal pollutants. The concentrations of 11 kinds of metal elements in PM2.5 during heating period and non-heating period were analyzed. Based on the American health risk assessment model as well as the human exposure parameters in China, the human health risk was assessed. The concentrations of metal components in PM2.5 during the heating period were, in descending order, Pb, Mn, Cr, As, Sb, Se, Ni, Cd, Tl, Hg, and Be, while during the non-heating period, they were basically in the same order, except Cd and Ni, as the concentration of the former was a little higher than that of the latter. The concentrations of As, Cd, Hg, Ni, Se, and Tl were quite different in the heating period and non-heating period. The non-carcinogenic risks caused by metal elements were lower than the minimum acceptance 10−6 per year during both the heating period and non-heating period. The non-carcinogenic results of a descending order were Pb, Mn, Sb, Tl, Se, and Hg. The carcinogenic risks of a descending order were Cr, As, Cd, Ni, and Be. The risks of As and Cr to children were over 10−6. Hence, As and Cr should be considered as priorities.
Assessment of potentially toxic trace element contamination in urban allotment soils and their uptake by onions: A preliminary case study from Sheffield, England Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Annika M. Weber, Tinashe Mawodza, Binoy Sarkar, Manoj Menon
Toxic trace element (TTE) contamination in urban soils may pose potential health risks, especially in cities with previous industrial activities. This study aimed to investigate soil contamination in urban allotments in Sheffield, the uptake of TTEs in autumn and spring sown onions (Allium cepa), and their potential risks on human health via consumption of the crops. Paired soil and plant samples were taken in triplicates from four private allotments to assess potentially elevated levels of lead (Pb), zinc (Zn), copper (Cu), arsenic (As), and chromium (Cr). These elements in soils exceeded the ambient background levels for England. Both Pb and As exceeded some UK and EU soil tolerable limits. Concentration factors (CF) were calculated as the ratio of trace element in the plant as compared to that in the soil, and uptake rates were in the order Zn>Cu>Cr>Pb>As. Concentrations were higher for most TTEs in spring sown onions (SSO), and had significantly higher CF (p < 0.05) for Pb and Cr than autumn sown onions (ASO), whereas the opposite was true for As. Toxic elements in plants did not exceed FAO/WHO intake limits when considering TTE content per plant and consumption rates. Human health risk assessment calculations using target hazard quotients (THQ) and hazard indexes (HI) indicated that consuming onions alone did not pose an immediate health risk.
Analysis of polyhalogenated carbazoles in sediment using liquid chromatography–tandem mass spectrometry Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Wenxiu Zhou, Xinwen Huang, Kunde Lin
The purpose of this study was to develop a novel and sensitive method for the analysis of carbazole and polyhalogenated carbazoles (PHCs) in sediment using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Briefly, 5.0 g of freeze-dried sediment samples were extracted with dichloromethane using pressurized liquid extraction (PLE). The extract was purified with Florisil solid phase extraction cartridge, filtered through 0.22 µm polytetrafluoroethylene filter using a glass syringe, followed by LC-MS/MS analysis. Besides parameters for LC-MS/MS analysis, sample preparation procedures (including solvents for PLE, sorbents for cleanup, and filters for sample filtration) were optimized. The limits of detection and limits of quantification of target compounds were in the ranges of 3.0 × 10−3 to 0.22 ng g−1 dry weight (d.w.) and 1.0 × 10−2 to 0.75 ng g−1 d.w., respectively. The recoveries of target compounds in the spiked sediments at 2.0 ng g−1 d.w. and 10 ng g−1 d.w. were 64.8–91.8% and 70.9–124.7%, respectively, with relative standard deviations being less than 13.2%. Except that 36-BCZ had positive matrix effects of 63.3%, the sediment matrices generally displayed low or medium negative matrix effects on the other target compounds during LC-MS/MS analysis. The developed method was applied in the analysis of carbazoles and PHCs in sediment samples from Jiulong River, Fujian, China and all the target compounds were detected in the samples.
Using Nrf2/antioxidant response element-dependent signaling to assess the toxicity potential of fly ash particles Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Hongyan Wang, Yiping Chen, Jingwen Zhang, Xiuwen Tang, Xiu Jun Wang
Epidemiological studies have demonstrated an association between ambient particulate pollution and adverse health effects in humans. The antioxidant-responsive element (ARE) cytoprotective system mediated by the transcription factor NF-E2 p45-related factor 2 (Nrf2) serves as a primary defense against the oxidative stress triggered by particulate matter. In this study, using a cell-based ARE-reporter assay, the fine fractions of the fly ash collected from the municipal solid waste incinerators at four cities in China were examined for their ability to activate Nrf2/ARE signaling. We found that, at a non-lethal dose, all the fly ash samples were able to activate the ARE-reporter gene in a dose- and redox-dependent manner, and this was correlated with their cytotoxicity and their ability to induce DNA damage. Study of the kinetics revealed that fly ash particles elicited a prolonged activation of the ARE-reporter activity. Upon exposure to the particles, the ARE-luciferase activity significantly increased in 2 h, reached a peak at 24 h, and remained high level at 72 h. This was in contrast to the transient activation of the ARE-reporter gene triggered by the Nrf2 activators tert-butylhydroquinone and sulforaphane, while ARE-luciferase activity dropped to the basal level at 72 h from the peak at 24 h. These results demonstrate the robustness of using cell-based ARE-reporter assays to evaluate the oxidative potential of fly ash. Our novel findings suggest that the sustained activation of the Nrf2/ARE signaling pathway induced by fly ash particles perturbs cellular redox homeostasis, which in turn contributes to toxicity.
Cardiotoxicity of Consolida rugulosa, a poisonous weed in Western China Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Liang Lei, Weiguang Sun, Long He, Hongfeng Jiang, Mingjin Zhang, Wenjuan He, Zhengxi Hu, Ye Gu, Hongping Song, Yonghui Zhang
Poisonous weeds are a global problem since they not only hinder local economic development, but also cause ecological harm. Consolida rugulosa (family Ranunculaceae) is a weed that is widespread in Northwestern China and causes severe poisoning when ingested by livestock. In the present study, we purified the toxins in this plant and investigated their mechanism of action. Five natural diterpene alkaloids (compounds 1–5)—including two new compounds (1 and 2)—were isolated, and five semi-synthetic derivatives (6–10) were synthesised based on 4 or 5 for structure-activity analysis. The toxicity of the compounds was evaluated in vitro with lactate dehydrogenase (LDH) assay. All of the compounds—especially 1—stimulated LDH release in primary cultured rat myocardial cells, an effect that was blocked by the Na+ channel blocker lidocaine. Electrocardiography revealed that rats treated with 1 had severe arrhythmia, while heart Doppler echocardiography and analysis of serum biomarkers levels revealed that administration of 1 for 15 days induced changes in cardiac structure and myocardial enzyme levels. These effects were antagonised by lidocaine treatment. Thus, diterpene alkaloids are the main compounds responsible for the cardiotoxicity of C. rugulosa, which can be mitigated by co-administration of lidocaine.
Responses of duckweed (Lemna minor L.) to aluminum stress: Physiological and proteomics analyses Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-05 Chunlei Su, Yuji Jiang, Yaru Yang, Wei Zhang, Qinsong Xu
Aluminum (Al) is commonly considered an abiotic stress factor under acidic conditions. Duckweed (Lemna minor L.) has wide application in ecotoxicological research as a model organism and, in this study, its response to Al bioaccumulation was evaluated at morphological, physiological and proteomic levels. The Al accumulation in L. minor was accompanied by chlorosis and growth inhibition. Overproduction of superoxide and hydrogen peroxide, and decreased chlorophyll and protein contents, suggested that Al exposure induced oxidative stress. Inhibition of photosynthesis was evident in a significant decrease in maximum photosystem II quantum yield. There were 261 proteins, with significant changes in expression, successfully identified and quantified through isobaric tags for relative and absolute quantification (iTRAQ) analysis. Among the KEGG pathway enrichment proteins, those related to the citrate cycle and amino acid metabolism were predominantly up-regulated, whereas those associated with energy metabolism and glyoxylate and dicarboxylate metabolism were predominantly down-regulated. In addition, antioxidant enzyme related proteins played an important role in the response of L. minor to Al. The western blot analysis further validated the changes in photosynthetic related proteins. These results provide comprehensive insights into the physiological and molecular mechanisms of Al toxicity and tolerance in L. minor.
The regulatory role of COX-2 in the interaction between Cr(VI)-induced endoplasmic reticulum stress and autophagy in DF-1 cells Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Peng Chen, Na Geng, Dong Zhou, Yiran Zhu, Yuliang Xu, Kangping Liu, Yongxia Liu, Jianzhu Liu
Hexavalent chromium (Cr(VI)) is a common environmental pollutant. Exposure of Cr(VI) can lead to cell autophagy, but the preventive measures for diminishing Cr(VI)-induced autophagy need further study. COX-2 can be induced by several heavy metals and can lead to endoplasmic reticulum (ER) stress and autophagy; thus, COX-2, ER stress, and autophagy may be related. This study mainly investigated the role of COX-2 in the eIF2α-ATF4 pathway, which is a major pathway in cell autophagy. In this study, Cr(VI) was used as a xenobiotic to determine changes in the parameters of ER stress, autophagy, and COX-2 levels. At the same time, a clear contrast was obtained by assigning positive and negative controls of ER stress and autophagy. The results showed that during Cr(VI) invasion, the parameters of ER stress and autophagy (such as BiP, PERK, p62, LC3-II, and mTOR) were enhanced, similarly to the positive control of ER stress and/or the autophagy controls. Such enhancement is a protective mechanism for cell survival. Additionally, the COX-2 levels increased. Moreover, when COX-2 was inhibited, the PERK level remained high, whereas the LC3-II level decreased. This finding suggests that COX-2 specifically affects the interaction between ER stress and autophagy. Notably, this study reveals that Cr(VI) can induce ER stress and autophagy in DF-1 cells and that COX-2 plays an essential role in the interaction between ER stress and autophagy.
Effect of spraying direction on the exposure to handlers with hand-pumped knapsack sprayer in maize field Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Zhikang li, Wanli Liu, Changcai Wu, Dongmei She
Only less than one percent applied pesticides reach the target pest, the remainder spread out into the environment, effecting on workers, bystanders, consumers and so on. Handlers with manual knapsack sprayer are completely exposed to the pesticide spray plume when they deal with the pesticides. Those kinds of sprayer are widely used in developing countries, more than 75% of farmers using hand-pumped knapsack sprayer in China, yet rarely systematic studies had been focused on the typical applying scenario. The occupational exposure of pesticide is highly correlated with the pesticide spray plume flying time in the air in this scenario. Our study aimed to compare the estimated exposure level of handlers to chlorpyrifos sprayed at three spraying direction using a lever-operated knapsack in small farms in five agro-climatic zones of China. Experiments were performed by 24 farms in each province with three different crop heights (< 80 cm, spraying downward; 80–130 cm, spraying horizontal; and > 130 cm, spraying upward; eight farms for every direction) under typical field conditions. Each farmer covered a uniform area of 667 m2. The whole body dosimetry method and a personal air sampler were used to monitor the dermal and inhalation exposure. The estimated dermal exposure of the three spraying direction was 629, 1580, and 2140 mg/kg, respectively. The results showed that the total dermal exposure level increased with the spraying direction from downward to upward. Furthermore, appropriate cotton coveralls could reduce more than 90% of the total dermal exposure.
Biocorona formation contributes to silver nanoparticle induced endoplasmic reticulum stress Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Indushekhar Persaud, Jonathan H. Shannahan, Achyut J. Raghavendra, Nasser B. Alsaleh, Ramakrishna Podila, Jared M. Brown
Prior research has demonstrated cells exposed to silver nanoparticles (AgNPs) undergo endoplasmic reticulum (ER) stress leading to cellular apoptosis and toxicity, however, the fundamental mechanism underlying AgNP-induced ER stress is unknown. We hypothesize the biophysical interactions between AgNPs and adsorbed proteins lead to misfolded proteins to elicit an ER stress response. Our investigation examined rat aortic endothelial cells (RAEC) exposed to 20 or 100 nm AgNPs with or without a biocorona (BC) consisting of bovine serum albumin (BSA), high density lipoprotein (HDL) or fetal bovine serum (FBS) to form a complex BC. The presence of a BC consisting of BSA or FBS proteins significantly reduced uptake of 20 nm and 100 nm AgNPs in RAEC. Western blot analysis indicated robust activation of the IREα and PERK pathways in RAEC exposed to 20 nm despite the reduction in uptake by the presence of a BC. This was not observed for the 100 nm AgNPs. Hyperspectral darkfield microscopy qualitatively confirmed that the preformed BC was maintained following uptake by RAEC. Transmission electron microscopy demonstrated a size dependent effect on the sub-cellular localization of AgNPs. Overall, these results suggest that AgNP size, surface area and BC formation governs the induction of ER stress and alterations in intracellular trafficking.
Adsorption of gaseous elemental mercury on soils: Influence of chemical and/or mineralogical characteristics Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Andres J. Montoya, Jorge C. Lena, Cláudia C. Windmöller
Gaseous elemental Hg is stable enough to be transported over long distances. Some of the most important sources of Hg in the atmosphere are artisanal gold mining activities and forest fires. Both of these sources are particularly prevalent in the Amazonia region. Information regarding the capacity of soils for retaining Hg transported by the atmosphere is very important for understanding the metal cycle in the environment. The aim of this work was to study gaseous elemental Hg adsorption in soils with different physical and chemical characteristics. For this purpose, soils from different regions in Brazil and Colombia influenced or possibly influenced by gold mining activities and forest fires were studied. Hg adsorption tests were conducted by exposing soil samples to a gaseous elemental Hg atmosphere for 144 h. The total Hg concentration (THg) and Hg oxidation states were monitored using a direct Hg analyzer. Sample characterization analyses were performed. THg values obtained before the adsorption tests were 43–413 and 144–590 µg kg−1 for grain size fractions below 2 and 0.063 mm, respectively. The predominant species found was Hg2+, with abundance levels from 68% to 99%. The results show a wide range of enhanced Hg retention capacities among the samples, ranging from 13 to 2236 times the initial concentration, and the speciation results demonstrate a decrease in the oxidized species range, from 21% to 78%. The statistical analysis indicated the importance of Mn-bearing minerals for the processes of adsorption/oxidation of gaseous elemental Hg in soils. These results contribute to the elucidation of the processes that occur with Hg at the soil/atmosphere interface and may help to explain the high concentrations of Hg found in Amazonian soils where no gold mining activities are practiced.
Allantoin attenuates cadmium-induced toxicity in cucumber plants Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Sławomir Dresler, Barbara Hawrylak-Nowak, Jozef Kováčik, Martyna Pochwatka, Agnieszka Hanaka, Maciej Strzemski, Ireneusz Sowa, Magdalena Wójciak-Kosior
Concentration-dependent responses of cucumber plants to cadmium (Cd, 5–15 µM) and/or allantoin (Alla, 10–1000 µM) have been investigated to detect a possible protective role of Alla under Cd excess. After 14 days of exposure, Alla often considerably reversed Cd-induced inhibition of growth and reduction of the content of photosynthetic pigments. Higher Alla doses depleted the Cd amount in shoots, which could be related to citric acid (increase in the shoots but depletion in the roots in Cd+Alla treatments) rather than to phytochelatins (Alla had a negative impact on the phytochelatin accumulation). An increase in the Alla concentration suppressed Cd-induced spatial H2O2 appearance, which does not seem to be related to antioxidative enzymes (low impact of Alla on catalase, ascorbate peroxidase, and guaiacol peroxidase). On the contrary, shoot glutathione and mainly ascorbic acid accumulation strongly increased in Cd+Alla treatments, indicating their prominent role in Alla-induced amelioration of Cd-stimulated oxidative stress and growth retardation. Similarly, phenolic metabolites (total soluble phenols and flavonols) were slightly influenced by Alla and their antioxidative action was not expected. We conclude that Alla-mediated attenuation of Cd-induced toxicity relies on enhanced accumulation of glutathione and ascorbate in the shoot tissue mainly, rather than on elevated antioxidative enzyme activities.
Iron mediated hematological, oxidative and histological alterations in freshwater fish Labeo rohita Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Mamta Singh, Anindya Sundar Barman, Asem Lembika Devi, Ayam Gangarani Devi, Pramod Kumar Pandey
Iron is an essential element for many physiological functions of several organisms but in excess it causes toxicity. High iron content in water bodies of mountainous states is considered as one of the major factor, responsible for low productivity in aquaculture systems. But, till date comprehensive reports on the adverse effect of iron overload in aquatic organisms, especially cultured fishes are scanty. Therefore, the present study was undertaken to investigate the adverse effects of iron overload in economically important aquaculture fish species Labeo rohita. Three sub-lethal test concentration of iron (ferrous) viz., 1/16th, 1/8th and 1/4th of LC50 (post 96 h) i.e. 8.25, 16.51 and 33.01 mg L−1, respectively, were used for in vivo exposure. Blood cells and tissue samples of the control & exposed specimens were sampled at intervals of 24, 48, 72 and 96 h to assess alterations in hematological, oxidative stress and histological parameters. Significant changes in erythrocyte and leukocyte counts, hemoglobin, lipid peroxidation, antioxidant enzyme activity (super oxide dismutase and catalase) and tissue iron accumulation were observed in the exposed fish. Significant increase in lipid peroxidation, coupled with significant reduction in free radicals scavengers like super oxide dismutase and catalase revealed a compromised anti-oxidative defense mechanism in the fishes exposed to iron overload. Histological examination of gills and liver showed severe tissue injury and histological alternations. Severity was found to increase in time and concentration dependent manner. Perl's staining revealed accumulation of excess iron in liver of the exposed fish. The observed patho-physiological changes in the present study provide the most comprehensive insight of iron overload stress in L. rohita.
Foliar spraying of melatonin confers cadmium tolerance in Nicotiana tabacum L Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Meng Wang, Shuhui Duan, Zhicheng Zhou, Shibao Chen, Duo Wang
Melatonin is a multifunctional signaling molecule that regulates broad aspects of responses to environmental stresses in plants. Cadmium (Cd) is a persistent soil contaminant that is toxic to all living organisms. Recent reports have uncovered the protective role of melatonin in alleviating Cd phytotoxicity, but little is known about its regulatory mechanisms in plants. In this study, we found that foliar application of melatonin (in particular 100 μmol L−1) remarkably enhanced Cd tolerance of tobacco (Nicotiana tabacum L.) leaves, as evidenced by less Cd accumulation and alleviation of growth inhibition and photoinhibition, compared with nontreated Cd-stressed plants. The addition of melatonin also controlled oxidative damage of Cd on tobacco through direct scavenging and by enhancing the activities of antioxidative enzymes. Melatonin application promoted Cd sequestration in the cell wall and vacuoles based on the analysis of subcellular distribution of Cd in tobacco cells. Structural equation modeling (SEM) analysis revealed that melatonin-induced Cd tolerance in tobacco leaves was modulated by the expression of Cd-transport genes. Molecular evidence illustrated that modulation of IRT1, Nramp1, HMA2, HMA4, and HMA3 genes caused by melatonin could be responsible for weakening Cd uptake, Cd transportation to xylem, and intensifying Cd sequestration into the root vacuoles.
Oil sands process-affected water impairs the olfactory system of rainbow trout (Oncorhynchus mykiss) Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Ebrahim Lari, Dylan Steinkey, Parastoo Razmara, Effat Mohaddes, Greg G. Pyle
Oil sands process-affected water (OSPW), a byproduct of the extraction of bitumen in the surface mining of oil sands, is currently stored in massive on-site tailings ponds. Determining the potential effects of OSPW on aquatic ecosystems is of main concern to oil sands companies and legislators concerned about the reclamation of mining sites. In the present study, the interaction of OSPW with the chemosensory system of rainbow trout was studied. Using an electro-olfactography (EOG) technique, a 24 h inhibition curve was established and concentrations that inhibit the olfactory system by 20% and 80% (IC20 and IC80) were estimated at 3% and 22% OSPW, respectively. To study the interaction of exposure time and concentration along with the mechanism of the toxic effects, rainbow trout were exposed to 3% and 22% OSPW for 2, 24, and 96 h. An EOG investigation of olfactory sensitivity demonstrated a positive interaction between exposure time and concentration of OSPW concentration, because an increase in either or both elevated the inhibitory effect. To investigate whether or not structural damage of the olfactory epithelium could account for the observed inhibitory effects of OSPW on fish olfaction, the ultrastructure of the olfactory epithelium of exposed fish was investigated using scanning electron microscopy (SEM) and light microscopy (LM). The SEM micrographs showed no changes in the structure of the olfactory epithelium. The light micrographs revealed an increase in the number of mucous cells in 22% OSPW. The results of the present study demonstrated that exposure to OSPW impairs the olfactory system of rainbow trout and its effects increase gradually with increasing exposure time. The present study demonstrated that structural epithelial damage did not contribute to the inhibitory effects of OSPW on the olfactory system.
Soil pollution and toxicity in an area affected by emissions from a bauxite processing plant and a power plant in Gardanne (southern France) Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-04 Rahime Oral, Giovanni Pagano, Antonietta Siciliano, Maria Toscanesi, Maria Gravina, Aldo Di Nunzio, Anna Palumbo, Philippe J. Thomas, Franca Tommasi, Petra Burić, Daniel M. Lyons, Marco Guida, Marco Trifuoggi
Soil pollution and toxicity have been investigated in the Gardanne area (southern France) at a range of sites around a recognized pollution source, a bauxite processing plant (BPP), and a power plant (PP). Soil samples were submitted to inorganic and organic analyses and tested for toxicity in two invertebrate models. Inorganic analysis was based on determining elemental concentrations by ICP-MS, encompassing a total of 26 elements including 13 rare earth elements (REEs), of the soil samples and their leachates after 24 or 48 h in seawater. Organic analyses were performed by measuring the sums of 16 polycyclic aromatic hydrocarbons (PAHs) and of total hydrocarbons (C-10 to C-40). Bioassays were carried out on the early life stages of three sea urchin species (Arbacia lixula, Paracentrotus lividus and Sphaerechinus granularis), and on a nematode (Caenorhabditis elegans). Sea urchin bioassays were evaluated by the effects of soil samples (0.1–0.5% dry wt/vol) on developing embryos and on sperm, and scored as: a) % developmental defects, b) inhibition of sperm fertilization success and offspring damage, and c) frequencies of mitotic aberrations. C. elegans 24 h-mortality assay showed significant toxicity associated with soil samples. The effects of soil samples showed heightened toxicity at two groups of sites, close to the BPP main entrance and around the PP, which was consistent with the highest concentrations found for metals and PAHs, respectively. Total hydrocarbon concentrations displayed high concentrations both close to BPP main entrance and to the PP. Further studies of the health effects of such materials in Gardanne are warranted.
Food up-take and reproduction performance of Daphnia magna under the exposure of Bisphenols Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-03 Yanhua Liu, Zhengyu Yan, Ling Zhang, Zhujiangcai Deng, Jiafu Yuan, Shenghu Zhang, Jianqiu Chen, Ruixin Guo
Because the application of Bisphenol A (BPA) was restricted, many substitutes, such as Bisphenol F (BPF) and Bisphenol S (BPS), were developed as BPA substitutes. Therefore, environmental impacts of BPA and its substitutes on aquatic organisms should be concerned, especially their combined toxicity. In this study, the impacts of BPA, BPF, BPS and their mixture on the feeding behavior, reproduction and physiological function of daphnids were synthetically evaluated, involving the duration and mode of exposure. In short-term exposure tests, feeding rates of D. magna decreased after exposure to BPA, BPF, BPS and their mixture, while the inhibition reversed into stimulation in the recovery period. It may benefit from overcompensation of D. magna. In long-term exposure tests, the inhibition effect on the reproduction and growth of the exposed D. magna was difficult to recover, and only some experimental groups have a certain recovery. In conclusion, environmental risk of BPA, BPF, BPS and their mixture on the behavior of D. magna increased with prolonged exposure time. Moreover, relative activities of trypsin, amylase (AMS), acetylcholinesterase (AChE), carbonic anhydrase (CA), glutathione peroxidase (GPx) and super oxidase dimutase (SOD) of the exposed daphnids decreased in most treatment groups, indicating the disorder of digestive, nervous and antioxidative system of D. magna. Interestingly, inhibition of enzymes activities decreased with the increase of the exposure time, which implied the tolerance may be occurred.
Fate of tetracycline and sulfonamide resistance genes in a grassland soil amended with different organic fertilizers Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-01 Hui Lin, Stephen J. Chapman, Thomas E. Freitag, Carol Kyle, Junwei Ma, Yuyi Yang, Zulin Zhang
This study provided an assessment of the environmental fate of antibiotic resistance genes (ARGs) in a Scottish grassland field repeatedly treated with different organic fertilizers. The impacts of manure, biosolids and municipal food-derived compost on the relative abundances of tetracycline ARGs (tetA, tetB, tetC, tetG and tetW), sulfonamide ARGs (sul1 and sul2) and class 1 integron-integrase gene (IntI1) in soils were investigated, with inorganic fertilizer (NPK) as a comparison. The background soil with a history of low intensity farming showed a higher total relative abundance of tet ARGs over sul ARGs, with tetracycline efflux genes occurring in a higher frequency. In all treatments, the relative abundances of most ARGs detected in soils decreased over time, especially IntI1 and tet ARGs. This general attenuation of soil ARGs is a reflection of changes in the soil microbial community, which is supported by the result that almost all the soils at the end of the experiment had different bacterial communities from the untreated soil at the beginning of the experiment. Multiple applications of organic fertilizers to some extent counteracted the decreasing trend of soil ARGs relative abundances, which resulted in higher ARGs relative abundances in comparison to NPK, either by a lesser decrease of IntI1 and tet ARGs or an increase of sul ARGs. The enhancement of existing soil ARG prevalence by organic fertilizers was strongly dependent on the organic fertilizer type and the particular ARG. Compost contained the lowest relative abundance of inherent ARGs and had the least effect on the soil ARG decrease after application. The relative increase of tet ARGs caused by biosolids was larger than that of sul ARGs, while manure caused the opposite effect. Fertilization practices did not exert effective impacts on the soil bacterial community, although it caused significant changes in the profile of the ARG pool. Organic fertilization may thus accelerate the dissemination of ARGs in soil mainly through horizontal gene transfer (HGT), consistent with the enrichment of IntI1 in organic fertilized soils.
Photodegradation of fluazaindolizine in aqueous solution with graphitic carbon nitride nanosheets under simulated sunlight illumination Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-01 Nannan Pang, Hongfang Lin, Jiye Hu
The photodegradation of fluazaindolizine (FZDL) under simulated sunlight irradiation was accelerated by the catalysis of graphitic carbon nitride (g-C3N4). Under optimum conditions, such as 5 mg of amount and dispersion, the photodegradation half-life was dramatically enhanced to 2.7 h. More importantly, the pathway of degradation by g-C3N4 was different from both direct photolysis and the catalysis by titanium oxide, with particular negative ions of m/z 221 and 195, corresponding to the cleavage of sulfamide bond and the ring opening of imidazole, respectively. In addition, hydroxyl and superoxide radicals played important roles in photodegradation. The results enriched not only the study of FZDL photodegradation but also the application of g-C3N4. It also suggested the possibility of the water purification by photodegradation for pesticide removal in real life.
Effects of tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP) on sex-dependent alterations of thyroid hormones in adult zebrafish Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-12-01 Xiaoshan Liu, Yi Cai, Yao Wang, Suhua Xu, Kyunghee Ji, Kyungho Choi
Organophosphate flame retardants (OPFRs) have been widely used as alternatives to polybrominated diphenyl ethers for fire prevention. OPFRs are suspected of causing potential thyroid disruption in humans. In fish, their thyroid hormone modulation is reported but the mechanisms of this modulation are less understood. Thyroid-disturbing effects of OPFRs were evaluated using adult zebrafish (Danio rerio) following 14d exposure to tris(1,3-dichloro-2-propyl) phosphate (TDCPP) or triphenyl phosphate (TPP). Plasma concentrations of thyroid hormones were measured and transcriptions of several genes involved in thyroid function were quantified in brain, thyroid, and liver. Exposure to TDCPP or TPP led to significant decreases in plasma triiodothyronine (T3) and thyroxine (T4) concentrations in the male fish, while the increases were observed in the female fish. Exposure to the OPFRs also altered the transcription of regulatory genes and receptors in hypothalamus, pituitary, and thyroid of the fish in sex-dependent manner. In the male fish, transcriptions of corticotropin-releasing hormone (crh) and thyroid-stimulating hormone (tsh) in the brain were significantly up-regulated, probably as a compensation for hypothyroidism, but thyroglobulin (tg) and deiodinase 2 (dio2) were down-regulated in thyroid or liver. In contrast, in the females, transcriptions of crh and tsh genes were significantly down-regulated. These observations show that TDCPP and TPP exposure can lead to sex-dependent disruptions of thyroid hormone balances in the adult zebrafish through alterations of the hypothalamus-pituitary-thyroid (HPT) axis.
A pilot study on using biochars as sustainable amendments to inhibit rice uptake of Hg from a historically polluted soil in a Karst region of China Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-30 Ying Xing, Jianxu Wang, Jicheng Xia, Zhenmei Liu, Yonghang Zhang, Ying Du, Wanli Wei
We studied the addition of two biochars (rice shell biochar (RSB) and wheat straw biochar (WSB)) to soil at doses of 24–72 t/ha on the dynamics of pH, dissolved organic carbon (DOC), sulfate, Fe(III), and Fe(II), as well as on mercury (Hg) mobility in the pore water of a polluted paddy soil, throughout the rice-growing season. The effect of biochar addition to soil on rice biomass and Hg accumulation was also investigated. The key results showed that the addition of RSB or WSB to soil improved significantly the biomass of aboveground tissues of rice plants, particularly at higher dose treatments, compared with the control. The RSB treatment noticeably decreased Hg concentration in the pore water compared to the control, throughout the rice-growing season, and this decrease was likely due to the decreased Hg mobility by the RSB by promoting the level of sulfate in the pore water, which might be reduced to sulfide to combine with Hg to form Hg sulfides. The extent of Hg concentration reduction in the pore water was less pronounced in the WSB treatments relative to the RSB treatments. Addition of RSB to soil at doses of 24–72 t/ha decreased significantly Hg contents in the stalk, bran, hull and polish rice of rice plants compared to the non-treated rice (control), particularly Hg content in the polished rice was below the Chinese safety level (< 20 ng g−1, GB2762-2012). The WSB treatments showed limited effects on rice tissues Hg. Biochar (RSB) may offer a promising method for managing the risk of Hg in paddy field by inhibiting rice Hg uptake.
Preparation of tannin-immobilized gelatin/PVA nanofiber band for extraction of uranium (VI) from simulated seawater Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-30 Jie Meng, Xiaoyan Lin, Jian Zhou, Ruigang Zhang, Yan Chen, Xiaoyan Long, Ran Shang, Xuegang Luo
A novel gelatin/PVA composite nanofiber band loaded with bayberry tannin (GPNB-BT) was prepared by electrostatic spinning and crosslinking for extraction of uranium (VI) from simulated seawater. The influential factors of tannin loaded on the nanofiber band were investigated in detail. Surface morphology and fiber diameter of GPNB-BT were studied by Scanning Electron Microscopy (SEM). Functional groups of GPNB-BT were investigated by Fourier Transform Infrared Spectrometer (FTIR). The adsorption process and mechanism of uranium on GPNB-BT was characterized by Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). The results revealed that the BT had been stably solidified on the GPNB. Compared with other tannin-immobilized membranes, the nano-network structure of GPNB-BT with 200–400 nm diameter of fibers can promote solidification of tannins and improve adsorption capacity of GPNB-BT for uranium. The maximum adsorption capacity of the GPNB-BT for uranium is 170 mg/g at the optimal pH of 5.5 in 80 mg/L of initial uranium concentration and 1.4 μg/g even at extremely low initial concentration of 3 μg/L in the simulated seawater for 24 h. The GPNB-BT with good hydraulic properties, floatability and adsorption capacity for uranium is expected to be widely used in separation and enrichment of uranium in seawater and radioactive waste water.
Salinity tolerance of a rare and endangered unionid mussel, Popenaias popeii (Texas Hornshell) and its implications for conservation and water management Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-29 Michael A. Hart, Tom D. Miller, Charles R. Randklev
Unionid mussels are considered sensitive to salinity and there is growing concern in arid and semi-arid regions that declining flows coupled with anthropogenic impacts are amplifying natural salinity levels. In this study, we tested the effects of varying salinity concentrations (3.0, 4.0, 5.0, 6.0, 7.0 and 10.0 ppt NaCl) on survival of adult Popenaias popeii, (Texas Hornshell). This species occurs in the Rio Grande basin of Texas and northern Mexico, an arid to semi-arid stream plagued by salinization, and was recently listed as Endangered under the U.S. Endangered Species Act. We performed 2, 4, and 10-day toxicity tests on individuals from two disjunct populations: Laredo, TX, and the Lower Canyons of the Rio Grande near Big Bend National Park. We found no significant differences in LC50 estimates between populations at 96-hrs or 10-days but significant differences in TUD50s at 5 ppt between populations, which indicates that tolerance does not vary but sensitivity may between these populations. Overlaying LC50 estimates at 10-days for both populations on plots of salinity (ppt) measured over time, we show parts of the Rio Grande periodically approach or exceed 4.0 ppt, indicating these reaches are becoming unsuitable for P. popeii and populations within them at risk.
Bioaerosols emission and exposure risk of a wastewater treatment plant with A2O treatment process Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-14 Yunping Han, Kaixiong Yang, Tang Yang, Mengzhu Zhang, Lin Li
The characteristics of bioaerosol emissions from wastewater treatment plants (WWTPs) have attracted extensive attention. The anaerobic-anoxic-oxic (A2O) process, which uses the activated sludge approach to wastewater treatment, is the most widely used process in WWTPs. Concentration, size distribution, population, and exposure risk from bacteria and fungi in bioaerosols of WWTPs using the A2O process were studied in this work. The results showed that the maximum concentration of airborne bacteria (1.00 × 104 Colony Forming Units per cubic meter (CFU m−3)) and fungi (1.44 ×104 CFU m−3) occurred from the facility's aerobic tank, in summer. As one of the main factors affecting bioaerosol exposure risk, particle size distribution was related to season. The study found that particles larger than 3.3 µm in diameter were detected mainly in spring and summer, while particles less than 3.3 µm were detected mainly in autumn and winter, whether bacterial aerosol or fungal aerosol. In addition, pathogenic bacteria were observed in bioaerosols from WWTPs, with 18 of the 65 species of bacteria detected found to be potentially or opportunistically pathogenic, such as Chryseobacterium, Stenotrophomonas, Alcaligenes, Micrococcus, Pantoea, Enterobacter and Escherichia-Shigella. The presence of these pathogens further increased the exposure risk from bioaerosols. The results of an inhalation risk assessment for airborne bacteria and fungi indicated that potential adverse health risks for adults mainly occurred in spring, summer, and autumn. On this basis, it was concluded that WWTP operators should set up effective bioaerosol controls as soon as possible to protect the health of workers, and of residents near the plant.
Accumulation of heavy metals in metallophytes from three mining sites (Southern Centre Morocco) and evaluation of their phytoremediation potential Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-14 Laila Midhat, Naaila Ouazzani, Abdessamed Hejjaj, Ahmed Ouhammou, Laila Mandi
The current study aims to perform a field survey of three abandoned mining sites in the southern centre of Morocco to assess the recent metal pollution in soils and accumulation potential of plant species. Native plants and soils were sampled at several sites in the studied mines and analysed for Cu, Zn, Pb and Cd concentrations. Soils in the investigated sites proved to be deficient in major macronutrients and to contain toxic levels of Cu, Zn, Pb and Cd. Botanical survey of the prospected sites showed the abundance of diverse plant communities (46 species and 19 families), with no obvious toxicity symptoms. Results showed that the concentrations of heavy metals were different in the same plant species and from plant species to another. Eight plants of 46 species namely Hirschfeldia incana (L.) Lagr.-Foss, Citrullus vulgaris (L.) Schradi, Portulaca oleracea L., Stipa capensis Thunb., Lactuca viminea (L.) J.Presl & C.Presl, Forsskaolea tenacissima L., Lycium intricatum Boiss. and Hammada scoparia (Pomel) Iljin were considered as the best-performing specimens due to their high ability to accumulate multiple metals in their shoots and roots without being affected by excessive metal contents. This was confirmed by the transfer factors generally higher than 1. Consequently, these tolerant and native plant species could be used as tools for an effective phytorestoration of metal-contaminated sites.
Simultaneous atrazine degradation and E. coli inactivation by UV/S2O82-/Fe2+ process under KrCl excilamp (222 nm) irradiation Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-14 Svetlana Popova, Galina Matafonova, Valeriy Batoev
This study is the first to reveal that the iron-catalyzed photo-activation of persulfate (UV/PS/Fe2+system) under mercury-free KrCl excilamp irradiation (222 nm) is capable of simultaneous degradation of an organic pollutant and inactivation of a microorganism in aqueous media using the herbicide atrazine (ATZ) and E. coli as model contaminants, respectively. Deionized water, natural water and wastewater effluents, contaminated with 4 mg/L ATZ and/or 105 CFU/mL E. coli, were sequentially treated by direct UV, UV/PS and UV/PS/Fe2+ processes. Lowering the pH to 3.5 accelerated both the degradation and inactivation during the UV/PS/Fe2+ treatment of natural water. Comparison of the apparent UV dose-based pseudo first-order rate constants showed the negative effect of E. coli on ATZ degradation by decreasing rates in all of the examined water matrices. This can be due to the competitive effect between ATZ and bacterial cells for reactive oxygen species (ROS). By contrast, E. coli in the presence of ATZ was inactivated faster in natural water and wastewater (but not in deionized water), as compared to the case without ATZ. A scheme of possible synergistic inactivation under ROS exposure in water, containing ATZ, natural organic matter and chloride ions as primary constituents, was proposed. Radical scavenging experiments showed a major contribution of SO4•- to ATZ degradation by UV/PS/Fe2+ treatment of deionized water and natural water. The UV doses, required for 90% removal of ATZ from natural water and wastewater, achieve 160 mJ/cm2 (pH 5.5) and concurrently provide 99.99% E. coli inactivation. These results make the UV/PS/Fe2+ system with narrow band UV light sources promising for simultaneous water treatment and disinfection.
Nanoelemental selenium alleviated the mercury load and promoted the formation of high-molecular-weight mercury- and selenium-containing proteins in serum samples from methylmercury-poisoned rats Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-13 Yunyun Li, Yunpeng Ge, Ru Wang, Jiating Zhao, Hui Jing, Xiaoying Lin, Shaohua Ma, Yuxi Gao, Bai Li, Chunying Chen, Yu-Feng Li
Selenite (Se4+) has been found to counteract the neurotoxicity of methylmercury (MeHg) in MeHg-poisoned rats. However, Se4+ has narrow range between its toxic and beneficial effects. Nanoelemental selenium (SeNPs) was found to be less toxic than other forms of Se such as Se4+. In this study, the effects of SeNPs on the load of mercury (Hg) in rats were investigated. Hyphenated technique based on size-exclusion chromatography coupled with UV and inductively coupled plasma mass spectrometry (SEC-ICP-MS) detection and synchrotron radiation X-ray fluorescence spectroscopy (SR-XRF) were used to analyze the Hg-Se-containing proteins in the serum from MeHg-poisoned rats. The Hg-Se-containing fractions monitored by UV and ICP-MS were further characterized by MALDI-TOF-MS. Elevated serum Hg and Se levels were found in MeHg-poisoned rats after SeNPs treatment. Three main Hg-containing bands with molecular weights (MWs) of 25, 62 and 140 kDa were detected in the control samples. Treatment with SeNPs increased the Hg content in proteins at 62 and 170 kDa and decreased the Hg content at 25 kDa. The fraction with 25 kDa was assigned to metallothioneins (MTs), and fractions with 40 and 75 kDa were assigned to albumin. This study showed that the low-toxicity SeNPs could reduce the Hg load in the tissues and promote the formation of high molecular weight Hg- and Se-containing proteins in MeHg-poisoned rats.
Analysis of glycerophospholipid metabolism after exposure to PCB153 in PC12 cells through targeted lipidomics by UHPLC-MS/MS Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-13 Xinlu Wang, Yanyang Xu, Xiao Song, Qi Jia, Xining Zhang, Yongzhong Qian, Jing Qiu
Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) that have neurotoxicity, reproductive toxicity, hepatotoxicity and immunotoxicity in both animals and humans. Few studies have focused on the changes to endogenous glycerophospholipid metabolism caused by PCB153. To evaluate the relationships between exposure to PCB153 and specific endogenous glycerophospholipid metabolism, an ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was implemented in this study. Twenty-two endogenous glycerophospholipids in PC12 cells were analyzed after exposure to PCB153 at dosages of 0.05 μg mL−1, 0.5 μg mL−1 or 20 μg mL−1 for 120 h. PC(14:0/14:0), PE(16:0/18:1), PE(16:0/18:2), PS(18:0/18:1) and PI(16:0/18:1) were identified as potential biomarkers under the rules of t-test (P) value < 0.05 and variable importance at projection (VIP) value > 1. It was also found that the alterations at 0.05 μg mL−1 and 20 μg mL−1 PCB153 were similar at 120 h, while 0.5 μg mL−1 PCB153 presented an opposite trend. Additionally, significant upregulation of PC, PE and PS with the same fatty acid chains of 18:0/18:2 was found after exposure to 0.05 μg mL−1 and 20 μg mL−1 PCB153 at 120 h. This study revealed that PCB153 exposure modulated 22 endogenous glycerophospholipids in PC12 cells and provided the basis for the further study of PCB153 on the effects of glycerophospholipids on PC12 cells.
Phosphorus sorption behavior on sediments in Sanggou Bay related with their compositions by sequential fractionation Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-13 Xiaoyan Cao, Jiamei Zhu, Min Lu, Chengfeng Ge, Limin Zhou, Guipeng Yang
The surficial sediment samples collected from the Sanggou Bay in China were treated by a sequential extraction procedure. After removal of calcite, organic matter and Fe/Mn oxides, P adsorption onto the sediment residues was then evaluated through kinetic and thermodynamic characteristics. The sorption kinetic curves could be described by a two-compartment first order equation. The sorption isotherms fit well with the Langmuir and Freundlich equations. The HCl-treated sediments with calcite removed showed a rising fraction of the rapid step and a higher P adsorption potential compared with the un-extracted samples. For the clay minerals and silicate residue after NH2OH·HCl treatment, the rapid step fraction was dominant, the sorption capability was prohibited, and the process was much more reversible than the original and previously-generated samples. An increase of temperature was favorable for the sorption. Estimation of thermodynamic parameters showed that the process was spontaneous and endothermic, with an increased randomness at the solid–liquid interface. Compared with the un-extracted sediment, the thermodynamic parameters in our case changed slightly after HCl treatment and NH2OH·HCl treatment.
Phenolic metabolism and related heavy metal tolerance mechanism in Kandelia Obovata under Cd and Zn stress Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-13 Shan Chen, Qiang Wang, Haoliang Lu, Junwei Li, Dan Yang, Jingchun Liu, Chongling Yan
In the present study, a set of pot culture experiments was conducted to reveal how the metabolism process of phenolic compounds was affected by cadmium (Cd) and zinc (Zn) and to further uncover heavy metal tolerance mechanisms in Kandelia obovata. After 60d of treatment, the biomass and chlorophyll a content in the leaves were suppressed, but total phenolic compounds in roots and leaves were improved by the increasing gradient of Cd or Zn concentrations; Total phenolic compounds significantly increased by 3.6–44.6% in the roots, and by 0.4–126.6% in the leaves. At the meantime, the activity of Shikimate dehydrogenase (SKDH), cinnamyl alcohol dehydrogenase (CAD), and polyphenol oxidase (PPO) in the roots increased by 11.2–307.6%, 12.4–175.4% and − 2.7–392.8%, and the results were 3.4–69.5%, 1.7–40.0%, 16.0–99.7% in the leaves. Higher toxicity of Cd than Zn, as well as slight alleviating effect of 100 mg kg−1 Zn on 2.5 mg kg−1 Cd were found. Additionally, a significantly positive correlation coefficients for relationship between phenolic metabolism related enzyme activity and Cd/Zn contamination levels was found, and leaf SKDH, leaf CAD, and leaf PPO activities were moderately correlated with leaf Cd (r = 0.39, r = 0.43, and r = 0.57, respectively) and leaf Zn (r = 0.44, r = 0.41, r = 0.19, respectively) content, which indicate that Cd and Zn play a previously unrecognized but major role in phenolic compounds synthesis, transport, and metabolism in K. obovata. The results also provided evidence that the application of high levels of Cd and Zn was accompanied by three phenolic metabolism pathways participating in heavy metal tolerance process.
Changes in the gills of the European eel (Anguilla anguilla) after chronic exposure to environmental cocaine concentration Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-13 Anna Capaldo, Flaminia Gay, Vincenza Laforgia
The recent discovery of illicit drugs in the aquatic environment has raised concerns about the possible effects on the aquatic fauna, because of the pharmacological activity of these substances. Cocaine is an illicit drug widespread in surface waters since it is the third most widely used drug in North America, Western and Central Europe, and the second in Latin America and the Caribbean. The aim of this study was to evaluate the influence of environmental concentrations of cocaine on the gills of the European eel (Anguilla anguilla). The gills of male silver eels exposed to 20 ng L−1 of cocaine for fifty days were compared to control, vehicle control and post-exposure recovery ten days groups. The following parameters were evaluated: the thickness of the interlamellar epithelium (TIE), the length of the secondary lamellae (LSL) and the fraction of the interlamellar epithelium and the secondary lamellae occupied by the mucous cells (MC(IE-SL)FA) 3) the plasma cortisol and prolactin levels. After cocaine exposure, the gill epithelium appeared hyperplastic. The following changes were observed: proliferation in the interlamellar epithelium; partial and total fusion of the secondary lamellae, that appeared shortened and dilated; epithelial lifting and aneurism in the secondary lamellae. Moreover, in cocaine exposed eels, an increase in TIE and MC(IE-SL)FA and a decrease in LSL were observed. These changes were still present ten days after the interruption of cocaine exposure. Plasma levels of both cortisol and prolactin increased after cocaine exposure; ten days after the interruption of cocaine exposure, the plasma cortisol levels were still higher, whereas the plasma prolactin levels were lower, than control values. Our results show that even a chronic exposure to low environmental cocaine concentrations severely harms the eel gills, suggesting damages to their functions, and potentially affecting the survival of this species.
Enhancement of platinum biosorption by surface-displaying EC20 on Escherichia coli Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-12 Ling Tan, Hao Cui, Yong Xiao, Hang Xu, Meiying Xu, Haiyan Wu, Haigang Dong, Guanzhou Qiu, Xinxing Liu, Jianping Xie
To increase the platinum adsorption capacity of Escherichia coli (E. coli) biomass, we fused EC20 protein to the E. coli cell surface using an InaKN-based display system, which is the N-terminal region of ice nucleation protein that can be employed as a cell surface display motif. The media and culture conditions were optimized for EC20 (a phytochelatin analogue with 20 repeating units of glutamate and cysteine) expression and Pt (IV) biosorption. Furthermore, the adsorption process was elucidated from aspect of adsorption kinetics and equilibrium, and the characterization of blank and Pt-loaded cells were analyzed using SEM, AFM, TEM, FT-IR and XPS. Our study demonstrated that E. coli strain, which had InaKN-EC20 protein expressed on the cell surface, showed a great enhancement in Pt (IV) adsorption under optimized condition when comparing with that of original E. coli strain. The SEM-EDX analysis revealed that the cellular morphology has been changed in Pt-loaded cells, and the weight percent of platinum in the surface of E.coli increased substantially after displaying EC20 protein. Furthermore, intracellular platinum accumulation was detected in Pt-loaded EC20 cells since a clear peak of platinum exhibited, implying that cytoplasmic EC20 protein might also contribute to platinum accumulation. FTIR analysis revealed that the predominant functional groups in platinum adsorption were amine, carboxyl and phosphate groups.
Metal and metalloid exposure and oxidative status in free-living individuals of Myotis daubentonii Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-12 Sandra R. Ruiz, Tapio Eeva, Mirella Kanerva, Anna Blomberg, Thomas M. Lilley
Metal elements, ubiquitous in the environment, can cause negative effects in long-lived organisms even after low but prolonged exposure. Insectivorous bats living near metal emission sources can be vulnerable to such contaminants. Although it is known that bats can bioaccumulate metals, little information exists on the effects of metal elements on their physiological status. For example, oxidative status markers are known to vary after detoxification processes and immune reactions. Here, for two consecutive summers, we sampled individuals from a natural population of the insectivorous bat, Myotis daubentonii, inhabiting a site close to a metal emission source. We quantified metals and metalloids (As, Ca, Cd, Co, Cu, Mn, Ni, Pb, Se, Zn) from individual fecal pellets. We measured enzymatic antioxidants (GP, CAT, SOD), total glutathione (tGSH) and ratio between reduced and oxidized glutathione (GSH:GSSG) from their red blood cells together with biometrics, hematocrit and parasite prevalence. In general, metal concentrations in feces of M. daubentonii reflected the exposure to ambient contamination. This was especially evident in the higher concentrations of Cd, Co, Cu and Ni close to a smelter compared to a site with less contaminant exposure. Annual differences were also observed for most elements quantified. Sex-specific differences were observed for calcium and zinc excretion. SOD and CAT enzymatic activities were associated with metal levels (principal components of six metal elements), suggesting early signs of chronic stress in bats. The study also shows promise for the use of non-invasive sampling to assess the metal exposure on an individual basis and metal contamination in the environment.
Uptake and subcellular distribution of aluminum in a marine diatom Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-12 Qingxia Liu, Linbin Zhou, Fengjie Liu, Claude Fortin, Yehui Tan, Liangmin Huang, Peter G.C. Campbell
Aluminum (Al) is widespread in the environment including the ocean. The effects of Al on marine organisms have attracted more and more attention in recent years. However, the mechanisms of uptake of Al by marine organisms and the subcellular distribution of Al once assimilated are unknown. Here we report the uptake and subcellular distribution of Al in a marine diatom Thalassiosira weissflogii. Short-term (< 120 min) uptake experiments showed that the Al uptake rate by the diatom was 0.033 ± 0.013 fmol-1 cell-1 min-1 (internalization flux normalized to the exposure Al concentration of 2 µM = 0.034 ± 0.013 nmol m−2 min−1 nM−1). Subcellular fractionation experiments showed that the internalized Al was partitioned to subcellular components in the following order: granules (69 ± 5%) > debris (17 ± 4%) > organelles (12 ± 2%) > heat-stable peptides (HSP) (~2%) > heat-denaturable proteins (HDP) (< 1%), indicating that the majority of intracellular Al was detoxified and stored in inorganic forms. The subcellular distribution of Al in the diatom is different from that of Al in freshwater green algae, in which most of the internalized Al is partitioned to organelles. We also evaluated an artificial seawater-based EDTA rinse solution to remove Al adsorbed on the diatom cell surface. Overall, our study provides new information to understand the mechanisms of uptake of Al by marine diatoms, and the mechanisms responsible for the biological effects (both toxic and beneficial) of Al on the growth of marine phytoplankton, especially diatoms.
Chemical and microbiological characterization of cruise vessel wastewater discharges under repair conditions Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-10 Isaías Vicente-Cera, Javier Moreno-Andrés, David Amaya-Vías, Miriam Biel-Maeso, Marina G. Pintado-Herrera, Pablo A. Lara-Martín, Asunción Acevedo-Merino, Juan Antonio López-Ramírez, Enrique Nebot
Cruise ship wastewater discharges are pollution sources towards the marine environment that are poorly characterized. In this study, wastewater samples from cruise ships have been obtained during repair works in a shipyard. Different organic pollutants have been analyzed and their concentrations were similar to those in urban wastewaters for pharmaceuticals and fragrances, but higher for UV filters and PAHs. For the first time, cypermethrin, a pesticide highly toxic towards aquatic species, was found at relevant concentrations (>1 µg L^-1). The faecal microorganisms were for all parameters higher than 10^4 CFU 100 mL^-1, which together with the presence of antibiotic compounds in wastewater (e.g., triclosan), could potentially lead to the generation of antibiotic resistance bacteria (ARB). The historical position of cruise ships, determined from the Automatic Identification System (AIS), were used to define the time ships were underway, at port, or in repair. From ship's passenger and crew load, and from estimates of discharges the total volume of wastewater produced by these ships (371,000 m^3 year^-1) and the average flow (0.15 ± 0.03 m^3crew^-1 day^-1) were calculated.
Triphenyltin exposure affects mating behaviors and attractiveness to females during mating in male guppies (Poecilia reticulata) Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-10 Ji-Liang Zhang, Chun-Nuan Zhang, Er-Chao Li, Miao-Miao Jin, Mao-Xian Huang, Wei Cui, Yang-Yang Lin, Ya-Jun Shi
The impacts of triphenyltin (TPT) on ecological health have been of great concern due to their widespread use and ubiquity in aquatic ecosystems. However, little is known about the effects of TPT on the reproductive behaviors of fishes. Therefore, the present study was conducted to investigate the effects of TPT at environmentally relevant concentrations (0, 1 and 10 ng Sn/L) on the mating behaviors and the attractiveness to females during mating in male guppies (Poecilia reticulata). The results showed that TPT exposure disturbed the mating behaviors; the TPT-exposed male fish performed more sneaking attempts, but no changes in sigmoid courtship were displayed. The increases in sneaking attempts might be related to increases in testosterone levels induced by TPT exposure. In the context of a competing male, the TPT-exposed males were less attractive to females during mating. The decreases in attractiveness might be related to decreases in carotenoid-based coloration, shown as decreases in caudal fin redness values and skin carotenoid contents. In addition, TPT-induced total antioxidant capacities, the activities of superoxide dismutase and catalase, and the contents of malondialdehyde in liver and intestinal tissues indicated increases in oxidative stress. Both oxidative stress and coloration are linked to carotenoids. Thus, we speculated that the TPT-exposed males might use carotenoids to cope with increases in oxidative stress at the expense of carotenoid-based coloration. The disruption of mating behaviors and the decrease in attractiveness to females in male fish could result in reproductive failure. The present study underscores the importance of using behavioral tests as a sensitive tool in assessing the impact of pollutants present in aquatic environments.
Selenite mitigates cadmium-induced oxidative stress and affects Cd uptake in rice seedlings under different water management systems Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-10 Huang Qingqing, Liu Yiyun, Qin Xu, Zhao Lijie, Liang Xuefeng, Xu Yingming
Cadmium (Cd) is toxic throughout the food chain. Selenium (Se) can mitigate Cd accumulation in rice plants, although it is unclear why it has such effect. The objectives of this study were to investigate the effects of Se application on Cd-induced oxidative stress and antioxidant activities, and the combined effects of Se application and water management on the formation of iron plaque on the rice surface and Fe, Cd, and Se accumulation in rice plants. Rice seedlings were grown in Cd-contaminated soil with or without the addition of Se, and in aerobic or flooded conditions. Exogenous Se reduced Cd-induced oxidative stress. In the flooded treatment, exogenous selenite significantly decreased Cd concentrations in rice tissues, whereas it noticeably enhanced Cd concentrations in rice tissues in the aerobic treatment. Furthermore, selenite addition and flooding promote the formation of iron plaque and increase Fe concentrations in rice tissues. Pearson correlation analysis shows that plant Cd was significantly negatively correlated with Fe concentrations in rice tissues, and plant Fe was significantly positively correlated with Se concentrations in rice tissues, but no significant correlation was found between Cd and Se concentrations Thus, exogenous selenite may indirectly affect Cd uptake by influencing the formation of iron plaque on rice root surface, Fe uptake and Fe levels in rice.
Difenoconazole and linuron dissipation kinetics in carrots under open-field conditions Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-10 Lauana Pellanda Souza, Lêda Rita D’Antonino Faroni, Fernanda Fernandes Heleno, Frederico Garcia Pinto, Maria Eliana Lopes Ribeiro Queiroz, Lucas Henrique Figueiredo Prates
The dissipation of difenoconazole and linuron using an open-field experimental approach with carrots exposed to one-, two- and fivefold the recommended dose of the pesticides was evaluated to provide safe recommendation to ensure food safety of carrots. The pesticide residue analysis was performed with solid-liquid extraction with low temperature partitioning technique (SLE/LTP) followed by gas chromatography analysis. The recovery percentages of extracts obtained from samples of carrot passed through SLE/LTP extraction and fortified with difenoconazole and linuron pesticides varied from 93.4% to 106.3% and from 95.1% to 116.6%, respectively. The limit of detection for difenoconazole was 0.02 and 0.12 mg kg−1 for linuron. The limit of quantification for difenoconazole was 0.05 and 0.36 mg kg−1 for linuron. The degradation time for fifty percent of the applied pesticide at the different doses ranged from 2.4 to 3.6 days for difenoconazole and from 7.5 to 10.5 days for linuron. At the end of the pre-harvest interval, carrots treated with fivefold the recommended dose of both pesticides were considered unfit for consumption. Despite monitoring the degradation products of the applied pesticides by gas chromatography coupled to mass spectrometer, none degradation product was identified on the carrots.
Effects of cypermethrin (pyrethroid), glyphosate and chlorpyrifos (organophosphorus) on the endocrine and immune system of Salvator merianae (Argentine tegu) Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-09 Ana P. Mestre, Patricia S. Amavet, Agustín I. Vanzetti, Ma. Soledad Moleón, Ma. Virginia Parachú Marcó, Gisela L. Poletta, Pablo A. Siroski
Several geographical areas where Salvator merianae is distributed in Argentina are included in regions with agricultural activity and exposed to pesticide formulations. Some pesticides could affect defense mechanisms being able alter structures of some components of immune and endocrine systems. To assess the potential effects of pesticides in this reptile under seminatural conditions, on the immune system and endocrine responses in S. merianae we analyzed several blood parameters. Total (TWBCC), differential (DWBCC) white blood cells count, heterophils/lymphocytes index (H/L), lobularity index (LI), natural antibodies (NAbs) titres, complement system (CS), and corticosterone concentration were analyzed in animals exposed to a mixture of cypermethrin (25%), glyphosate (66.2%) and chlorpyrifos (48%) formulations. In addition, body size was considered in these analyzes. TWBCC and NAbs revealed lower values in organisms exposed to pesticides respect to a control indicating a possible immunosuppression effect. Besides, the LI showed a greater number of lobes in organism exposed demonstrating symptoms of chronic infection. In addition, we observed a reduced growth in these animals possibly related to a less energy investment in body mass to maintain an active defense against pesticides. Finally, we found high levels of plasma corticosterone in animals exposed to mix formulation that could demonstrate neuroendocrine axis activation. Other parameters like DWBCC, H/L index and activity of CS showed no differences in treated animals respect to control group, which could indicate low sensibility of these parameters to the concentration of pesticides used. Our results provide evidence of the toxic effects of pesticides on different immune system parameters, but also a trade-off among these parameters, corticosterone levels and growth. In this way, we can conclude that the formulated pesticides applied widely and constantly in the areas occupied by S. merianae, would be affecting its immune and endocrine systems and therefore its ability to defend against external agents. This kind of studies is of great interest to know the possible responses of wild species to anthropogenic disturbances such as pesticide contamination.
Integrative moringa and licorice extracts application improves Capsicum annuum fruit yield and declines its contaminant contents on a heavy metals-contaminated saline soil Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-09 El-Sayed M. Desoky, Ahmed S. Elrys, Mostafa M. Rady
Green approaches for improving plant performance using natural supplementations are highly seeking. Following a preliminary study conducted on contaminated saline (EC = 7.75 dS m−1) and normal (EC = 1.4 dS m−1) soils, two main field trials were conducted to study the potential effects of licorice root (LRE; 0.5%) and moringa seed (MSE; 0.5%) extracts, supplemented to soil through irrigation water (SA) and/or as foliar spray (FS), on performance, physio-biochemical components, antioxidant defense system, and contaminants contents of Capsicum annuum plants grown on heavy metals-contaminated saline soil. Both extracts were applied in single treatments such as LRE-SA, MSE-SA, LRE-FS, and MSE-FS or in integrations like LRE-SA+LRE-FS, LRE-SA+MSE-FS, MSE-SA+LRE-FS, and MSE-SA+MSE-FS. The preliminary study results showed significant reductions in plant performance (growth and yield), chlorophylls content and significant increase in Cd content due to heavy metals and salt stress. However, LRE and MSE applied singly or in combinations positively modified these parameters compared to the control (SA and FS were applied with tap water). On the other hand, these parameters were not responded to LRE and/or MSE applications on the normal soil. The main studies results showed that all single or integrative treatments significantly increased plant growth and yield, leaf contents of leaf photosynthetic pigments, free proline, total soluble sugars, N, P, and K+, ratio of K+/Na+, and activities of CAT, POX, APX, SOD, and GR. In contrast, contaminants; Na+, Cd, Cu, Pb and Ni contents in plant leaves and fruits were significantly reduced on heavy metals-contaminated saline soil compared to the control. Additionally, all integrative treatments significantly exceeded all single treatments in this concern. The integrative MSE-SA+LRE-FS was the best treatment that is recommended to be used to maximize pepper plant performances and minimize plant contaminant contents on contaminated saline soils.
Nostoc entophytum cell response to cadmium exposure: A possible role of chaperon proteins GroEl and HtpG in cadmium-induced stress Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-09 Leila Alidoust, Hossein Shahbani Zahiri, Hadi Maleki, Neda Soltani, Hojatollah Vali, Kambiz Akbari Noghabi
The present study is pursuing our previous research, focused on some aspects of Nostoc entophytum ISC32 cell response to the stress caused by exposure to cadmium at the cellular and molecular levels. Variations in the antioxidant system (catalase and ascorbate peroxidase activity) of N. entophytum ISC32 exposed to varying concentrations of Cd (2, and 5 mg/L) resulted in a significant increase in the activity of both catalase and peroxidase. Activity of these enzymes was, however, not significantly changed in the presence of Cd concentrations of 10 and 20 mg/L. Levels of lipid peroxidation, as measured by malondialdehyde (MDA) assay, were observed in response to exposure to Cd (20 mg/L). There was, however, a sharp drop in both antioxidant and lipid peroxidation activities of Cd treated cells after 5 days exposure, likely in consequence of cellular damage. The content of chlorophyll a and phycobiliproteins of living cells were altered under Cd-induced conditions. TEM images of cyanobacterial cells treated with Cd showed cell surface alteration and modification along with altered cellular microcompartments. Cyanobacterial cells treated with Cd at concentrations below the minimum inhibitory concentration (MIC) remained with no apparent structural changes. However, at a higher concentration of Cd (30 mg/L), a clear detachment effect was observed between the mucilage external layer and cell membrane which may be attributed to cell plasmolysis due to toxic effects of Cd. Subsequently, the thickness of the ring-shaped mucilage external layer increased likely as a result of the cell defense mechanisms against toxic concentrations of Cd. Characterization of cells treated with Cd (30 and 150 mg/L) by scanning electron microscopy (SEM) indicated cell shrinkage with varying degrees of distortion and surface wrinkling. Energy-dispersive X-ray spectrometry (EDS) analysis suggested that Cd was not present as nanoparticles within the cell, but in the form of salt or other molecular structures. The up-regulation of chaperons was confirmed for GroEL and HtpG using real-time PCR and northern blot analyses. Interestingly, the expression of GroEL was markedly increased at lower Cd concentration (5 mg/L). However, the ISC32 strain accrued higher levels of HtpG transcript in response to an elevated concentration of Cd (15 mg/L). This pattern seems to be related to the fast and early induction of GroEL, which may be necessary for induction of other factors and heat shock proteins such as HtpG in Cd-treated Nostoc cells. The result of this study paves the way for a more detailed exploration of Cd effects on the defense mechanisms of cyanobacteria. Our research also shed some light on how cyanobacterial cells have evolved to respond to the heavy metal toxicity at the cellular, molecular and ultrastructural levels.
Heavy metals concentrations in some commercially key species from Sicilian coasts (Mediterranean Sea): Potential human health risk estimation Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-09 Anna Traina, Gioacchino Bono, Maria Bonsignore, Francesca Falco, Marta Giuga, Enza Maria Quinci, Sergio Vitale, Mario Sprovieri
Trace elements were measured in the edible tissues of target marine species (Sardina pilchardus, Mullus barbatus, Mullus surmuletus, Merluccius merluccius and Parapenaeus longirostris) collected in some of the main ports of the Sicilian coast (southern Italy) in order to evaluate the potential human health risk associated to their consumption. Cadmium, Pb and Hg were below the tolerable limits reported by the European Union in foodstuffs (Commission Regulation (EC) 1881/2006) except for Hg in P. longirostris from one sampling site. The health risk for consumers was assessed both for adults and children calculating the estimated weekly intake (EWI), the target hazard quotient (THQ) and the lifetime cancer risk (CR) for each element. The EWI did not exceed the provisional tolerable weekly intake (PTWI) recommended by the European Food Safety Authority and THQs were < 1 in most cases. Further, the probabilistic distributions of health hazard were evaluated through Monte-Carlo simulation which confirmed a non-carcinogenic risk. With some exceptions related to As exposure, the results obtained definitively confirm the goodness of the fishery commercial resources in one of the most important seafood market of the central Mediterranean Sea and represent a positive data for the assessment of the good environmental status for descriptor 9 of the Marine Strategy Framework Directive in this area of the basin.
Disentangling the effects of the aqueous matrix on the potential toxicity of liquid pig manure in sub-tropical soils under semi-field conditions Ecotox. Environ. Safe. (IF 3.974) Pub Date : 2018-11-08 Julia Corá Segat, Dilmar Baretta, Luís Carlos Iuñes Oliveira Filho, José Paulo Sousa, Osmar Klauberg Filho
Inadequate application of liquid pig manure (LPM) may pose risks to the soil due to the potential contaminants that exists, as well as by the large water input that can originate excessive moisture. By using Terrestrial Model Ecosystems, this study aimed to evaluate the effect of application of LPM (82% moisture) using the application rates of 20, 50 and 150 m3 ha−1 and also of the corresponding amount of water to understand the origin of effects on the soil fauna of two sub-tropical soils. In general, the results obtained for the two soil types indicated that LPM (150 m3 ha−1) changed the composition of soil fauna, with an increase in the abundance of insect larvae and dipterans, but a decrease in the number of earthworms and enchytraeids. Microbial biomass, soil respiration and the nutrients Mg, K and P increased with the amount of LPM supplied to the soil. When analysing the effects of adding large volumes of water via the LPM, results showed that application did not originate significant effects on the parameters measured. The differences obtained when comparing both treatments were mainly attributed to the organic load brought by the LPM and not to the amount of water without LPM.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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