Groundwater resources of Kathmandu Valley in Nepal are under immense pressure from multiple stresses, including climate change. Due to over-extraction, groundwater resources are depleting, leading to social, environmental and economic problems. Climate change might add further pressure by altering groundwater recharge rates and availability of groundwater. Mapping groundwater resilience to climate change can aid in understanding the dynamics of groundwater systems, facilitating the development of strategies for sustainable groundwater management. Therefore, this study aims to analyse the impact of climate change on groundwater resources and mapping the groundwater resiliency of Kathmandu Valley under different climate change scenarios. The future climate projected using the climate data of RCM's namely ACCESS-CSIRO-CCAM, CNRM-CM5-CSIRO-CCAM and MPI-ESM-LR-CSIRO-CCAM for three future periods: near future (2010–2039), mid future (2040–2069) and far future (2070–2099) under RCP 4.5 and RCP 8.5 scenarios were bias corrected and fed into the Soil and Water Assessment Tool (SWAT), a hydrological model, to estimate future groundwater recharge. The results showed a projected decrease in groundwater recharge in future ranging from 3.3 to 50.7 mm/yr under RCP 4.5 and 19–102.1 mm/yr under RCP 8.5 scenario. The GMS-MODFLOW model was employed to estimate the future groundwater level of Kathmandu Valley. The model revealed that the groundwater level is projected to decrease in future. Based on the results, a groundwater resiliency map of Kathmandu Valley was developed. The results suggest that groundwater in the northern and southern area of the valley are highly resilient to climate change compared to the central area. The results will be very useful in the formulation and implementation of adaptation strategies to offset the negative impacts of climate change on the groundwater resources of Kathmandu Valley.

The importance and contribution of nitrogen compounds and the related microbial nitrogen cycling processes in fresh snow are not well understood under the current research background. We collected fresh snow samples from 21 cities that 80% are from China during 2016 and 2017. Principal component analysis showed that SO42− were in the first principal component, and N-compounds were the second. Furthermore, the main pollutant ions SO42− and NO3− were from anthropogenic sources, and SO42− contributed (61%) more to the pollution load than NO3− (29%), which were confirmed through a series of precipitation mechanism analysis. We selected five N-cycle processes (consist of oxidation and reduction processes) for molecular biology experiments, including Ammonia-oxidation process, Nitrite-oxidation process, Denitrification process, Anaerobic-ammoxidation process (Anammox) and Dissimilatory nitrate reduction to ammonium process (DNRA). Except ammonia-oxidizing archaeal (AOA) and bacterial (AOB) amoA genes (above 107 copies g−1), molecular assays of key functional genes in various nitrogen conversion processes showed a belowed detection limit number, and AOB abundance was always higher than AOA. The determination of the microbial transformation rate using the 15N-isotope tracer technique showed that the potential rate of five N-conversion processes was very low, which is basically consistent with the results from molecular biology studies. Taken together, our results illustrated that microbial nitrogen cycle processes are not the primary biological processes causing the pollution in China fresh snow.

Background Evidence regarding whether prenatal exposure to air pollution increases the risk of hypospadias remains limited. The aim of the study is to evaluate the association between exposure to ambient air pollution during early pregnancy and the incidence of hypospadias. Methods We conducted a 1:10 case-control study using the Taiwanese Birth Registry database. Male full-term infants reported to have hypospadias were defined as cases, and controls were randomly selected from male full-term infants without any congenital anomaly. The monthly average of ambient air pollutants, including PM10, PM2.5, PM2.5–10, NO2, NOx, O3, and O3 8-h maximum, from 3 months before conception to 6 months post conception was retrieved from air quality monitoring stations and interpolated to the level of township using the kriging method. Multivariable logistic regression models were utilized to evaluate the associations. Results A total of 200 hypospadias cases, with 2000 healthy controls sampled, were reported during 2007–2014. The results revealed that PM2.5 exposure during the first 3 months after conception (odds ratio [OR] = 1.29, 95% confidence interval [CI]: 1.01–1.65, per interquartile range [IQR] = 15.6 μg/m3) and O3 exposure during the first month after conception (OR = 1.40, 95% CI: 1.08–1.82, per IQR = 8.0 ppb) were associated with a higher incidence of hypospadias. Conclusions The results of the study suggest that early gestational exposure to ambient air pollution increases the risk of hypospadias among full-term infants.

Background Cigarette butts are some of the most common form of litter in the World, causing severe environmental damage. Analysing spatial distribution of cigarette butts in the urban environment may lead to useful insights for further interventions to reduce this form of litter. In this study, we present a GIS-based methodology to estimate the density of cigarette butts across a large urban area. Methods We collected information about discarded cigarette butts in outdoor public spaces by systematic social observation in a diverse sample of areas in Madrid, Spain. We used these data to estimate the density of cigarette butts in public spaces around the entire city by performing GIS analyses based on Kernel Density Estimations. Last, we validated these measures using on-field observations in a set of locations across the city. Results Hospitality venues and public transportation stops were the places with the highest concentrations of cigarette butts, followed by the entrances to educational venues and playgrounds. Central districts showed the highest amount of cigarette butts in contrast to peripheral ones. We found that our measure had good validity, with a correlation coefficient of 0.784. Discussion This is the first study estimating and mapping cigarette butt litter in a large urban area. We identified a set of outdoor public places with high concentrations of cigarette butts and found geographical unevenness in the distribution of this pervasive form of litter across the study area. Our findings demonstrate the ubiquitous nature of cigarette butts in the urban environment and the need for interventions to reduce its impact on both people's health and the environment.

Cobalt (Co) is an essential trace element but may cause toxic effects upon occupational or environmental exposure. The present study is aimed to determine the urine concentrations of Co in four years-old children in the INMA-Asturias cohort (Spain) and to assess the factors determining the observed levels. This cohort is located in a heavily industrialized zone with strong potential for metal exposure. Some diet components such as consumption of sweets were meaningfully associated with higher urine Co concentrations. Traffic pollution also showed a noteworthy positive association with Co levels. Family tobacco consumption did not show substantial association with the urine concentrations of this metal in the INMA-Asturias children. A significant inverse association between urine Co and venous blood ferritin was found. Iron deficiency anemic children had significantly higher concentrations of Co than those with normal levels, e.g. median values 1.9 μg/g creatinine and 1.0 μg/g creatinine, respectively. This association could be explained by an increased expression of DMT1, a divalent metal transporter that captures higher levels of iron in deficiency states of this metal. This transporter is non-specific and not only captures iron but also other divalent metals such as Co. The presence of this metal in iron deficiency anemic children may represent an additional disturbing health factor that must be considered during treatment.

Since Nassim Taleb coined black swan as an event that occurred as a complete surprise for everybody, the metaphor of the black swan has been applied to a much wider variety of events. Black swan events now comprise events that are a surprise for some but not for others, events that have a low likelihood, events that were not believed to be possible but still proved to be possible, events that were dismissed as being too improbable to worry about but happened anyway. For a decision maker the black swan problem is choosing where to put effort to prevent, or mitigate events for which there are warnings, or for which the possibility has been put forward. Does the fact that there are thousands of books written about fire breathing dragons warrant the development of an Anti-Dragon Defense Shield? The black swan may have been a surprise for Willem de Vlamingh in 1697, it was not a surprise for the inhabitants of Australia, for which the appearance of tall white humans was their “black swan event”. In this paper we explore the options available to decision makers when confronted with the various sorts of swan (or dragon) events.

Background Ozone is currently one of the most important air pollutants. Volatile organic compounds (VOCs) can easily react with atmospheric radicals to form ozone. In-field measurement of VOCs may help in estimating the local VOC photochemical pollution level. Method This study examined the spatial and temporal distribution characteristics of VOCs during winter at three typical sites of varying classification in China; industrial (Guangzhou Economic and Technological Development District (GETDD)), urban (Guangzhou higher education mega center (HEMC)), and rural (Pingyuan county (PYC)), using Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS). Results The concentrations of total VOCs (TVOCs) at the GETDD, HEMC and PYC sites were 352.5, 129.2 and 75.1 ppb, respectively. The dominant category of VOCs is nitrogen-containing VOCs (NVOCs, accounting for 43.3% of TVOCs) at GETDD, of which C4H11N (m/z+ = 74.10, butyl amine) was the predominant chemical species (80.5%). In contrast, oxygenated VOCs (OVOCs) were the most abundant at HEMC and PYC, accounting for 60.2% and 64.1% of the total VOCs, respectively; here, CH4O (m/z+ = 33.026, methanol) was the major compound, accounting for 40.5% of the VOCs at HEMC and 50.9% at PYC. The ratios of toluene to benzene (T/B) were calculated for different measured sites, as the ratios of T/B can reveal source resolution of aromatic VOCs. The average contributions to total ozone formation potentials (OFP) of the total measured VOCs in each area were 604.9, 315.9 and 111.7 μg/m3 at GETDD, HEMC and PYC, respectively; the highest OFP contributors of the identified VOCs were aliphatic hydrocarbons (AlHs) at GETDD, aromatic hydrocarbons (AHs) at HEMC, and OVOCs at PYC. Conclusions OFP assessment indicated that the photochemical pollution caused by VOCs at GETDD was serious, and was also significant in the HEMC region. The dominant VOC OFP groups (AlHs and AHs) should be prioritized for control, in order to help reduce these effects.

Solid or semisolid matrices polluted with fecal remnants can be highly loaded with pathogens, especially viruses, and play a substantial role in the persistence and dispersion of pathogens in the water cycle. Water quality regulations and guidelines are increasingly including bacteriophages infecting enteric bacteria as indicators of fecal and/or viral pollution. However, more data are needed about viral indicators in contaminated solids to develop effective sanitation strategies for the management of raw and treated sludge, fecal sludge, manures and slurries. Also, the exact role of sediments and soil in the transmission cycle of viral pathogens still needs to be determined. This review aims to provide an update on available data for concentrations of indicator bacteriophages in different solid matrices as well as their resistance to treatments and persistence in solids. The conclusion reached is that there is a need for improved and standardized methodologies for bacteriophage extraction, detection and enumeration in solids. Reports indicate that these contain higher levels of somatic coliphages in comparison with traditional bacterial indicators and F-specific RNA coliphages. Water body sediments and soil have been found to be notable reservoirs of somatic coliphages, which are more persistent in nature and resistant to sludge treatments than Escherichia coli and fecal coliforms and F-specific RNA coliphages. Thus, somatic coliphages show up as excellent complementary indicators for the prediction of pathogenic viruses in solids.

The aim of this paper is to assess the water quality from several lakes in Rodnei Mountains National Park, in order to establish the extent to which the anthropic activities, such as livestock and tourism affect the water characteristics. The paper presents the quality status of 13 water samples, collected from different mountain lakes from Romania, by monitoring 25 quality indicators, 21 metals and metalloids. The results indicate relatively high content of NH4+ (0.96 mg/L), NO2− (0.240 mg/L), Ca (38.44 mg/L), Mg (4.35 mg/L), Fe (288 mg/L), Cu (34.46 μg/L) and high values for turbidity (5.31 NTU), chemical oxygen demand (10.00 mgO2/L) and suspended materials (88.0 mg/L). Microbiological analyses were performed for 14 types of bacteria. In some samples, the faecal coliforms (1100 bacteria/mL), faecal streptococci (39 bacteria/mL) and aerobic heterotrophic bacteria at 37 °C (300 bacteria/mL) were relatively in a high content. The metal pollution indices (heavy metal pollution index –HPI, heavy metal evaluation index –HEI and the degree of contamination -Cd) indicated as well that the water samples presented no metal pollution. Values ranged from 5.17 to 27.84 for HPI, 0.55 to 5.07 for HEI and −8.45 to −3.93 for Cd were obtained. The water quality index (WQI) indicated excellent and good quality for the studied samples, with a mean of 22.6 and a range from 11.4 to 46.9.

The significant applications of pyrethroid insecticides in agro-ecosystem and household environments have raised serious environmental concerns. Environmental bioremediation has emerged as an effective and eco-friendly approach to remove or neutralize hazardous compounds. Bioaugmentation accelerates pyrethroid degradation in liquid cultures and soil. Pyrethroid-degrading microorganisms have been extensively studied to cope with pyrethroid residues. Microorganisms primarily hydrolyze the ester bonds of pyrethroids, and their degradation pathways have been elaborated. The functional genes and enzymes involved in microbial degradation have also been screened and studied. Carboxylesterase plays a key role in pyrethroid degradation by cleaving its carboxylester linkage. The catalytic mechanism is dependent on a specific catalytic triad, consisting of three amino acid residues (glutamine, histidine, and serine) within the active site of the carboxylesterase enzyme. Pyrethroid-degrading strains and enzymes have proven to be effective for the bioremediation of pyrethroid-contaminated environments. In this review, we have summarized newly isolated pyrethroid-degrading strains and proposed the degradation pathways along with key functional genes/enzymes. To develop an efficient bioremediation strategy, pyrethroid-degrading microorganisms should be comprehensively explored.

Background Fetal epigenetic programming plays a critical role in development. DNA methyltransferase 3 alpha (DNMT3A), which is involved in de novo DNA methylation (DNAm), is a prime candidate gene as a mediator between prenatal exposures and birth outcomes. We evaluated the relationships between in utero arsenic (As) exposure, birth outcomes, and DNMT3A DNAm. Methods In a prospective Bangladeshi birth cohort, cord blood DNAm of three DNMT3A CpGs was measured using bisulfite pyrosequencing. Maternal toenail As concentrations at birth were measured to estimate in utero exposure. Among vaginal births (N = 413), structural equation models (SEMs) were used to evaluate relationships between DNMT3A methylation, log2 (toenail As), birth weight, and gestational age. Results In an adjusted SEM including birth weight and gestational age, maternal toenail As levels were associated with DNMT3A DNAm (B = 0.40; 95% CI: 0.15, 0.66) and gestational age (B = −0.19 weeks; 95% CI: 0.36, −0.03). DNMT3A DNAm was associated with gestational age (B = −0.10 weeks; 95% CI: 0.16, −0.04) and birth weight (B = −11.0 g; 95% CI: 21.5, 0.4). There was a significant indirect effect of As on gestational age mediated through DNMT3A DNAm (B = −0.04; 95% CI: 0.08, −0.01), and there were significant indirect effects of maternal toenail As levels on birth weight through pathways including gestational age (B = −14.4 g; 95% CI: 29.2, −1.9), DNMT3A DNAm and gestational age (B = −3.1 g; 95% CI: 6.6, −0.8), and maternal weight gain and gestational age (B = −5.1 g; 95% CI: 9.6, −1.5). The total effect of a doubling in maternal toenail As concentration is a decrease in gestational age of 2.1 days (95% CI: 0.9, 3.3) and a decrease in birth weight of 29 g (95% CI: 14, 46). Conclusions DNMT3A plays a critical role in fetal epigenetic programming. In utero arsenic exposure was associated with greater methylation of CpGs in DNMT3A which partially mediated associations between prenatal As exposure and birth outcomes. Additional studies are needed to verify this finding.

Polycyclic aromatic hydrocarbons (PAHs) are a class of pollutants that ubiquitously present in environment and hard to be degraded by microorganisms. Herein, we reported a novel photocatalytic-bacterial coupled removal system to treat PAH-polluted water. Using pyrene as the model pollutant, we demonstrated that the removal percentage of different groups was in order: 63.89% ± 1.03% (Vis-Biological) > 61.27% ± 1.08% (UV-Biological) > 59.58% ± 1.15% (UV) > 57.41% ± 1.13% (Vis) > 6.65% ± 0.72% (Biological) > 1.70% ± 0.34% (Control), showing the coupled system significantly improved the removal percentage of pyrene. Additionally, we observed that the coupled system driven by visible light showed higher removal percentage than UV light, exhibiting a good potential for future application. Sequencing analysis of 16S rRNA genes showed that alpha diversity (richness, evenness and diversity) got promoted and data of the relative abundance showed that Pseudomonadaceae was substituted as the dominant bacteria for Planococcaceae, with some other functional bacteria quickly acclimatizing in the bacterial community. Difference analysis indicated that over half of top fifteen genera were generally different significantly (p < 0.001) among two different samples, and UV light altered structure and composition of bacterial community more than visible light. Functional features’ change suggested that the bacterial community not only protected itself but also participated in degrading pyrene. Overall, our study offered a new method for PAH degradation and contributed to further understanding of coupled catalytic-bacterial degradation processes.

Acknowledging the difficulty of modelling pollution conveyed by urban runoff, this contribution presents a first pan-European quantification of loads from this diffuse source. We estimate annual loads of 5-days biochemical oxygen demand (BOD5), nitrogen (N), phosphorus (P) and total suspended solids (TSS) using a simple event mean concentration (EMC) model initially proposed by Heaney et al., 1976. On a European scale, this yields discharges corresponding to untreated wastewater of about 31 million population equivalents (PE) for BOD5, about 18.5 million PE for N and P and about 280 million for TSS. These represent 51% of the pollution coming from treated wastewater for BOD5, 15% for N and P and 461% for TSS. Although the model applied for the assessment was developed more than 40 years ago, the results are consistent with those obtained using more recent parameterizations, except for a tendency to underestimate P loads. Although lack of data on pollution from urban runoff makes model verification impossible, and the uncertainty on EMC models is known to be very high, urban runoff emerges as a significant source of pollution, and should be properly addressed as such. Reducing runoff volume from urban areas through improved water retention is not only key to pollution control, but also a no-regret option thanks to its co-benefits, especially when incorporated at early stages of planning and design.

Background Prenatal exposures to ambient air pollution and traffic have been associated with adverse birth outcomes, and may also lead to an increased risk of obesity. Obesity risk may be reflected in changes in body composition in infancy. Objective To estimate associations between prenatal ambient air pollution and traffic exposure, and infant weight and adiposity in a Colorado-based prospective cohort study. Methods Participants were 1125 mother-infant pairs with term births. Birth weight was recorded from medical records and body composition measures (fat mass, fat-free mass, and adiposity [percent fat mass]) were evaluated via air displacement plethysmography at birth (n = 951) and at ∼5 months (n = 574). Maternal residential address was used to calculate distance to nearest roadway, traffic density, and ambient concentrations of fine particulate matter (PM2.5) and ozone (O3) via inverse-distance weighted interpolation of stationary monitoring data, averaged by trimester and throughout pregnancy. Adjusted linear regression models estimated associations between exposures and infant weight and body composition. Results Participants were urban residents and diverse in race/ethnicity and socioeconomic status. Average ambient air pollutant concentrations were generally low; the median, interquartile range (IQR), and range of third trimester concentrations were 7.3 μg/m3 (IQR: 1.3, range: 3.3–12.7) for PM2.5 and 46.3 ppb (IQR: 18.4, range: 21.7–63.2) for 8-h maximum O3. Overall there were few associations between traffic and air pollution exposures and infant outcomes. Third trimester O3 was associated with greater adiposity at follow-up (2.2% per IQR, 95% CI 0.1, 4.3), and with greater rates of change in fat mass (1.8 g/day, 95% CI 0.5, 3.2) and adiposity (2.1%/100 days, 95% CI 0.4, 3.7) from birth to follow-up. Conclusions We found limited evidence of an association between prenatal traffic and ambient air pollution exposure and infant body composition. Suggestive associations between prenatal ozone exposure and early postnatal changes in body composition merit further investigation.

Health problems caused by environmental pollution may affect the process of urbanization in China. Therefore, this study, against the backdrop of promoting new-type urbanization, evaluates the level of China's urbanization comprehensively using the fully arranged polygon graphical index method. It uses a dynamic threshold panel model to study the potential non-linear relationship between environmental pollution (wastewater, sulfur dioxide, and solid wastes) and urbanization under different health costs of residents. Our findings show that environmental pollution has inhibited the improvement of comprehensive urbanization, population urbanization, economic urbanization, and living conditions urbanization, but promoted living environment urbanization, in China. It is worth noting that with the rise in residents' health costs, the inhibiting effect of environmental pollution on comprehensive urbanization, population urbanization, economic urbanization, and living conditions urbanization in China has gradually increased, but on living environment urbanization, it has decreased.

Skatole is the key malodorous compound in livestock and poultry waste and wastewater with a low odor threshold. It not only causes serious nuisance to residents and workers, but also poses threat to the environment and human health due to its biotoxicity and recalcitrant nature. Biological treatment is an eco-friendly and cost-effective approach for skatole removal, while the bacterial resources are scarce. Herein, the Burkholderia strain was reported to efficiently degrade skatole for the first time. Results showed that strain IDO3 maintained high skatole-degrading performance under the conditions of pH 4.0–9.0, rotate speed 0–250 rpm, and temperature 30–35 °C. RNA-seq analysis indicated that skatole activated the oxidative phosphorylation and ATP production levels in strain IDO3. The oxidoreductase activity item which contained 373 differently expressed genes was significantly impacted by Gene Ontology analysis. Furthermore, the bioaugmentation experiment demonstrated that strain IDO3 could notably increase the removal of skatole in activated sludge systems. High-throughput 16S rRNA gene sequencing data indicated that the alpha-diversity and bacterial community tended to be stable in the bioaugmented group after 8 days operation. PICRUSt analysis indicated that xenobiotics biodegradation and metabolism, and membrane transport categories significantly increased, consistent with the improved skatole removal performance in the bioaugmented group. Burkholderia was survived and colonized to be the predominant population during the whole operation process (34.19–64.00%), confirming the feasibility of Burkholderia sp. IDO3 as the bioaugmentation agent in complex systems.

Background Hydraulic fracturing together with directional and horizontal well drilling (unconventional oil and gas (UOG) development) has increased substantially over the last decade. UOG development is a complex process presenting many potential environmental health hazards, raising serious public concern. Aim To conduct a scoping review to assess what is known about the human health outcomes associated with exposure to UOG development. Methods We performed a literature search in MEDLINE and SCOPUS for epidemiological studies of exposure to UOG development and verified human health outcomes published through August 15, 2019. For each eligible study we extracted data on the study design, study population, health outcomes, exposure assessment approach, statistical methodology, and potential confounders. We reviewed the articles based on categories of health outcomes. Results We identified 806 published articles, most of which were published during the last three years. After screening, 40 peer-reviewed articles were selected for full text evaluation and of these, 29 articles met our inclusion criteria. Studies evaluated pregnancy outcomes, cancer incidence, hospitalizations, asthma exacerbations, sexually transmitted diseases, and injuries or mortality from traffic accidents. Our review found that 25 of the 29 studies reported at least one statistically significant association between the UOG exposure metric and an adverse health outcome. The most commonly studied endpoint was adverse birth outcomes, particularly preterm deliveries and low birth weight. Few studies evaluated the mediating pathways that may underpin these associations, highlighting a clear need for research on the potential exposure pathways and mechanisms underlying observed relationships. Conclusions This review highlights the heterogeneity among studies with respect to study design, outcome of interest, and exposure assessment methodology. Though replication in other populations is important, current research points to a growing body of evidence of health problems in communities living near UOG sites.

Introduction It is unknown if high concentration of airborne grass pollen, where subtropical grasses (Chloridoideae and Panicoideae) dominate, is a risk factor for respiratory health. Here we systematically reviewed the association between airborne grass pollen exposure and asthma emergency department (ED) presentations and hospital admissions in subtropical climates. Objectives A systematic review was performed to identify and summarise studies that reported on respiratory health (asthma ED presentations and hospital admissions) and airborne grass pollen exposure in subtropical climates. Methods Searches were conducted in: MEDLINE, Web of Science, Scopus, CINAHL (EBSCO), Embase and Google Scholar databases (1966–2019). Risk of bias was assessed using a validated quality assessment tool. A meta-analysis was planned, however due to the heterogeneity in study design it was determined inappropriate and instead a narrative synthesis was undertaken. Results Nineteen studies were identified for inclusion, with a total of 598,931 asthma ED presentation participants and 36,504 asthma hospital admission participants in six countries (Australia, India, Israel, Italy, Spain, USA). The narrative synthesis found airborne grass pollen appears to have a small and inconsistent increase on asthma ED presentations (judged as: probably little effect n = 5, may have little effect n = 4, no effect n = 2 and uncertain if there is an effect n = 4) and hospital admissions (judged as: probably increase slightly n = 2 probably little effect n = 1, may have a little effect n = 1, no effect n = 3 and we are uncertain if there is an effect n = 4) in the subtropics. Furthermore, the reported effect sizes were small and its clinical relevance may be difficult to discern. Conclusion Exposure to airborne grass pollen appears to have a small and inconsistent increase on asthma ED presentations and hospital admissions in the subtropics. These findings are comparable to reported observations from studies undertaken in temperate regions.

Background Exposure to mixture of neurotoxic metals such as lead, mercury and cadmium occurs at a specific point of time. When exposed to metal mixtures, one metal may act as an agonist or antagonist to another metal. Thus, it is important to study the effects of exposure to a combination of metals on children's development using advance statistical methods. Objectives In this study, we explored the effects of prenatal metal exposure including lead, mercury and cadmium in early pregnancy (12–20 weeks), late pregnancy (>28 weeks), and at birth on neurodevelopment of infants at 6 months of age. Methods We included 523 eligible mother-child pairs from the mothers and children environmental health (MOCEH) study, a prospective birth cohort study in Korea. We used linear regression, Bayesian kernel machine regression (BKMR) and generalized additive models (GAM), to evaluate the effects of exposure to metal mixtures on neurodevelopment of infants aged 6 months. The Korean version of Bayley scale of infant and toddler development-II was used to measure the child's neurodevelopment. Results Linear regression models showed a significant negative effect of lead exposure during late pregnancy on the mental development index (MDI) [β = -2.51 (−4.92, −0.10)] scores of infants aged 6 months following co-exposure to mercury. Further, linear regression analysis showed a significant interaction between late pregnancy lead and mercury concentrations. BKMR analysis showed similar results as those obtained in linear regression models. These results were also replicated in the GAM. Stratification analysis showed that greater than 50 percentile concentration of mercury in late pregnancy potentiated the adverse effects of lead in late pregnancy on MDI [β = −4.33 (−7.66, −1.00)] and psychomotor development index (PDI) [β = −5.30 (−9.13, −1.46)] at 6 months of age. Prenatal cadmium exposure did not show a significant association with MDI and PDI at 6 months in the linear regression or BKMR analysis. Conclusion Based on all the statistical methods used, we demonstrated the effect of combined exposure to metals on the neurodevelopment of infants aged 6 months, with significant interaction between lead and mercury.

Asthma and allergic rhinitis (or hay fever) are ubiquitous, chronic health conditions that seasonally affect a sizeable proportion of the population. Both are commonly triggered or exacerbated by environmental conditions including aeroallergens, air quality and weather. Smartphone technology offers new opportunities to identify environmental drivers by allowing large-scale, real-time collection of day-to-day symptoms. As yet, however, few studies have explored the potential of this technology to provide useful epidemiological data on environment-symptom relationships. Here, we use data from the smartphone app ‘AirRater’ to examine relationships between asthma and allergic rhinitis symptoms and weather, air quality and pollen loads in Hobart, Tasmania, Australia. We draw on symptom data logged by app users over a three-year period and use time-series analysis to assess the relationship between symptoms and environmental co-variates. Symptoms are associated with particulate matter (IRR 1.06, 95% CI: 1.04–1.08), maximum temperature (IRR 1.28, 95% CI: 1.13–1.44) and pollen taxa including Betula (IRR 1.04, 95% CI: 1.02–1.07), Cupressaceae (IRR 1.02, 95% CI: 1.01–1.04), Myrtaceae (IRR 1.06, 95% CI: 1.02–1.10) and Poaceae (IRR 1.05, 95% CI: 1.01–1.09). The importance of these pollen taxa varies seasonally and more taxa are associated with allergic rhinitis (eye/nose) than asthma (lung) symptoms. Our results are congruent with established epidemiological evidence, while providing important local insights including the association between symptoms and Myrtaceae pollen. We conclude that smartphone-sourced data can be a useful tool in environmental epidemiology.

The Mediterranean Basin is undergoing a warming trend with longer and warmer summers, an increase in the frequency and the severity of heat waves, changes in precipitation patterns and a reduction in rainfall amounts. In this unique populated region, which is characterized by significant gaps in the socio-economic levels particularly between the North (Europe) and South (Africa), parallel with population growth and migration, increased water demand and forest fires risk - the vulnerability of the Mediterranean population to human health risks increases significantly. Indeed, climatic changes impact the health of the Mediterranean population directly through extreme heat, drought or storms, or indirectly by changes in water availability, food provision and quality, air pollution and other stressors. The main health effects are related to extreme weather events (including extreme temperatures and floods), changes in the distribution of climate-sensitive diseases and changes in environmental and social conditions. The poorer countries, particularly in North Africa and the Levant, are at highest risk. Climate change affects the vulnerable sectors of the region, including an increasingly older population, with a larger percentage of those with chronic diseases, as well as poor people, which are therefore more susceptible to the effects of extreme temperatures. For those populations, a better surveillance and control systems are especially needed. In view of the climatic projections and the vulnerability of Mediterranean countries, climate change mitigation and adaptation become ever more imperative. It is important that prevention Health Action Plans will be implemented, particularly in those countries that currently have no prevention plans. Most adaptation measures are “win-win situation” from a health perspective, including reducing air pollution or providing shading solutions. Additionally, Mediterranean countries need to enhance cross-border collaboration, as adaptation to many of the health risks requires collaboration across borders and also across the different parts of the basin.

Human exposure to PM2.5, represented by population-weighted mean PM2.5 concentration (cρ), declines under three conditions: (1) mean PM2.5 concentration declines, (2) PM2.5 concentration within urban areas goes through more of a decrease than within rural areas, or (3) city planning relocates people into cleaner areas. Decomposing these effects on human exposure is essential to guide future environmental policies. The lack of ground PM2.5 observations limits the assessment of human exposure to PM2.5 over China. This study proposed a novel diagnostic framework using satellite observations to decompose the variation in cρ resulting from change in the mean PM2.5 concentration, spatial difference in PM2.5 change, and demographic change. In this framework, we decomposed cρ into mean PM2.5 concentration (c0) and pollution-population-coincidence induced PM2.5 exposure (PPCE). We then used this framework to decompose the variation in cρ over China within three recent Five-Year Plans (FYPs) (2001–2015). The results showed that the decline in c0 reduced cρ in most provinces within the eleventh and twelfth FYPs. The spatial difference in PM2.5 change reduced the PPCE and cρ in most provinces within the tenth and twelfth FYPs, with the most substantial reduction rate of −3.64 μg m−3·yr−1 in Tianjin within the twelfth FYP. Rural-to-urban migration resulting from rapid urbanization, however, increased the PPCE and cρ (by as much as 0.22 μg m−3·yr−1) in all provinces except Taiwan within all three FYPs. The demographic change reduced cρ in Taiwan because of the migration of population into less polluted areas. To better reduce human exposure, it is recommended that control efforts further target populous residential areas and urbanization planning relocates people into less polluted areas. Our decomposition framework paves a new way to decompose the human exposure to other air pollutants in China and other regions.

Ciguatera fish poisoning (CFP) is one of the most devastating food-borne illnesses caused by fish consumption. Ciguatoxins (CTXs) are potent neurotoxins synthesized by the benthic microalgae Gambierdiscus spp. and Fukuyoa spp. that are transmitted to fish by grazing and predation. Despite the high incidence of CFP, affecting an estimated number of 50,000 persons per year in tropical and subtropical latitudes, the factors underlying CTXs occurrence are still not well understood. Toxin transfer and dynamics in fish and food-webs are complex. Feeding habits and metabolic pathways determine the toxin profile and toxicity of fish, and migratory species may transport and spread the hazard. Furthermore, CTX effect on fish may be a limiting factor for fish recruitment and toxin prevalence. Recently, new occurrences of Gambierdiscus spp. in temperate areas have been concomitant with the detection of toxic fish and CFP incidents in non-endemic areas. CFP cases in Europe have led to implementation of monitoring programs and fisheries restrictions with considerable impact on local economies. More than 400 species of fish can be vectors of CTXs, and most of them are high-valued commercial species. Thus, the risk uncertainty and the spread of Gambierdiscus have serious consequences for fisheries and food safety. Here, we present a critical review of CTXs impacts on fish, fisheries, and humans, based on the current knowledge on CFP incidence and CTXs prevalence in microalgae and fish.

Aquaculture wetlands, particularly those located within urban areas, are fragile ecosystems which are generally heavily impacted by urban and aquaculture activities. However, there are, to date, no reports on adverse effects related to polycyclic aromatic hydrocarbons (PAHs) in sediments from aquaculture wetlands in metropolitan areas. The characterization, sources, and incidence of adverse effects on aquatic biota of PAHs were studied in the riverine and estuarine sediments of the Rongjiang River in an aquaculture wetland in Chaoshan metropolis. The total PAH concentrations varied from 46.0 to 1665.2 ng/g (dry weight), with a mean of 246.4 ng/g, indicating lower concentrations than those of other comparable rivers and estuaries worldwide. High-molecular-weight PAHs were the major PAH species, with fluorene, benzo(b)fluoranthene, and benzo(a)pyrene as the dominant components. These PAHs are likely to be mainly derived from oil and coal/biomass combustion. Probability risk assessment indicated a moderate PAH ecological risk in the Rongjiang River and its estuary (RJE). Accordingly, a comprehensive management plan should be established to ensure sustainable aquaculture wetlands.

Traditional food consumption for Indigenous peoples is associated with improved nutrition and health but can also pose potential risks via exposure to contaminants. Polycyclic aromatic hydrocarbons (PAHs) are compounds of interest due to their widespread presence (e.g., their metabolites are detected in up to 100% of the Canadian population) and their toxicological potential. To better understand the range of exposures faced by Indigenous populations in northern Canada and to address a contaminant of emerging concern identified by the Arctic Monitoring and Assessment Programme, a multi-year biomonitoring study investigated levels of PAH exposure in subarctic First Nations communities of the Northwest Territories, Canada. Secondary data analysis of banked samples from a subset of the cross-sectional study was done. PAHs and cotinine markers in the urine samples (n = 97) of participants from two regions from the Mackenzie Valley (Dehcho and Sahtú) was completed by liquid and gas chromatography coupled with mass spectrometry. Also, participants completed a 24-hr recall food survey. When compared according to age/sex categories, the GM of several biomarkers (1-hydroxypyrene, 1-naphthol, 2-hydroxyfluorene, 2-hydroxyphenanthrene, 2-naphthol, 3-hydroxyfluorene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyfluorene, 9-hydroxyphenanthrene) appeared higher than observed for the general Canadian population. The PAHs levels observed were, however, below clinical levels associated with adverse health outcomes. Altogether, these elevated biomarkers are metabolites of pyrene, naphthalene, fluorene and phenanthrene. Statistically significant non-parametric associations were observed between several biomarkers and i) the consumption of cooked meat in the last 24 h; and, ii) smoking status (self-reported status and adjusted on urine cotinine level). This work is the first to report PAH levels in a northern Canadian population and provides local baseline data for monitoring the effects of changes to climate and lifestyle over time. These findings will support regional and territorial decision makers in identifying environmental health priorities.

Glyphosate-based herbicides, such as Roundup®, are the most widely used non-selective, broad-spectrum herbicides. The release of these compounds in large amounts into the environment is susceptible to affect soil quality and health, especially because of the non-target effects on a large range of organisms including soil microorganisms. The soil filamentous fungus Aspergillus nidulans, a well-characterized experimental model organism that can be used as a bio-indicator for agricultural soil health, has been previously shown to be highly affected by Roundup GT Plus (R450: 450 g/L of glyphosate) at concentrations far below recommended agricultural application rate, including at a dose that does not cause any macroscopic effect. In this study, we determined alterations in the transcriptome of A. nidulans when exposed to R450 at a dose corresponding to the no-observed-adverse-effect level (NOAEL) for macroscopic parameters. A total of 1816 distinct genes had their expression altered. The most affected biological functions were protein synthesis, amino acids and secondary metabolisms, stress response, as well as detoxification pathways through cytochromes P450, glutathione-S-transferases, and ABC transporters. These results partly explain the molecular mechanisms underlying alterations in growth parameters detected at higher concentrations for this ascomycete fungus. In conclusion, our results highlight molecular disturbances in a soil fungus under conditions of apparent tolerance to the herbicide, and thus confirm the need to question the principle of “substantial equivalence” when applied to plants made tolerant to herbicides.

Background Exposure to the environmental toxicant mercury (Hg) has been associated with immune dysregulation, including autoimmune disease, but few human studies have examined methylmercury (MeHg) exposure from fish consumption. Objectives We examined associations between MeHg exposure and biological markers of autoimmunity and inflammation while adjusting for long chain polyunsaturated fatty acids (LCPUFA). Method At age 19 years, hair total Hg (Y19Hg), LCPUFA status, a panel of 13 antinuclear antibodies (ANA), total serum immunoglobulins (Ig) IgG, IgA, and IgM and serum markers of inflammation (IL-1, IL-2, IL-6, IL-10, C-reactive protein (CRP), IFN-γ, TNF-α) were measured in the Seychelles Child Development Study (SCDS) Main Cohort (n = 497). Multivariable regression models investigated the association between Y19Hg and biomarkers, adjusting for prenatal total hair Hg (MatHg) and other relevant covariates, and with and without adjustment for LCPUFA. Results With each 1 ppm increase in Y19Hg (mean 10.23 (SD 6.02) ppm) we observed a 4% increased odds in a positive Combined ANA following adjustment for the n6:n3 LCPUFA ratio (β = 0.036, 95%; CI: 0.001, 0.073). IgM was negatively associated with Y19Hg (β = −0.016, 95%CI: 0.016, −0.002) in models adjusted for n-3, n-6 LCPUFA and when separately adjusted for the n-6:n-3 LCPUFA ratio. No associations were observed with MatHg. Total n-3 LCPUFA status was associated with reduced odds of a positive anti-ribonuclear protein (RNP) A. The n-3 LCPUFA were negatively associated with IL-6, IL-10, CRP, IFN-γ, TNF-α and positively with TNF-α:IL-10. There were positive associations between the n-6:n-3 ratio and IL-6, IL-10, CRP, IFN-γ, TNF-α and a negative association with TNF-α:IL-10. Discussion The Y19Hg exposure was associated with higher ANA and lower IgM albeit only following adjustment for the n-3 LCPUFA or the n-6:n-3 LCPUFA ratio. The clinical significance of these findings is unclear, but warrant follow up at an older age to determine any relationship to the onset of autoimmune disease.

Alachlor, a chloroacetanilide endocrine disruptor herbicide is precarious for humans as well as the environment. Though banned by the European Union and classified as moderately hazardous by WHO, yet it is nevertheless used in several countries posing austere human and environmental health issues. Alachlor attenuation was scrutinized through simulated biodegradation experiments using soil-isolated microbes. Bio-disintegrative assays of pure three fungal and one bacterial strain; Aspergillus flavus (AF), Penicillium chrysogenum (PC), Aspergillus niger (AN) and Xanthomonas axonopodis (XA), respectively were utilized. Initial Alachlor concentration (10 mg/L) was prepared with individual microbial suspension and monitored for 35 d. Alachlor bio-transformation was analyzed quantitatively and qualitatively by gas chromatography mass spectroscopy. XA and AN displayed maximal potential to metabolise the herbicide while forming residues; 1-chloroacetyl, 2,3- dihydro-7 ethylindole, 7 ethylindole, 7-ethyl-3-methyl-2-methoxy-2,3-dihydroindole, N- (2,6-diethylphenyl)-methyleneamine and 7-Ethyl-N-methylindole. Alachlor degradation by AF, PC, AN and XA was found to be 17.1%, 5.5%, 72.6% and 82.1%, respectively, after 35 d. Microbes have displayed cometabolism as the main mechanism for Alachlor degradation. This research can influence imperative and significant environmental friendly bio-remedial strategies for xenobiotic eradication.

Background Globally, dengue, Zika virus, and chikungunya are important viral mosquito-borne diseases that infect millions of people annually. Their geographic range includes not only tropical areas but also sub-tropical and temperate zones such as Japan and Italy. The relative severity of these arboviral disease outbreaks can vary depending on the setting. In this study we explore variation in the epidemiologic potential of outbreaks amongst these climatic zones and arboviruses in order to elucidate potential reasons behind such differences. Methodology We reviewed the peer-reviewed literature (PubMed) to obtain basic reproduction number (R0) estimates for dengue, Zika virus, and chikungunya from tropical, sub-tropical and temperate regions. We then used this data to compute R0 estimates for temperate and sub-tropical climate zones, which were estimated from outbreak curves in the initial outbreak phase. Lastly we compared these estimates across climate zones, defined by latitude. Results Of 2115 studies, we reviewed the full text of 128 studies and included 65 studies in our analysis. Our results suggest that the R0 of an arboviral outbreak depends on climate zone, with lower R0 estimates in temperate zones on average (R0 = 2.03) compared to tropical (R0 = 3.44) and sub-tropical zones (R0 = 10.29). The variation in R0 was considerable, ranging from 0.16 to 65. The largest R0 was for dengue (65) and was estimated by the Ross-Macdonald model in the tropical zone, whereas the smallest R0 of 0.16 was for Zika virus and was estimated statistically from the outbreak curves in a sub-tropical zone. Conclusions The results indicate climate zone to be an important determinant of the basic reproduction number, R0, for dengue, Zika virus, and chikungunya. The role of other factors as determinants of R0, such as methods, environmental and social conditions, and disease control should be further investigated. The results suggest R0 may increase in temperate regions in response to global warming and highlight the increasing need for strengthening preparedness and control operations.

Introduction Bisphenol F (BPF) and bisphenol S (BPS) are chemical substitutes for, and may have similar physiological effects to, bisphenol A (BPA). Bisphenols provoke endocrine disorders and are cytotoxic, oxidize hemoglobin, and induce morphological changes in human red blood cells (RBC). It is more sensitive to changes in the RBC number and hemoglobin (Hb) level during pregnancy. Therefore, we investigated the effects of bisphenols (BPs) and their substitute compounds on hemopoiesis and the serum biochemical parameters of pregnant women. Methods The study population comprised 196 pregnant women from the MAKE cohort study, recruitment for which occurred from 2017 to 2019. We measured the levels of BPA, BPF and BPS in urine samples and collected data on socioeconomic, lifestyle, and environmental factors at visits to the hospital. The associations between the levels of the three BPs and biochemical parameters were analyzed by multiple linear regression. Results The geometric mean urinary concentrations of specific gravity adjusted BPA, BPF, and BPS were 2.1, 0.2, and 0.1 μg/L, respectively. There was a significant negative association between the urinary concentration of BPA and the Hb level (β = −0.5, p = 0.02). After stratifying by the median concentrations of the three BPs, the maternal urinary BPA level had a significantly negative effect on the RBC count, HB level, and hematocrit in the high BPA concentration group (RBC, β = - 0.5, p = 0.001; Hb, β = −1.4, p = 0.002; Hct, β = −5.0, p = 0.001). Conclusions BPA has a harmful effect on hemato-biochemical changes that occur during pregnancy. Further studies should investigate the relation between widespread exposure to bisphenols and effects on human health.

The current study observed the effect of the synergistic interaction of urban heat island (UHI) and heatwaves (HWs) which is different from the sum of their separate effects on the medium-sized town of Nicosia, Cyprus. From an analysis of hourly meteorological records of eight consecutive years (2007–2014) we defined HWs with respect to air temperature (T95-over the 95th percentile air temperatures) as well as the heat index (HI65-heat index over 65degC) and studied their effects on the local UHI phenomenon. Both heatwave types were characterized by increased air temperature, lower wind speed and increased absolute humidity. HWs defined using the heat index (HI65) occurred more frequently and persisted for a longer period of time. UHI was intensified to about 0.9–1.3 °C during daytime hours under both HW definitions which was attributed to the evaporation of dew deposited on the upper top layer of soil that suppressed higher temperatures in the rural station due to a prolonged cooling effect. Model estimates of dew formation overnight and evaporation in the morning hours are hypothesized to be the main contributing factor in keeping rural air temperatures lower, thus increasing the UHI intensity. The results emphasize the critical role of latent cooling and evapotranspiration as a mitigation factor affecting extreme local temperatures.

Bioaerosols have been associated with adverse respiratory-related health effects and are emitted in elevated concentrations from composting facilities. We used modelled Aspergillus fumigatus concentrations, a good indicator for bioaerosol emissions, to assess associations with respiratory-related hospital admissions. Mean daily Aspergillus fumigatus concentrations were estimated for each composting site for first full year of permit issue from 2005 onwards to 2014 for Census Output Areas (COAs) within 4 km of 76 composting facilities in England, as previously described (Williams et al., 2019). We fitted a hierarchical generalized mixed model to examine the risk of hospital admission with a primary diagnosis of (i) any respiratory condition, (ii) respiratory infections, (iii) asthma, (iv) COPD, (v) diseases due to organic dust, and (vi) Cystic Fibrosis, in relation to quartiles of Aspergillus fumigatus concentrations. Models included a random intercept for each COA to account for over-dispersion, nested within composting facility, on which a random intercept was fitted to account for clustering of the data, with adjustments for age, sex, ethnicity, deprivation, tobacco sales (smoking proxy) and traffic load (as a proxy for traffic-related air pollution). We included 249,748 respiratory-related and 3163 Cystic Fibrosis hospital admissions in 9606 COAs with a population-weighted centroid within 4 km of the 76 included composting facilities. After adjustment for confounders, no statistically significant effect was observed for any respiratory-related (Relative Risk (RR) = 0.99; 95% Confidence Interval (CI) 0.96–1.01) or for Cystic Fibrosis (RR = 1.01; 95% CI 0.56–1.83) hospital admissions for COAs in the highest quartile of exposure. Similar results were observed across all respiratory disease sub-groups. This study does not provide evidence for increased risks of respiratory-related hospitalisations for those living near composting facilities. However, given the limitations in the dispersion modelling, risks cannot be completely ruled out. Hospital admissions represent severe respiratory episodes, so further study would be needed to investigate whether bioaerosols emitted from composting facilities have impacts on less severe episodes or respiratory symptoms.

Thyroid hormones (THs) are one of the most important hormones, playing key roles in the regulation of various physiological functions. Although THs have important function in human, in vitro test methods based on human cells are currently insufficient to effectively screen and test TH-related endocrine disrupting chemicals (EDCs). We established a TH agonist TA assay using the adenocarcinomic human alveolar basal epithelial cell line A549 to test and screen potential TH agonists. To establish the TH agonist TA assay, a TRE-secNluc-IRES-EGFP reporter cassette was constructed and transfected into the A549 cell line using a retrovirus. We evaluated the TH agonistic properties of several chemicals which were tested by existing thyroid agonists testing method (OECD GD 207). Comparing the results of the TH agonist TA assay with the OECD GD 207, T3, T4, tiratricol, and tetrac (natural TH and 3,3′,5,5′-tetraiodothyroacetic acid derivatives), which are TH agonists according to the OECD GD 207, also tested positive in the TH agonist TA assay using the A549 cell line. These results suggested that the TH agonist TA assay developed in this study using a human cell line can provide the information, such as accuracy and specificity to TH agonistic properties of chemicals.

Maternal exposure to toxic and essential trace elements represents a surrogate of exposure to the unborn child. Variables of exposure as sociodemographic, lifestyles and diet may contribute to different exposure of pregnant women to specific trace elements. Blood, urine and cord blood samples of 53 pregnant women of the HEALS-EXHES cohort, recruited in Reus (Catalonia, Spain) between 2016 and 2017, were analysed for the concentrations of As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Se and Zn. Univariate and multivariate models were built in order to assess associations between element concentrations in each matrix, and variables obtained by questionnaires on mothers’ characteristics and dietary habits. Results showed several significant associations between various variables and essential trace and toxic elements. Age was associated with higher levels of Cd and Pb in cord blood samples. Multiparous women showed lower levels of Cd in maternal blood and Pb in both maternal and cord blood than nulliparous women. Hispanic mothers presented higher levels of blood As and lower levels of blood Se compared to mothers of different ethnicity. Higher education level was associated with higher As and Hg concentrations in both maternal and cord blood samples. Higher annual income diminished the level of Pb in maternal blood. Smoking in pregnancy incremented the levels of Cd in mothers’ blood. Alcohol consumption may affect the absorption of Cu, Mn and Zn. Supplementations with multivitamins, folic acid and iron showed effects on elements as Cr, Mn, Se and Zn. Regarding food group intake, bluefish incremented Pb levels, while canned fish and seafood affected levels of some elements as As, Hg, Cu and Se. Other elements such as Mn and Pb were influenced by the intake of different kinds of foods. The present results showed that some modifiable lifestyles and food intakes could be the target of interventions to help pregnant women to maintain suitable concentrations of essential elements and lower levels of toxic ones, and to improve consequently neonatal health outcomes.

Background Fetal programming of the endocrine system may be affected by exposure to perfluoroalkyl substances (PFAAs), as they easily cross the placental barrier. In vitro studies suggest that PFAAs may disrupt steroidogenesis. “Mini puberty” refers to a transient surge in circulating androgens, androgen precursors, and gonadotropins in infant girls and boys within the first postnatal months. We hypothesize that prenatal PFAA exposure may decrease the concentrations of androgens in mini puberty. Objectives To investigate associations between maternal serum PFAA concentrations in early pregnancy and serum concentrations of androgens, their precursors, and gonadotropins during mini puberty in infancy. Methods In the prospective Odense Child Cohort, maternal pregnancy serum concentrations of five PFAAs: Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were measured at median gestational week 12 (IQR: 10, 15) in 1628 women. Among these, offspring serum concentrations of dehydroepiandrosterone (DHEA), dehydroepiandrosterone-sulfate (DHEAS), androstenedione, 17-hydroxyprogesterone (17-OHP), testosterone, luteinizing (LH) and follicle stimulating hormones (FSH) were measured in 373 children (44% girls; 56% boys) at a mean age of 3.9 (±0.9 SD) months. Multivariate linear regression models were performed to estimate associations. Results A two-fold increase in maternal PFDA concentration was associated with a reduction in DHEA concentration by −19.6% (95% CI: −32.9%, −3.8%) in girls. In girls, also, the androstenedione and DHEAS concentrations were decreased, albeit non-significantly (p < 0.11), with a two-fold increase in maternal PFDA concentration. In boys, no significant association was found between PFAAs and concentrations of androgens, their precursors, and gonadotropins during mini puberty. Conclusion Prenatal PFDA exposure was associated with significantly lower serum DHEA concentrations and possibly also with lower androstenedione and DHEAS concentrations in female infants at mini puberty. The clinical significance of these findings remains to be elucidated.

Background Pregnant women are exposed to a number of pesticides which are widely used in China. Their potential risks on reproduction and infants are still unknown. Objective We aimed to investigate whether infant's birth weight and length of gestation were associated with levels of various pesticides in maternal blood based on Nanjing Medical University (NMU) affiliated hospitals data and meta-analysis, and also to explore the possible intermediate metabolomics pathways. Methods Eligible subjects (n = 102) were included in this study from the affiliated hospitals of NMU. Gas chromatography tandem mass spectrometry (GC/MS) and Q-Exactive mass spectrometer (QE) were used to detect 37 pesticides (9 organophosphorus pesticides, 7 organochlorine pesticides, 5 carbamate pesticides, and 16 others) and 161 metabolites (53 in animo acid metabolism 47 in lipid metabolism, 18 in carbohydrate metabolism, 14 in nucleotide metabolism and 29 in other metabolisms) in maternal blood, respectively. Multi-linear regression and Bayesian kernel machine regression (BKMR) were performed to identify the association of single/mixed pesticide exposure in maternal blood with birth weight and length of gestation. Moreover, we conducted a meta-analysis including additional 2497 subjects to evaluate whether exposure to key pesticide, β-hexachlorocyclohexane (β-HCH) was associated with decreased birth weight globally. Mediation analysis was used to explore the metabolic alteration mediating the association between key pesticide exposure and birth outcomes. Results We found that decreased birth weight was significantly associated with increasing levels of mecarbam and β-HCH. We did not find any association between length of gestation and these pesticides. Among pesticides with detection rate more than 50%, BKMR analysis found an overall negative association of mixed pesticides exposure with birth weight, and verified that β-HCH was the key pesticide for such effect. Meta-analysis revealed a significantly negative association between exposure to β-HCH and birth weight. Metabolomics identified three metabolites and five metabolites as significant mediators for the effect of mecarbam and β-HCH, respectively, among which glyceraldehyde and its related glycerolipid metabolism and thyroxine and its related thyroid hormone metabolism were found to be the mostly enriched mediating metabolic pathway. Conclusions Based on the comprehensive pesticide exposome and metabolome wide associational study combined with meta-analysis, we found that prenatal exposure to β-HCH and mecarbam decreased birth weight via disrupting thyroid hormone metabolism and glyceraldehyde metabolism, providing new insights into the toxic effects of exposure to pesticides on birth outcomes.

Background Orofacial clefts (OFCs) are common kind of congenital malformations. The teratogenicity of uranium (U) has been documented in animal study that maternal exposure to U can increase incidence of external malformations including cleft palate. However, there is limited evidence of the association of in utero exposure to U with OFC risk in humans. Objective This study aimed to investigate the association between in utero exposure to U and the risk of OFCs and its subtypes. Method All subjects were from a case-control study in Shanxi Province, northern China. Eighty-four OFC cases and 142 healthy controls were included in this study. We used U concentration in umbilical cord as biomarkers to represent intrauterine exposure, which was detected by inductively coupled plasma mass spectrometry. Unconditional logistic regression was used to investigated the association between U level and the risk of OFCs and its subtypes. Results The median of U concentration in umbilical cord is 0.745 ng/g in case group and 0.455 ng/g in control group. When the U concentration was divided into two categories, high level of U exposure increased the risk of OFCs (OR: 2.08, 95% CI: 1.13–3.86) and its subtype cleft lip with cleft palate (CLP) (OR: 2.72, 95% CI: 1.21–6.14). When divided into three categories, high level of U elevated the risk for OFCs (OR: 2.40, 95% CI: 1.14–5.06) and CLP (OR: 3.04, 95% CI: 1.20–7.74). Meanwhile, a dose-response relationship between the U concentration and the risk of total OFCs (P for trend = 0.009) and CLP (P for trend = 0.007) was found. Conclusion Our study found that in utero exposure to high level of U was associated with increased risk of OFCs and its subtype CLP.

Purpose: The risk and protective factors of Internet gaming disorder (IGD) could vary by individual. The identification of more homogeneous subgroups may lead to better understanding of gaming behaviors and their consequences in adolescents. The purpose of this study was to investigate the prevalence of IGD among the subgroups defined by cluster analysis in adolescents. Methods: A total of 2319 adolescents were enrolled in the Internet User Cohort for Unbiased Recognition of Gaming Disorder in Early Adolescence (iCURE) study at baseline. Self-reported IGD was assessed with a DMS-5 adapted measurement. Smartphone addiction, musculoskeletal discomfort, and dry eye symptoms were evaluated by self-administered questionnaires. Cluster analysis was performed using risk and protective factors of IGD after considering multicollinearity. Results: Three different clusters were identified. Cluster 1 (19.2%) was users with combined potential psychological and social issues. Cluster 2 (32.3%) was users with potential social but no psychological issues. Cluster 3 (45.6%) was users with no potential issues of either a social or psychological nature. Adolescents from both clusters 1 and 2 showed higher degrees of IGD, smartphone addiction, musculoskeletal discomfort, and dry eye symptoms than did those from cluster 3. Also compared with adolescents in cluster 3, those in cluster 1 showed statistically higher risks of IGD (aOR:11.9, 95%CI:7.5–19.9), smartphone addiction (aOR:5.4, 95%CI:4.0–7.2), musculoskeletal discomfort (aOR:2.6, 95%CI:2.1–7.4), and dry eye symptoms (aOR:3.8, 95%CI:3.0–4.9). Those in cluster 2 also showed statistically higher risk of IGD, smartphone addiction, musculoskeletal discomfort, and dry eye symptoms compared with cluster 3 (aOR:4.5, 95%CI:2.8–7.6; aOR:2.8, 95%CI:2.1–3.7; aOR:1.6, 95%CI:1.3–1.9; and aOR:1.9, 95%CI:1.6–2.4, respectively). Conclusions: Clustering based on the risk and preventive factors of IGD may be suitable for determination of high risk of IGD in adolescents. However, we need to confirm the usefulness and clinical application of the classifications by observing their longitudinal changes.

Aims Chronic exposure to nocturnal transportation noise has been linked to cardiovascular disorders with sleep impairment as the main mediator. Here we examined whether nocturnal transportation noise affects the main stress pathways, and whether it relates to changes in the macro and micro structure of sleep. Methods and results Twenty-six young healthy participants (12 women, 24.6 ± 0.7 years, mean ± SE) spent five consecutive 24-h days and one last morning in the laboratory. The first (baseline) and last (recovery) nights comprised a quiet ambient scenario. In-between, four different noise scenarios (low/medium/high intermittent road or rail scenarios with an identical equivalent continuous sound level of 45 dB) were randomly presented during the 8-h nights. Participants felt more annoyed from the transportation noise scenarios compared to the quiet ambient scenario played back during the baseline and recovery nights (F5,117 = 10.2, p < 0.001). Nocturnal transportation noise did not significantly impact polysomnographically assessed sleep macrostructure, blood pressure, nocturnal catecholamine levels and morning cytokine levels. Evening cortisol levels increased after sleeping with highly intermittent road noise compared to baseline (p = 0.002, noise effect: F4,83 = 4.0, p = 0.005), a result related to increased cumulative duration of autonomic arousals during the noise nights (F5,106 = 3.4, p < 0.001; correlation: rpearson = 0.64, p = 0.006). Conclusion Under controlled laboratory conditions, highly intermittent nocturnal road noise exposure at 45 dB increased the cumulative duration of autonomic arousals during sleep and next-day evening cortisol levels. Our results indicate that, without impairing sleep macrostructure, nocturnal transportation noise of 45 dB is a physiological stressor that affects the hypothalamic-pituitary-adrenal axis during the following day in healthy young good sleepers.

Increasing scientific attention on the presence of micro- and nanoplastics (MNPs) in the environments and their potential toxic effects on humans and the ecosystems is evident. Accordingly, the number of publications on this topic has increased substantially from only 5 in 2010 to more than 850 in 2019. Thus, this critical review aimed at providing state-of-the-art information on the existing methods for characterization and detection of MNPs in various matrices, as well as the reported toxic effects of MNPs in both in vivo and in vitro systems, anticipating challenges and providing future needs to improve the current scientific knowledge. We performed a systematic search of recent literature on available methodologies for the characterization/detection of MNPs in different samples, and the summary of such protocols is provided. Also, the existing procedures for in vitro and in vivo toxicity evaluation of MNPs were critically described. The results of our search revealed that quite a great deal of effort had been made to detect, characterize, and quantify the fate and effect of MNPs. However, we are still far from a complete understanding of behaviors of MNPs in the environments and biological systems. Thus, there is a need to advance the existing protocols to improve data accuracy. Besides, more studies that focus on uptake kinetics, accumulation, and biodistribution of MNPs in biological systems are required.

Background Although many studies have established significant associations between short-term air pollution and the risk of getting cardiovascular diseases, there is a lack of evidence based on causal distributed lag modeling. Methods Inverse probability weighting (ipw) propensity score models along with conditional logistic outcome regression models based on a case-crossover study design were applied to get the causal unconstrained distributed (lag0-lag5) as well as cumulative lag effect of short-term exposure to PM2.5/Ozone on hospital admissions of acute myocardial infarction (AMI), congestive heart failure (CHF) and ischemic stroke (IS) among New England Medicare participants during 2000–2012. Effect modification by gender, race, secondary diagnosis of Chronic Obstructive Pulmonary Diseases (COPD) and Diabetes (DM) was explored. Results Each 10 μg/m3 increase in lag0-lag5 cumulative PM2.5 exposure was associated with an increase of 4.3% (95% confidence interval: 2.2%, 6.4%, percentage change) in AMI hospital admission rate, an increase of 3.9% (2.4%, 5.5%) in CHF rate and an increase of 2.6% (0.4%, 4.7%) in IS rate. A weakened lagging effect of PM2.5 from lag0 to lag5 could be observed. No cumulative short-term effect of ozone on CVD was found. People with secondary diagnosis of COPD, diabetes, female gender and black race are sensitive population. Conclusions Based on our causal distributed lag modeling, we found that short-term exposure to an increased ambient PM2.5 level had the potential to induce higher risk of CVD hospitalization in a causal way. More attention should be paid to population of COPD, diabetes, female gender and black race.

The El Niño event is a major large-scale air-sea interaction phenomenon over the tropical Pacific region. Previous studies classified El Niño into three types — canonical El Niño, El Niño Modoki I, and El Niño Modoki II. This research reveals that different types of El Niño present dramatic effects on the interannual variability of sea surface salinity over the central equatorial Indian Ocean in the boreal autumn. The decreasing (increasing) sea surface salinity during the canonical El Niño and the EI Niño Modoki I (the EI Niño Modoki II) events is identified. The salinity budget analysis is performed to identify the dominant factors responsible for the variability of sea surface salinity over the central Indian Ocean. The results indicate that the wind-driven anomalous zonal advection plays an important role in sea surface salinity variability during the El Niño events associated with the forcing from the anomalous Walker circulation over the equatorial Indian Ocean.

Background The linearity of concentration-response (C-R) curve between ambient ozone (O3) concentration and mortality has been controversial. The aim of the present analysis was to examine the C-R curve between O3 concentration and mortality with a causal framework approach. Methods We extracted data of hourly meteorology, hourly O3 concentration and daily non-accidental mortality in Seoul from 2001 to 2009. We divided the dataset into two, odd-number (training set) and even-number years (testing set). Using the training set, we constructed a prediction model from hourly O3 concentration with support vector regression estimating the daily variations of mean O3 concentration caused by sun irradiation, wind speed and direction, controlling temperature, barometric pressure and temporal trend. With this model we predicted variance of daily O3 from the testing set, thus creating an instrumental variable. We analyzed the association between the instrumental variable and daily mortality. We also analyzed the association according to the quartiles of daily mean O3 concentration to examine the linearity of the association. Results The instrumental variable was significantly and negatively associated with daily mortality in the linear model. In the stratified analysis, the negative slope was observed in the lowest quartile and the negative slope of the association diminished as the quartile increased, and the slope became positive over the 3rd quartile (O3 > 23.3 ppb). The interaction between quartiles and instrumental variable was significant (P = 0.0108). Conclusion We observed unequal effect of exposure to ambient O3 concentration on mortality according to the different ranges of daily mean O3 concentration with a causal framework approach.

Xenobiotic metabolism at menopause is an under-investigated topic, albeit women spend one-third of their life in the postmenopausal period. The present study examined the effect of menopause on the in vivo activities of CYP1A2, CYP2A6, xanthine oxidase (XO) and N-acetyltransferase-2 (NAT2) xenobiotic metabolizing enzymes. Enzyme activity was determined in 152 non-smoking volunteers following oral intake of a single dose of 200 mg caffeine and subsequent determination of caffeine metabolite ratios (CMRs) in a 6-h urine sample as follows: CYP1A2: (AFMU+1U+1X)/17U, CYP2A6: 17U/(17U + 17X), XO: 1U/(1U+1X) and NAT2: AFMU/(AFMU+1U+1X). CMRs among groups were analyzed using one-way ANOVA. Significantly lower CYP1A2 and higher CYP2A6 CMRs were observed in postmenopausal compared to premenopausal women and age-matched men. These changes could be attributed to menopause rather than chronological aging since an age-related effect was not observed in premenopausal women or men of any age group. XO CMRs were higher in postmenopausal women and men>50 compared to premenopausal women and men<50, respectively, suggesting an age-related increase in XO activity. No significant alterations were discerned in NAT2 CMRs, in either slow- or rapid-acetylators, indicating that menopause exerts minimal modulation of xenobiotics metabolized by this enzyme. This study provides evidence that the transition to menopause induces significant alterations in xenobiotic-metabolizing enzymes independent of chronological aging suggesting altered metabolism of pharmaceutical and environmental agents.

There are serious concerns associated with greenhouse gases (GHG) fluxes in high latitude ecosystems and how the permafrost thawing may potentially affect the global climate, through the alteration of carbon (C) dioxide (CO2) and methane (CH4) emissions. We performed a meta-analysis of 3002 observations from 104 published studies on CO2 and CH4 fluxes in Siberia (Russian Federation). Siberia is a vast region characterized by a large C-rich permafrost region, which is already degrading due to escalating climate change, and also large wetland areas, also regarded as a source of CH4. GHG fluxes were strongly controlled by location (Western, Central, Eastern, and Far East Siberia), permafrost presence and season. Maximum CO2 fluxes, in the permafrost zone, were observed in Central and Eastern Siberia. In the non-permafrost zone, maximum CO2 fluxes were found in Western Siberia. According to our analyses, CH4 fluxes in the permafrost zone were significantly different in all parts of Siberia. Thus, permafrost has a more profound effect on CH4 than on CO2 flux. The rank order of increase of CH4 emissions among the various Siberian regions is as follows: Central < Eastern < Western < Far East. In the non-permafrost area, CH4 fluxes in Western Siberia are higher than those in the Central part. Soil temperature was the only significant predictor of soil CO2 flux in the permafrost area. CH4 fluxes were well correlated with temperature and soil water content in the permafrost zone, but only dependent on temperature in the non-permafrost area. In this meta-analysis, we established several statistically significant temporal trends of long-term changes of GHG fluxes over three decades (1984–2017): an increasing trend of soil CO2 fluxes in the non-permafrost area of Western Siberia and a declining trend in the non-permafrost area of Central Siberia. There was also a significant increasing trend of CH4 fluxes in the permafrost area of Eastern Siberia, and its decreasing trend in the non-permafrost area of Western Siberia.

In urban settings, one may find (i) lakes that are non-treated (NT) and impacted by recurrent discharges of pollutants and nutrients, and (ii) lakes that, through restoration measures and active management, are treated (T) from external inputs. The optical properties of chromophoric dissolved organic matter (CDOM) have been used to assess the anthropogenic impact on lakes ecology, but their application in comparative assessments of urban lakes has not been attempted. For 2 years, we measured nutrients and CDOM properties in water samples collected from NT and T lakes in the city of Changchun, China. Significant differences in CDOM properties were found between the two types of lakes, and these results were supported by redundancy analysis. The NT lakes were eutrophic while the T lakes were mesotrophic, with mean trophic status index (TSI) of 74.2 and 50.3, respectively. The CDOM absorption coefficient at 350 nm, a (350), was 2-fold higher in NT than in T lakes (6.59 vs 3.21 m-1). In the NT lakes, CDOM components predominantly comprised large molecular weight (MW > 1000-Da) humus-like substances of allochthonous origin, whereas in the T lakes CDOM was dominated by low MW (<1000-Da) substances from autochthonous production. Seasonal fluctuation has a great influence on the CDOM concentration, but a little influence on its molecular composition. The CDOM concentration were higher in summer than in other seasons. Weather conditions (rainfall, temperature) and biophysical processes (biodegradation, photo-bleaching) likely contributed to these variations. We found the water quality of the treated lakes was getting better from 2016 to 2018. In summary, the study results, not only revealed seasonal effects, but most importantly documented the impact of human activities on the characteristics of CDOM in urban lakes. Most specifically, the sharp difference between the lakes in regard to a (350) (2-fold lower in T than in NT lakes) demonstrated the suitability CDOM absorption coefficient as an early indicator of the impact of treatment measures on the hydrochemistry of DOM in urban lakes.

Asian countries face frequent spikes in concentrations of particulate matter smaller than 2.5 μm (PM2.5), which may consist of domestic emissions, transported pollutants from neighboring countries, and secondary aerosol formation (SAF). We aimed to estimate the burden on health in South Korea due to PM2.5 exposure from source countries. We computed the health benefits of meeting air quality guidelines during high pollution periods or spike periods. We used daily mortality counts, PM2.5 concentrations, and primary and secondary contributions to pollutant levels in seven cities and nine provinces in South Korea during 2006–2016. Generalized additive mixed modeling with a Poisson distribution and random effects in 16 regions was used to examine the short-term effects of PM2.5 on mortality. We computed attributable burden due to PM2.5 exposure and the potential benefits of meeting the air quality guidelines set by the World Health Organization (WHO, 25 μg/m3) and the Korea Ministry of Environment (50 and 35 μg/m3 before and after 2015, respectively). A concentration–response curve showed a non-linear relationship between daily mortality counts and PM2.5 levels. The short-term health impacts of PM2.5 were suggested to be 1638 non-accidental deaths in 2016 in South Korea due to daily domestic emissions and pollutants transported from neighboring countries. Of these, 1,509, 995, or 238 deaths could have been prevented if the daily mean PM2.5 concentration had been kept below 25, 35, or 50 μg/m3. After accounting for the contribution of SAF to PM2.5, primary sources of PM2.5 resulted in 258–860 and 26–88 deaths due to pollution transported from China and North Korea, respectively, and 162–538 deaths were due to domestic emissions. Meeting the air quality guidelines of the WHO could have prevented most of these deaths.

Freshwater ecosystems are undergoing extensive human disturbance of dam construction which form large amounts of reservoirs and lead to dramatic changes in hydraulic conditions. Bacterioplankton are key component of aquatic ecosystems. Investigation on their taxonomic compositions and associated functions responded to reservoir operation is essential to understand the ecological consequence of dam construction. In this study, we use the Three Gorges Reservoir as a model system. High-throughput sequencing is used to investigate the bacterioplankton community composition, and the bioinformatic tool of Tax4Fun is applied to predict the potential metabolic functions responded to reservoir impoundment. Results show that the taxonomic communities of bacterioplankton are significantly impacted by impoundment. The dominant group of Actinobacteria which accounts for 17.0%–58.1% of the retrieved sequences significantly increases after impoundment on phylum level. The influences of impoundment appear to be more apparent on order level that the relative abundances of four groups including Frankiales, Sphingomonadales, Sphingobacteriales and SubsectionI of class Cyanobacteria significantly vary after impoundment. In contrast, the predicted functional communities of bacterioplankton remain relatively stable that most of predicted functional categories including methane and nitrogen metabolisms have no significant variation after impoundment. Besides, significant distance decay patterns appear on the taxonomic communities after impoundment rather than the predicted functional communities. The environmental variables show significant impacts on the taxonomic community rather than predicted functional community, whereas the spatial variables have no effect on both taxonomic and predicted functional communities. In general, the taxonomic and predicted functional communities of bacterioplankton exhibit divergent responses to the impoundment in reservoir.