Water quality is a big concern for the humankind as it is the most important natural resource. However, the non-controlled growth of rural and urban areas in rapidly developed countries such as India is affecting water quality. In this research, we pretend to assess and demonstrate the heavy-metal status of three different water bodies of Indus, Beas and Sutlej Rivers and Harike Wetland. Data on water quality from 2013 to 2017 were analyzed through multivariate statistic techniques (cluster analysis – CA – and principal component analysis – PCA) and compared among them using public water pollution indexes. The results of CA and PCA showed that Sutlej River and Harike Wetland are included in the same group, whereas Beas River formed a separate one. This may be due to the high content of Pb, Cu, and Zn in these water bodies as compared with Beas River. The Pb content of all the water bodies exceeded the limit for EPR, BIS and WHO guidelines for drinking water. The heavy-metal pollution index was also applied to the contents of different heavy metals to find which water body is more polluted, and from their results, it was found that Harike Wetland and Sutlej River are critically polluted with heavy metals.

Examination of greenhouse gas emissions is crucial for understanding the global warming. For this reason, identification of the sources of greenhouse gas emissions is crucial. This paper presents a hybrid multi criteria decision making method, which combines analytic hierarchy process and technique for order preference by similarity to ideal solution and compares this method with actual data for identifying the risk priority of sources of greenhouse gas emissions. For this purpose, the historical data of 25-years, for six-greenhouse gas sources and three-greenhouse gases (CO2, CH4, N2O) are considered. Consequently, it was found that while incineration of wastes caused the minimum GHG emissions, energy sector caused the maximum GHG emissions. The results of this paper show that use of this hybrid method is easy and intelligible, and has a good potential for sorting the risk priority of sources of greenhouse gas emissions.

Mountainous areas have become tourism hotspots in recent years, at the same time, some tourism safety issues have been revealed. To study rainstorm hazard prevention and mitigation capabilities, four representative scenic areas in the Qinling Mountains of China were selected as research foci for this study. The similar weight method and the unascertained measure model were used to establish an evaluation index, and the weights of indices at all levels were determined. Rainstorm hazard prevention and mitigation capabilities in the four scenic areas and on defferent slopes were then evaluated quantitatively. The results found that : according to the rainstorm hazard prevention and mitigation capabilities, the rankings of these scenic areas from high to low were Taibai Mountain National Forest Park, Cuihua Mountain National Geopark, Huayang Scenic Area, and Jinsixia National Forest Park. The rainstorm hazard prevention and mitigation capability on the north of the Qinling Mountains were higher than on the south slope, and the difference was relatively large. Rainstorm hazard prevention and mitigation capabilities on the eastern and western Qinling Mountains were more similar. These conclusions could provide a reference for regional rainstorm hazard prevention and mitigation measures, as well as sustainable development.

In this study, the concentrations and health risks of heavy metals (Cu, Pb, Zn, Ni, Co, Cd, and Cr) in indoor dust are investigated in the vicinity of the Xinqiao mining area, Tongling, China. Results indicate that heavy metals except Co were clearly enriched in indoor dust. Especially Cd was extremely enriched, followed by Zn, Cu, and Pb. However, no significant regional differences (p > 0.05) were found in other elemental contents aside from Cu. Statistical analysis revealed that metal elements except Co were presumed to originate primarily from mining activities. Health risk assessment indicated that the hazard quotients and hazard indices of all studied metal elements were less than 1 and thus posed no potential noncancer health risks to adults and children. Moreover, the cancer risks of Ni, Cr, Cd, and Co were within acceptable ranges, implying no cancer risk to local residents; however, the noncarcinogenic risk of Pb and the carcinogenic risk of Cr and Cd warrant close attention.

Quantitative risk assessment (QRA) approaches systematically evaluate the likelihood, impacts, and risk of adverse events. QRA using fault tree analysis (FTA) is based on the assumptions that failure events have crisp probabilities and they are statistically independent. The crisp probabilities of the events are often absent, which leads to data uncertainty. However, the independence assumption leads to model uncertainty. Experts’ knowledge can be utilized to obtain unknown failure data; however, this process itself is subject to different issues such as imprecision, incompleteness, and lack of consensus. For this reason, to minimize the overall uncertainty in QRA, in addition to addressing the uncertainties in the knowledge, it is equally important to combine the opinions of multiple experts and update prior beliefs based on new evidence. In this article, a novel methodology is proposed for QRA by combining fuzzy set theory and evidence theory with Bayesian networks to describe the uncertainties, aggregate experts’ opinions, and update prior probabilities when new evidences become available. Additionally, sensitivity analysis is performed to identify the most critical events in the FTA. The effectiveness of the proposed approach has been demonstrated via application to a practical system.

The distribution, contamination status, and ecological risks of heavy metals in Tahaddart estuary were investigated. 24 surface sediment samples and two cores were collected and analyzed for major (Al and Fe), heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn), and grain size composition. The heavy metals assessment was carried out using different environmental indices. The results indicated that the spatial distribution patterns of Al, Fe, and Zn were mainly determined by the distribution of the finer grained fraction (<63 μm) in the sediment. In contrast, As, Cd, Cr, Cu, Ni, and Pb concentrations were controlled by anthropogenic activities (vehicular traffic from Highway Bridge and thermal power plant). The distribution of heavy metals in sediment cores showed an upward enrichment in heavy metals with high concentration found in the uppermost may related to the increasing in human activities. The pollution indexes confirmed that the Tahaddart estuary sediment was considerably to high contaminated by heavy metals near to different anthropogenic inputs. Similarly, the potential ecological risk index and the biological risk index present 21% probability of toxicity posing potential risk to the aquatic organisms. These results provide basic information that can be used to protect and improve the quality of this ecosystem.

Assessing the impacts of climate change and human activities on runoff is important for planning and managing water resources and for maintaining the integrity of the ecosystem, as well as the normal operation of modern society. In this study, the distribution of precipitation in the Beichuan River basin from 1961 to 2013 is uneven, and we analyzed the impacts of climate change and human activity on the annual and seasonal runoff change during this period. The results showed that runoff was more sensitive to precipitation than the other meteorological factors during the study period, and a 10% increase in precipitation could increase runoff by 17.5%. The annual runoff showed a downward trend during the past 53 years, with an abrupt change point in 1972. We concluded that human activities were mainly responsible for the runoff reduction, and climate change accounted for approximately 30% of the reduction. For the change in seasonal runoff, the dry season runoff had no significant trend, but there was a downward trend in the wet season runoff, with an abrupt change point in 1998. We concluded that human activities were the dominant cause of the reduction in the wet season runoff (88.27%), and climate change accounted for 11.73% of the reduction.

Multielement (48) analysis was carried out of various fish species collected from river Buriganga, the most polluted river in Bangladesh to assess human health risk by toxic elements. Sixteen elements that is, Be, V, Cr, Mn, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Pb, Bi, and U, were taken into account due to their toxicities on human health. Results show that concentrations of elements in various fish species were higher in winter than those in monsoon. Among 16 elements, Mn, Cu, Zn, Cd, Ba, Pb were above Food Safety Guideline in some fishes in winter. THQ and TTHQ/HI values were less than 1 for all fishes in monsoon while THQ and TTHW/HI values were more than 1 for most of fishes in winter. These results suggesting non-carcinogenic health hazard through consumption of contaminated fishes. Only As showed low cancer risk while no cancer risk was observed for other toxic elements in monsoon. In winter, Pb showed only moderate cancer risk for Mystus vittatus (site-7) while for other fishes low cancer risk was found by Pb. It can therefore be concluded that there is human health risk in consuming of fishes collected from river Buriganga especially in winter.

The Huaihe River has suffered increasing pressure from pollutants including metals from anthropogenic activities. In this study, enrichment and fractionation behavior of trace metals were analyzed in sediment samples obtained from fish spawning area of the Huaihe River (Anhui Section) to evaluate the potential ecological risk of trace metals to aquatic organisms. Geochemical indices including enrichment factor and geo-accumulation index as well as mean probable effect concentration quotient and risk assessment code were adopted to assess the contamination degree and potential ecological toxicity. Results showed that the total contents of Cu, Pb, Zn, Cr, Cd, As, and Hg in sediment were 23.1 ± 6.4, 32.3 ± 11.1, 76.8 ± 14.2, 84.6 ± 17.2, 0.2 ± 0.1, 9.0 ± 3.0, and 0.031 ± 0.010 mg/kg, respectively. The indexes EF and Igeo revealed slight accumulation for Pb, Zn, Cr, Cd, and As in some sampling sites. The result of Qm-PEC demonstrated that trace metals in sediment were not toxic to aquatic organisms. Most trace metals appeared to mainly associate with the residual form suggesting lower mobility whereas Cd presented a relative higher exchangeable fraction indicating a great degree of bioavailability. The result of risk assessment code (RAC) evaluation revealed that Cd poses a medium ecological risk for aquatic organisms whereas most of the other trace metals pose low risks.

The present study was conducted to assess the magnitude and health impacts of As in drinking water. Drinking water samples (n = 60) were collected from twenty different sites of Shiekhupura District (Pakistan). Health risk assessment through average daily dose (ADD), hazard indices (HI), hazard quotient (HQ), carcinogenic risk (CR), and cancer indices (CI) for dermal and oral exposure were determined. Results revealed that As concentration ranged from 2 to 900 µg L−1 in water samples, which was significantly greater than the safe limit of As (10 µg L−1) in water. Health risk assessment of As showed that ADD (1.07E−02–9.85E−04), HQ (1.06E+01–9.85E+00), and CR (1.60E−02–9.85E−04) for oral exposure and ADD (1.03E−05–9.69E−06), HQ (1.19E−02–7.96E−03), and CR (1.11E−05–8.98E−05) for dermal exposure which were exceeded the toxic risk index value. Comparison of the two exposure pathways indicated that the oral exposure is much higher risk than the dermal contact. Both values of HI and CI were greater than WHO limit. It is concluded that residents of study area are at higher risk of As induced diseases and carcinogenicity.

Adequate design of control rooms is very important for increasing the reliability of operators working in them. Therefore, it is necessary to choose the best solution for improving the compliance between operators and elements of control room while dealing with problems of illumination, thermal climate and noise. For this purpose we will analyze the impact of execution time of operator's information processing tasks, motor and logical operator's tasks, operator's functional state, workplace risk factors and indoor environment parameters on operator's reliability in control room. Methodological approaches for these five groups are formed and used for experimental research and to determine the level of their quantitative values. Research results are showing the following levels of reliability for specific indicators: reaction time ‐ very good, coefficient of task complexity ‐ optimal, operator's error caused by stress ‐ very good, workplace risk factor ‐ critical and indoor environment ‐ good. Because the functional appropriateness and efficiency in the operator's workplace were inadequate, the following recommendations and solutions were proposed: signaling and control elements should be placed on the central part of the control desk, because due to poor control desk construction, they cause uneven burden on various operator's body parts.

Based on the theory of planned behavior (TPB), this article explains the impact of H7N9 on poultry meat consumption. A sample of 710 respondents from China participated in the current study following an outbreak of avian influenza in 2017. The empirical results of structural equation model indicate that the consumers’ attitude, subjective norm, perceived behavioral control (i.e., the antecedents of the TPB model), as well as their anticipated fear, mediate the relationship between risk perception of H7N9 and poultry consumption intention. Risk perception of H7N9 also influences risk perception of poultry, which has a direct effect on poultry consumption intention. Furthermore, risk perception of poultry is significantly and positively related to anticipated fear and is significantly and negatively related to attitude, which in turn influences the consumption intention. The results confirm the appropriateness of the TPB model and verify that the extended TPB model has good explanatory power in predicting consumers’ intention to consume poultry during a pandemic.

Abstract The goal of identifying hazardous chemicals registered under the Registration, Evaluation, Authorization and restriction of CHemicals (REACH) Regulation and taking appropriate risk management measures relies on robust data registrations. However, the current procedures for European chemical manufacturers and importers to evaluate data under REACH neither support systematic evaluations of data nor transparently communicate these assessments. The aim of this study was to explore how using a data evaluation method with predefined criteria for reliability and establishing principles for assigning reliability categories could contribute to more structured and transparent evaluations under REACH. In total, 20 peer-reviewed studies for 15 substances registered under REACH were selected for an in-depth evaluation of reliability with the SciRAP tool. The results show that using a method for study evaluation, with clear criteria for assessing reliability and assigning studies to reliability categories, contributes to more structured and transparent reliability evaluations. Consequently, it is recommended to implement a method for evaluating data under REACH with predefined criteria and fields for documenting and justifying the assessments to increase consistency of data evaluations and transparency.

Quantification of PM2.5 (particulate matter <2.5 µm) bound heavy metals and their potential health risks were carried out around a cement manufacturing company in Ewekoro, Nigeria. The PM2.5 samples were collected using Environtech gravimetric sampler. A four-staged sequential extraction procedure was used to fractionate PM2.5 bound chromium (Cr), lead (Pb), aluminum (Al), copper (Cu), and silver (Ag), and further analyzed using inductively coupled plasma mass spectrometry. Chemical speciation results reveal bioavailable levels of Pb (4.05 µg/m3), Cr (10.75 µg/m3), Al (16.47 µg/m3), Cu (4.38E-01 µg/m3), and Ag (1.22E-02 µg/m3) in the airborne particulates. Pb and Cr levels exceeded the World Health Organization allowable limit of 0.5 and 2.5E-05 µg/m3, respectively. The labile phases showed strong indication of the presence of Cr and Cu metal. Excess cancer risks exposure for adults, outdoor workers and children were higher than the acceptable risk target level of 1E-06. Non-carcinogenic health risk estimated using hazard quotients (HQs) and hazard indices (HIs) showed ingestion route within the safe level of HI <1 implying no adverse effect while inhalation route exceeded the safe level for all receptors. Enforcement of pollution control by authorized agencies, and screening of greenbelts as sinks for air pollutants is strongly recommended.

The study analyzed changes in surface areas of individual land use types in five administrative regions of Poland in the eastern-most part of the country. Annual time series for the following variables were used: agricultural land, forest land, built-up and urbanized land, and wasteland. The primary objective of the paper was to assess land use changes (LUC) in Eastern Poland in 2002–2016. The paper employed a Mann-Kendall (MK) test and Cox-Stuart (CS) test for monotonic trend and the autoregressive-moving-average (ARMA) model. The deterministic part was selected with the Akaike criterion. The power of the tests was estimated using the Monte Carlo simulation in order to assess their reliability. The results indicate a trend in each of the four series in all the five voivodeships. For forest and built-up land, the trend was upward in each voivodeship. A downward trend was found for the agricultural land and wasteland in all the voivodeships except the Podkarpackie Voivodeship. The results can help regional and local authorities to properly monitor LUC.

The research investigates a novel method to treat acid mine drainage (AMD) using lime and sodium hydroxide modified fly ash (NCFA) with varied dose and time. The analysis showed that pH was raised to 8.24 and approximately 99% of Al, Cd, Cr, Cu, Ni, Pb; 97% of Co, Mn, Zn; 83% of Fe; 35% of Mg; 21% of Na, SO4; and 49% of Cl were removed after 20 min of reaction with 70 gm L−1 dose. The precipitation of these metals as well as sulfate in the form of gypsum on the NCFA surface was detected by X-ray diffraction and field emission scanning electron microscope. The possible mineral phases were identified by PHREEQC geochemical modeling. However, this analysis does not evaluate the hazard of the treated water to aquatic life and human health. Therefore, water quality index (WQI) and hazard index (HI) is proposed in this study to evaluate the risk and identify the optimum dose and time for AMD treatment. These indices confirmed that AMD should be treated with 70 gm L−1 dose of NCFA for 20 min to safeguard human and aquatic life. This study gives a new direction to treat AMD effectively and identify its potential risk to living organisms.

Soil-transmitted helminth (STH) infections caused 4.98 million years live with disability globally in 2014, mostly affecting the poor. When farmers handle excreta for reuse in agriculture, involuntary ingestion of excreta particles is an important infection pathway for STH infections. The aim of this study was to quantify farmers' ingestion of human excreta during common agricultural practices in Vietnam. The weight of excreta that remained on farmers' hands, the weight of excreta that would remain on a farmer' mouth after contact with hand, and the frequency of contact between hand to the mouth by observing farmers while they handled excreta were simulated and quantified. Our findings revealed that farmers are on average exposed 5.16 h to excreta handling per year. Based on this average exposure time, it was estimated that farmers ingest 91 mg of excreta per year (95% CI: 73–110 mg). Our study presents for the first time a robust quantitative estimation of excreta ingestion by farmers during excreta handling in agricultural practices. Hence, this paper makes an important contribution to more robust quantitative microbial risk assessment and health impact assessment related to STH infections and diarrhea in Vietnam and other similar settings where excreta is used as fertilizer.

This study identified the spatial distributions, the sources, and the ecological risks of eight heavy metals in the southern coast of Laizhou Bay, eastern China. For this purpose, a total of 111 topsoil (0∼20 cm) samples were collected from, and analyzed for eight heavy metals (Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn). The average concentrations of Cr, Cu, Hg, Mn, Ni, and Zn were higher than the background values of soils originating from coastal sediment in Shandong Province, indicating the obvious accumulations of these heavy metals in surface soils. Co, Cr, Mn, and Ni mainly came from the parent material, while Cu, Pb, and Zn were affected by both natural sources and human activities. Hg mainly originated from the atmospheric deposition of emissions from coal combustion and the chemical industry. The areas with high contents of heavy metals were consistent with the locations of industrial sites. The geoaccumulation indices and potential ecological risk indices for the heavy metals showed that only a few samples were moderately or strongly polluted by Cu, Pb, Ni, and Zn. However, Hg in the eastern part was at the strong and extreme ecological risk levels, which should receive attention.

We examined the temporal variation of heavy metals in different sexes of three brackish water shrimp species with emphasis on the relationship between Fulton's K condition indices and metal pollution index (MPI). Zn was the most abundant metal followed by Sn, though levels were below the admissible limits (irrespective of gender). Temporal variation of Zn and Pb was significant (p < 0.01). Drier weather conditions influenced Pb accumulation. Temporal variation of Sn was insignificant (p > 0.05), but temporal variation of Hg was significant only in Penaeus monodon (p < 0.0001). However, the relationship between temporal variation of the above-mentioned metals and gender was insignificant except in Penaeus semisulcatus for Pb (p < 0.02) and Sn (p < 0.04) despite no consistent higher bioaccumulation pattern by one particular sex. There were no significant negative correlations between the Fulton's K condition indices and MPI values in the different sexes. MPI values between the two sexes were insignificant. Any differences in the MPI values between the three species were insignificant. Only Penaeus semisulcatus exhibited significant differences (p < 0.022) in Fulton's K condition indices in relation to gender. Fulton's K condition indices are unreliable indicators of metal-induced stress levels in shrimps.

Pharmaceutical pollution has gained attention with the development of analytical technology. The occurrence of 91 pharmaceutically active compounds from variety of drug groups including pain killers, antimicrobials, cardiovascular drugs, hypolipidemic drugs, central nervous system drugs, and stimulants was investigated in Ceyhan River, Turkey. Pharmaceutically active compounds were examined at 9 stations, seasonally during the periods of September 2013–August 2014. For the pharmaceutically active compound analysis, solid phase extraction (SPE) method was used and measured by using liquid chromatography tandem mass spectrometry (LC-MS/MS). Highest measured pharmaceutically active compound concentration was caffeine (4880.00 ng/L). Other high concentrated pharmaceuticals were diazepam (374.00 ng/L), gabapentin (355.00 ng/L), lidocaine (48.70 ng/L), etodolac (47.35 ng/L), metoprolol (43.60 ng/L), carbamazepine (24.25 ng/L), diclofenac (17.60 ng/L), and fluconazole (15.95 ng/L). Carbamazepine and lidocaine were the most frequently detected pharmaceutics in the river water. The results of risk assessment shows that risk quotient values (RQs) is lower than 0.01, except sertraline, which means that most of the detected pharmaceutically active compounds pose no environmental risk to aquatic environment in Ceyhan River. However, it is not possible to give precise information about the effects of all detected pharmaceutically active compounds when they behave together in the aquatic environment.

Abstract The REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) data requirements for mutagenicity and carcinogenicity have been compared to the criteria for classification under Classification, Labelling and Packaging (CLP) and the studies used as key evidence by Committee for Risk Assessment (RAC) in drafting its opinions on the appropriate classification. This comparison revealed that the REACH information requirements will not provide sufficient information to conclude a substance is a Cat 1B mutagen and/or carcinogen. In addition, requiring such information via a substance evaluation under REACH requires a large investment from the Member States and takes years. Classification and labeling is essential in the communication of the hazardous properties of substances and mixtures and is amongst others an important first step in the identification of a substance as a Substance of Very High Concern (SVHC). REACH will hardly generate sufficient information for classification of substances as category 1B for mutagenicity and carcinogenicity. Therefore, indications of very severe hazards of substances are missed and health risks could occur. There are various ways to deal with this problem, however as most of these require adaptation of regulations this will cost considerable time and political will. This study is a first step to raise awareness for the problem and to start a discussion to search for a sustainable solution.

In the Tianjin Port 8·12 explosion, the leakage of enormous amounts of nitrate into the coastal soil-water system threatened the environment and human health. This work aimed to assess the nitrate transport process in unsaturated dredger fills and to conduct an environmental risk assessment to establish guidelines that safeguard groundwater against contamination. The impacts of the bulk density, initial water content, recharge rate, and initial concentration of the nitrate transport process were investigated through an L9 (34) matrix. A field simulation was conducted with Hydrus-1D to explore nitrate transport at the accident site. The results showed the recharge rate and initial water content were the dominant factors affecting the nitrate transport rate and concentration distribution, followed by the initial concentration and bulk density. The contaminant reached the water table in approximately 1.2 years and that approximately 9% of the leaked nitrate entered the aquifer after two years, while the rest of the nitrate remained in the unsaturated zone. The nitrate concentration at a depth of 5.0 m was nearly 1000 mg L–1, which was much higher than the groundwater concentration standard of 30 mg L–1. The soil and groundwater quality warrant special attention due to the excessive nitrate contaminants.

Aboriginal communities of Northeast (NE) India remained in isolation from the mainland and lived in a distinct cultural milieu with the environment. Due to the high degree of exposure and better insight of ground realities, they may have rich traditional knowledge of perception, prediction, and adaptation to climate change. We accessed and illustrated the traditional knowledge on fish and fisheries from the region through participatory rural appraisal (PRA). Our study revealed that ecological and climatic circumstances are maintained through the traditional system of governance and local self-government. Local skills, tools, techniques, wisdom, beliefs and costumes of the aboriginal people act as a shock absorber during disasters and successfully build resilience to climatic hazards. Most of this knowledge was transmitted over successive generations and became a part of living, cultural and religion sustenance. Adaptation strategies at community level fisheries helps in reducing vulnerabilities to extreme weather such as drought, flood and erratic rainfall pattern. Adaptation to climate change in fisheries can decipher through strategies available from fine-scale spatial and grassroots levels. Mainstreaming of climate change adaptation efforts can only be achieved through extensive assessment, research, recognition and promotion of local skills, culture, indigenous knowledge as well as community-based fisheries.

To investigate heavy metal accumulation in mine soils and evaluate health risk through soil digestion, a total of 30 soils were collected from coal mine of Huaibei City, Anhui Province, China, one of the most important coalfields. The mean concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 0.162 ± 0.054, 11.82 ± 3.27, 12.03 ± 5.42, 21.86 ± 7.78, 55.09 ± 12.41, and 41.46 ± 32.07 mg kg–1, respectively. The percentages of heavy metals exceeding background value of soil were 86.7% for Cd, 13.3% for Cu, 16.7% for Ni, 100.0% for Pb, and 20% for Zn. The percentages of heavy metal contents exceeding Grade I of Environmental Quality Standard for soil were 23.3% for Cd, 96.7% for Pb, and 10.0% for Zn. The heavy metal contents did not exceed guideline values according to Grade II of Environmental Quality Standard for soil. Average accessibility of Cd and Pb in the intestinal phase were lower than the gastric phase while a contrary result for Cr, Cu, Ni, and Zn. Both adults and children may not experience non-carcinogenic and carcinogenic health risk through soil digestion.

The main goal of this article was to assess the environmental impact of pollutants from anthropogenic sources (tanning plant) using environmental indicators (Igeo – geoaccumulation index, CF – contamination factor). The assessment was carried out based on the results of total chromium content in soil samples collected in the area of an inoperative tanning plant. Based on the obtained results of total content, significant chromium concentrations were found in the discussed area. All obtained chromium concentrations in the analyzed soil samples exceeded the geochemical background level and the specification limit for group II of soils, i.e. protected areas, defined by a Decree of the Minister of Natural Environment (2016). Based on the obtained results of Igeo and CF, the soils in the analyzed area should be considered highly polluted with chromium.

The volatile organic compounds (VOCs) generated during remediation of contaminated soils in northern China during atypical site management were investigated. After collecting soil and gas samples, VOC concentrations in soil and gas particles were determined. Health risk during remediation of contaminated sites was evaluated using the National Academy of Sciences four guidelines for risk assessment; subsequently, the risk zone of each pollutant for the respiratory exposure pathways was drawn. Our results showed that restoration of VOC-contaminated sites may have serious risks for operating staff with respiratory exposure being the main route of VOC contamination. Regarding respiratory exposure pathways, the greatest noncarcinogenic toxicity was caused by 1,1,2-trichloroethane (noncarcinogenic risk 2.27 E + 03); the maximum carcinogenic toxicity was caused by 1,2-dichloroethane (carcinogenic risk 1.05 E – 01). 1,2-Dichloroethane posed the greatest noncarcinogenic and carcinogenic risks when exposure was via particulate matter inhalation, showing risk of 3.52 E – 04 and 2.23 E – 08, respectively. Regarding skin contact exposure pathways, carbon tetrachloride was the most significant noncarcinogenic risk (2.68 E – 07) and 1,1-dichloroethylene was associated with the maximum carcinogenic risk (4.31 E – 11). Based on the regional risk map of pollutants, higher health risk was determined at a certain distance from the excavation site of the contaminated location in the downwind.

The weight parameter plays an important role in groundwater quality assessment. Importance scale weighting model (ISWM) and entropy weighting model (EWM) are the most common weighing models in conventional literatures. However, ISWM is significantly by the experts’ subjective cognitions, which makes it difficult to generate a unique weight parameter and water quality index (WQI). EWM often neglects the indicator with a serious pollution condition, which makes the assessment result overoptimistic. To solve this problem, this study designs a new health risk weighting model (HRWM). For the pollutant with a higher health risk, a larger weight is assigned; and vice versa. And then, HRWM is applied into the groundwater quality evaluation of Jiamusi City as an illustration. The result shows that HRWM keeps the uniqueness of the weight parameter and the final WQI result, and avoids the overoptimistic phenomenon in assessment result. The groundwater quality of Jiamusi City is under a medium degree of threat or impairment. To further improve the groundwater quality, the environmental managers should adopt more measures to decrease the manganese in the water resources area.

Exposure to disinfection by-products can occur through various pathways such as inhalation, dermal contact, and ingestion for swimmers. In the present study, swimming exposure to disinfection by-products through ingestion and dermal route at the indoor swimming pool was assessed and health risks caused by exposure to these compounds were studied. Water samples were first collected from Eslamshahr (Tehran, Iran) and water quality parameters were analyzed. Then, a multi-pathway model was conducted to assess and estimate the chronic daily intakes (CDI) and lifetime cancer risk (LTCR). The results showed that the mean values of CDIs for chloroform, DCBM, DBCM, and bromoform were 2.12 × 10−6, 7.35 × 10−7, 8.12 × 10−9, and 1.28 × 10−8 mg/kg-d, respectively through ingestion pathways, and 3.95 × 10−5, 1.56 × 10–6, 1.88 × 10–8, and 3.08 × 10−8 mg/kg-d through the dermal pathway, respectively. Also our findings showed that the mean of total LTCR for swimmers was 4.63 × 10−8 and the cancer risks through dermal route were higher than ingestion route. Also, cancer risks of chlorinated compounds were higher to implement a set of strategies in order to improve water treatment of swimming pools.

Mallard Anas platyrhynchos is a numerous and widespread duck of Northern Hemisphere. In some regions, it is an important component of the diet of local inhabitants. It may also serve as an effective bioindicator of pollutions in aquatic environments. In this study, we investigated trace elements concentrations in livers of 23 Mallards shot at fish pond complex during wintering in the Lublin region (SE Poland). The element concentrations followed the pattern: Fe >Mg > Ca > Zn > Cu > Mn > Se > Sr > Cd > Pb > Cr > V > Hg > As > Ni > Sc. Our study revealed lack of sex differences in hepatic element concentrations suggesting similar wintering areas of both sexes. At 8.7% of the examined individuals concentration of Pb was classified as subclinical toxicity or moderate clinical poisoning for Mallards. It indicates serious need for banning of the use of Pb hunting ammunition in those parts of Europe (in that in Poland) where it is still allowed. Such the ban should be established at least in wetlands and waterbodies. Groups of people especially prone to elevated concentration of toxic elements (e.g., pregnant women, children) should avoid consumption of meat originated from wildfowl.

Perfluoroalkyls are stable synthetic chemicals, used in the manufacturing of various industrial products. The release of these compounds in natural ecosystems could interact with living organisms leading to sea food species modification. Laboratory experiments were performed to assess its toxicity on the marine invertebrate Gammarus insensibilis. The LC50 determined by the Regtox package considering several concentrations (5, 10, 15, and 20 mg/L) was about 9.99 mg/L. The biomarkers response was analyzed using adult crustacean treated with 1, 1.6, and 3.1 mg/L of PFOS for 4 days. At the end of the exposure, the activities of acetylcholinesterase (AChE) and superoxyde dismutase (SOD) as well as the malondialdehyde rate (MDA) were measured. The SOD activity was increased at low concentration of PFOS, in contract to the highest one, where it decreased. The AChE activity remains relatively unchangeable during exposure to the tested concentrations, indicating that PFOS is not neurotoxic. The rate of MDA increased after exposure to 1 mg/L of PFOS, which reveals a possible membranous deterioration. The results indicated that oxidative stress and cell damage might be one of the main mechanisms of PFOS toxicity to organisms.

The active mining activities have occurred intensively in Yamal Peninsula, Russia Actic, which may cause hazardous effects on local workers and indigenous Inuts. Geoaccumulation Index (Igeo), pollution Load Index (PLI), transfer factors (TFs), and hazard quotient (HQ) were utilized to the pollution level and human health risk of heavy metals in this region. Twenty samples of soil profile and five lichens were collected in this region. The highest concentrations of heavy metals were discovered in mining areas with a decreasing level of reference sites. Ni and Mn were the dominant metals in all sites. Cd, Ni, and Hg were beyond the regulatory threshold limit values. Igeo shows that Hg was highly or extremely polluted in all sites; Ni was highly moderately to highly polluted only in mining areas. PLI shows soils in all areas were polluted more than one metal. TFs of lichens showed that Cr, Hg, Cu, and Ni were more accumulated in lichens, which may cause bioaccumulation in tundra terrestrial ecosystem. (HQ) presented no health risk for adults as regarding heavy metals, while Ni, Mg, and Hg may cause potential health risks for the local children via soil ingestion.

Soil quality standards used for agricultural land do not fully consider the effect of soil properties on cadmium (Cd) uptake by crops. A pot experiment with six types of soil derived from two typical soil parent materials was conducted to determine the effect of soil properties on the soil Cd fractions and Cd concentration in rice grain. The results of soil Cd fractions obtained by the Community Bureau of Reference sequential extraction revealed significant differences among soil types. Redundancy analysis showed that soil pH was the most influential factor affecting soil Cd fractions for red paddy soil, but soil pH, soil organic matter, and clay content were significant for purple paddy soil. Stepwise multiple linear regression analysis showed that soil clay and soil organic matter were the two most significant variables contributing to soil Cd threshold, explaining 97.8% of the variance. These results suggest that soil clay and organic matter contents should be considered when evaluating the risk of Cd in paddy soil.

Six fish species (Labeo calbasu, Puntius ticto, Notopterus notopterus, Labeo rohita, Channa punctatus, and Aorichthys seenghala) were selected from Dimna Lake, Jamshedpur, India. Metal(loid) (As, Cd, Cr, Cu, Hg, Pb, and Zn) concentrations were assessed in gill, muscle, intestine, liver, and caudal fin of each fish species. The result showed that the concentrations of Cd (2.16–3.87 mg/kg), Cr (2.22–9.97 mg/kg), Hg (0.09–1.99 mg/kg), Pb (12.00–39.65 mg/kg), and Zn (97.20–376.02 mg/kg) were higher than that of previous research and international standard. Industrial discharge, vehicular emission and agricultural run-off were responsible sources of elevated concentration of these metal(loids). Among different organs, highest concentrations were observed in gill, liver and intestine may be attributed to the physiology of organs and their interaction with the environment. Among different fish species, carnivorous and bottom feeders concentrate more metal(loid)s. The potential human health risk due to consumption of fish species was assessed by Target Hazard Quotient (THQ) and Hazard Index (HI) of metal(loid)s. The result showed the value of THQ greater than 1 and the value of HI within 2.7–15.1. These results showed a serious threat (especially due to lead and mercury) to the local population consuming fish from Dimna Lake.

Workers may be exposed to pesticide residues when they enter an area that has been previously treated in order to realize different tasks (e.g., for pruning, cutting, picking, harvesting, pest scouting) or to handle a contaminated crop commodity (e.g., sorting, bundling, packing). A review of the scientific literature on workers exposed to pesticide residues during re-entry tasks provides a comprehensive view of possible exposure routes and a better understanding of the risk assessment context, threshold values, and calculation methodology. Methods assessing the risk to workers health are also reported and discussed. The impact of re-entry activities on health and factors affecting workers exposure are examined. Finally, solutions and mitigation measures aiming to reduce their exposure to pesticide residues are recommended.

The use of Bisphenol A (BPA) has widely been replaced in consumer products by analogs BPB, BPE, BPF, BPS, and BPAF. Recent studies have linked these substitutes to similar adverse health outcomes as BPA, including disruption of endocrine pathways in animal and human studies. We designed a novel MS method, developed specifically for this study, to capture the most relevant BPA alternatives, BPB, BPE, BPF, BPS, BPAF and 4-NP in human blood and urine to quantify potential in utero exposures. To our knowledge, this is the first study to explore in utero exposure to these BPA analogs and the first U.S. study to test for BPA in maternal/fetal pairs. The method was run on 30 paired maternal urine and fetal cord blood samples from mothers undergoing elective Caesarean sections. 90% of mothers and 77% of babies tested positive for at least one BP analog. 83% of mothers tested positive for BPAF, 60% for BPS, 57% for BPB, 17% for BPF and 7% for BPA. 57% of babies tested positive for BPAF and 50% for BPF. BPA and BPB were detected in one cord blood sample each. BPS was not detected in cord blood. BPE was not detected in any fetal cord blood or maternal urine samples. These findings demonstrate the pervasiveness of some BP analogs in pregnant women and their babies at birth.

The Reference Dose (RfD) and Reference Concentration (RfC) are human health reference values (RfVs) representing exposure concentrations at or below which there is presumed to be little risk of adverse effects in the general human population. The 2009 National Research Council report Science and Decisions recommended redefining RfVs as "a risk-specific dose (for example, the dose associated with a 1 in 100,000 risk of a particular end point)." Distributions representing variability in human response to environmental contaminant exposures are critical for deriving risk-specific doses. Existing distributions estimating the extent of human toxicokinetic and toxicodynamic variability are based largely on controlled human exposure studies of pharmaceuticals. New data and methods have been developed that are designed to improve estimation of the quantitative variability in human response to environmental chemical exposures. Categories of research with potential to provide new database useful for developing updated human variability distributions include controlled human experiments, human epidemiology, animal models of genetic variability, in vitro estimates of toxicodynamic variability, and in vitro-based models of toxicokinetic variability. In vitro approaches, with further development including studies of different cell types and endpoints, and approaches to incorporate non-genetic sources of variability, appear to provide the greatest opportunity for substantial near-term advances.

The statistical analysis of cancer bioassay data has historically depended on the pathological determination of the experimental animal's cause of death. The poly-k statistical test has provided a method of statistical analysis of animal bioassay data without the need for cause of death information. The test has been shown to have good statistical properties in the typical 2-year cancer bioassay. However, while the poly-k test has been applied to chronic lifetime animal studies, it has not been formally evaluated with respect to the operating characteristics of this statistical test when applied to such studies. Thus, our objective is to assess the performance of the poly-k test for lifetime studies and to make comparisons with other tests. We observed in one recent lifetime study of the gasoline additive MTBE that the application of the poly-k test was not statistically robust. Simulation studies were subsequently conducted for a limited number of scenarios of lifetime cancer bioassays. These simulations showed that the poly-k test is not statistically robust for testing effect of increasing dose in some lifetime cancer studies.

Animal models play an important role in understanding the mechanisms of bacterial pathogenesis. Here we review recent studies of Salmonella infection in various animal models. Although mice are a classic animal model for Salmonella, mice do not normally get diarrhea, raising the question of how well the model represents normal human infection. However, pretreatment of mice with oral streptomycin, which apparently reduces the normal microbiota, leads to an inflammatory diarrheal response upon oral infection with Salmonella. This has led to a re-evaluation of the role of various Salmonella virulence factors in colonization of the intestine and induction of diarrhea. Indeed, it is now clear that Salmonella purposefully induces inflammation, which leads to the production of both carbon sources and terminal electron acceptors by the host that allow Salmonella to outgrow the normal intestinal microbiota. Overall use of this modified mouse model provides a more nuanced understanding of Salmonella intestinal infection in the context of the microbiota with implications for the ability to predict human risk.

Arsenic, a known human carcinogen, occurs naturally in groundwater in New Jersey and many other states and countries. A number of municipalities in the Piedmont, Highlands, and Valley and Ridge Physiographic Provinces of New Jersey have a high proportion of wells that exceed the New Jersey maximum contaminant level (MCL) of 5 µg/L. Hopewell Township, located in Mercer County and the Piedmont Province, has a progressive local ordinance which requires the installation of dual-tank, point-of-entry treatment systems on affected wells.Thisprovided a unique study opportunity. Of the 55 homes with dual-tank POE treatment systems recruited into this study, 51 homes (93%) had arsenic levels under the MCL at the kitchen sink, regardless of years in service and/or maintenance schedule adherence. Based on the study participants' water consumption and arsenic concentrations, we estimate that Hopewell's arsenic water treatment ordinance, requiring POE dual-tank arsenic treatment, reduced the incidence of excess lifetime (70-year) bladder and lung cancers from 121 (1.7 cancer cases/year) to 16 (0.2 cancer cases/year) preventing 105 lifetime cancer cases (1.5 cases/year). Because the high risk of cancer from arsenic can be mitigated with effective arsenic water treatment systems, this ordinance should be considered a model for other municipalities.

Environmental tobacco smoke (ETS) is estimated to be a significant contributor to in-vehicle human exposure to fine particulate matter of 2.5 µm or smaller (PM(2.5)). A critical assessment was conducted of a mass balance model for estimating PM(2.5) concentration with smoking in a motor vehicle. Recommendations for the range of inputs to the mass-balance model are given based on literature review. Sensitivity analysis was used to determine which inputs should be prioritized for data collection. Air exchange rate (ACH) and the deposition rate have wider relative ranges of variation than other inputs, representing inter-individual variability in operations, and inter-vehicle variability in performance, respectively. Cigarette smoking and emission rates, and vehicle interior volume, are also key inputs. The in-vehicle ETS mass balance model was incorporated into the Stochastic Human Exposure and Dose Simulation for Particulate Matter (SHEDS-PM) model to quantify the potential magnitude and variability of in-vehicle exposures to ETS. The in-vehicle exposure also takes into account near-road incremental PM(2.5) concentration from on-road emissions. Results of probabilistic study indicate that ETS is a key contributor to the in-vehicle average and high-end exposure. Factors that mitigate in-vehicle ambient PM(2.5) exposure lead to higher in-vehicle ETS exposure, and vice versa.

In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility re-use and re-entry could require hours to multiple days. While timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical release. What follows is the second of a two-part analysis identifying key considerations, critical information and decision criteria to facilitate post-attack and post-decontamination consequence management activities. Decision criteria analysis presented here provides first-time, open-literature documentation of multi-pathway, health-based remediation exposure guidelines for selected toxic industrial compounds, chemical warfare agents, and agent degradation products for pre-planning application in anticipation of a chemical terrorist attack. Guideline values are provided for inhalation and direct ocular vapor exposure routes as well as percutaneous vapor, surface contact, and ingestion. Target populations include various employees as well as transit passengers. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination.

In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility reuse and re-entry could require hours to multiple days. While restoration timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical terrorist release. What follows is the first of a two-part analysis identifying key considerations, critical information, and decision criteria to facilitate post-attack and post-decontamination consequence management activities. A conceptual site model and human health-based exposure guidelines are developed and reported as an aid to site-specific pre-planning in the current absence of U.S. state or Federal values designated as compound-specific remediation or re-entry concentrations, and to safely expedite facility recovery to full operational status. Chemicals of concern include chemical warfare nerve and vesicant agents and the toxic industrial compounds phosgene, hydrogen cyanide, and cyanogen chloride. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination.

A comprehensive, quantitative risk assessment is presented of the toxicological risks from buried Exxon Valdez subsurface oil residues (SSOR) to a subpopulation of sea otters (Enhydra lutris) at Northern Knight Island (NKI) in Prince William Sound, Alaska, as it has been asserted that this subpopulation of sea otters may be experiencing adverse effects from the SSOR. The central questions in this study are: could the risk to NKI sea otters from exposure to polycyclic aromatic hydrocarbons (PAHs) in SSOR, as characterized in 2001-2003, result in individual health effects, and, if so, could that exposure cause subpopulation-level effects? We follow the U.S. Environmental Protection Agency (USEPA) risk paradigm by: (a) identifying potential routes of exposure to PAHs from SSOR; (b) developing a quantitative simulation model of exposures using the best available scientific information; (c) developing scenarios based on calculated probabilities of sea otter exposures to SSOR; (d) simulating exposures for 500,000 modeled sea otters and extracting the 99.9% quantile most highly exposed individuals; and (e) comparing projected exposures to chronic toxicity reference values. Results indicate that, even under conservative assumptions in the model, maximum-exposed sea otters would not receive a dose of PAHs sufficient to cause any health effects; consequently, no plausible toxicological risk exists from SSOR to the sea otter subpopulation at NKI.

Prince William Sound (PWS) is a semi-enclosed fjord estuary on the coast of Alaska adjoining the northern Gulf of Alaska (GOA). PWS is highly productive and diverse, with primary productivity strongly coupled to nutrient dynamics driven by variability in the climate and oceanography of the GOA and North Pacific Ocean. The pelagic and nearshore primary productivity supports a complex and diverse trophic structure, including large populations of forage and large fish that support many species of marine birds and mammals. High intra-annual, inter-annual, and interdecadal variability in climatic and oceanographic processes as drives high variability in the biological populations. A risk-based conceptual ecosystem model (CEM) is presented describing the natural processes, anthropogenic drivers, and resultant stressors that affect PWS, including stressors caused by the Great Alaska Earthquake of 1964 and the Exxon Valdez oil spill of 1989. A trophodynamic model incorporating PWS valued ecosystem components is integrated into the CEM. By representing the relative strengths of driver/stressors/effects, the CEM graphically demonstrates the fundamental dynamics of the PWS ecosystem, the natural forces that control the ecological condition of the Sound, and the relative contribution of natural processes and human activities to the health of the ecosystem. The CEM illustrates the dominance of natural processes in shaping the structure and functioning of the GOA and PWS ecosystems.

Phthalates are known reproductive and developmental toxicants in experimental animals. However, in humans, there are few data on the exposure of pregnant women that can be used to assess the potential developmental exposure experienced by the fetus. We measured several phthalate metabolites in maternal urine, maternal serum, and cord serum samples collected at the time of delivery from 150 pregnant women from central New Jersey. The urinary concentrations of most metabolites were comparable to or less than among the U.S. general population, except for mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), three metabolites of di(2-ethylhexyl) phthalate (DEHP). The median urinary concentrations of MEHHP (109 mug/l) and MEOHP (95.1 mug/l) were more than 5 times their population-based concentrations, whereas the median urinary concentration of MEHP was more than 20 times higher. High concentration of MEHP may indicate a recent exposure to the parent chemical DEHP in the hospital shortly before the collection of the samples. Calculation of daily intakes using the urinary biomarker data reveals that none of the pregnant women tested had integrated exposures to DEHP greater than the Agency for Toxic Substances and Disease Registry's minimal risk levels (MRLs chronic 60, intermediate 100 mug/kg/day). No abnormal birth outcomes (e .g., birth weight, Apgar Score, and gestational age) were noted in those newborns whose mothers had relatively greater exposure to DEHP during the perinatal period than others in this study. Significantly greater concentrations and detection frequencies in maternal urine than in maternal serum and cord serum suggest that the urinary concentrations of the phthalate metabolites may be more reliable biomarkers of exposure than their concentrations in other biological specimens.

Organophosphate pesticide (OPPs) concentrations in artesian wells located in Thai agricultural and non-agricultural communities were studied during both wet and dry seasons. A total of 100 water samples were collected and subjects were asked to complete a survey. Gas chromatography flame photometric detector was used for OPP analysis. The average OPP concentration in the agricultural communities (0.085 and 0.418 microg/l in dry and wet season) was higher than in the non-agricultural communities (0.004 microg/l in both seasons). Ingestion of OPPs in contaminated water in the agricultural communities were estimated to be 0.187 and 0.919 microg/day during the dry and wet seasons, respectively, and 0.008 microg/day during both seasons in the non-agricultural communities. Agricultural communities were exposed to pesticide residues under the oral chronic reference dose. This study suggests that people in agricultural communities may be exposed to significantly greater levels of pesticides than non-agricultural populations during the dry and wet seasons (p < .001, .001).

Residents of environmental justice (EJ) communities may bear a disproportionate burden of environmental health risk, and often face additional burdens from social determinants of health. Accounting for cumulative risk should include measures of risk from both environmental sources and social determinants. This study sought to better understand cumulative health risk from both social and environmental sources in a disadvantaged community in Texas. Key outcomes were determining what data are currently available for this assessment, clarifying data needs, identifying data gaps, and considering how those gaps could be filled. Analyses suggested that the traditionally defined EJ community in Port Arthur may have a lower environmental risk from air toxics than the rest of the City of Port Arthur (although the entire city has a higher risk than the average for the state), but may have a larger burden from social determinants of health. However, the results should be interpreted in light of the availability of data, the definitions of community boundaries, and the areal unit utilized. Continued focus on environmental justice communities and the cumulative risks faced by their residents is critical to protecting these residents and, ultimately, moving towards a more equitable distribution and acceptable level of risk throughout society.

The Exxon Valdez oil spill occurred more than two decades ago, and the Prince William Sound ecosystem has essentially recovered. Nevertheless, discussion continues on whether or not localized effects persist on sea otters (Enhydra lutris) at northern Knight Island (NKI) and, if so, what are the associated attributable risks. A recent study estimated new rates of sea otter encounters with subsurface oil residues (SSOR) from the oil spill. We previously demonstrated that a potential pathway existed for exposures to polycyclic aromatic hydrocarbons (PAHs) and conducted a quantitative ecological risk assessment using an individual-based model that simulated this and other plausible exposure pathways. Here we quantitatively update the potential for this exposure pathway to constitute an ongoing risk to sea otters using the new estimates of SSOR encounters. Our conservative model predicted that the assimilated doses of PAHs to the 1-in-1000th most-exposed sea otters would remain 1-2 orders of magnitude below the chronic effects thresholds. We re-examine the baseline estimates, post-spill surveys, recovery status, and attributable risks for this subpopulation. We conclude that the new estimated frequencies of encountering SSOR do not constitute a plausible risk for sea otters at NKI and these sea otters have fully recovered from the oil spill.

We reported in 2003 that exposure to metals on laundered shop towels (LSTs) could exceed toxicity criteria. New data from LSTs used by workers in North America document the continued presence of metals in freshly laundered towels. We assessed potential exposure to metals based on concentrations of metals on the LSTs, estimates of LST usage by employees, and the transfer of metals from LST-to-hand, hand-to-mouth, and LST-to-lip, under average- or high-exposure scenarios. Exposure estimates were compared to toxicity criteria. Under an average-exposure scenario (excluding metals' data outliers), exceedances of the California Environmental Protection Agency, U.S. Environmental Protection Agency, and the Agency for Toxic Substances and Disease Registry toxicity criteria may occur for aluminum, cadmium, cobalt, copper, iron, and lead. Calculated intakes for these metals were up to more than 400-fold higher (lead) than their respective toxicity criterion. For the high-exposure scenario, additional exceedances may occur, and high-exposure intakes were up to 1,170-fold higher (lead) than their respective toxicity criterion. A sensitivity analysis indicated that alternate plausible assumptions could increase or decrease the magnitude of exceedances, but were unlikely to eliminate certain exceedances, particularly for lead.

The European honey bee (Apis mellifera) is a highly valuable, semi-free-ranging managed agricultural species. While the number of managed hives has been increasing, declines in overwinter survival, and the onset of colony collapse disorder in 2006, precipitated a large amount of research on bees' health in an effort to isolate the causative factors. A workshop was convened during which bee experts were introduced to a formal causal analysis approach to compare 39 candidate causes against specified criteria to evaluate their relationship to the reduced overwinter survivability observed since 2006 of commercial bees used in the California almond industry. Candidate causes were categorized as probable, possible, or unlikely; several candidate causes were categorized as indeterminate due to lack of information. Due to time limitations, a full causal analysis was not completed at the workshop. In this article, examples are provided to illustrate the process and provide preliminary findings, using three candidate causes. Varroa mites plus viruses were judged to be a "probable cause" of the reduced survival, while nutrient deficiency was judged to be a "possible cause." Neonicotinoid pesticides were judged to be "unlikely" as the sole cause of this reduced survival, although they could possibly be a contributing factor.

Harlequin Ducks (Histrionicus histrionicus) were adversely affected by the Exxon Valdez oil spill (EVOS) in Prince William Sound (PWS), Alaska, and some have suggested effects continue two decades later. We present an ecological risk assessment evaluating quantitatively whether PWS seaducks continue to be at-risk from polycyclic aromatic hydrocarbons (PAHs) in residual Exxon Valdez oil. Potential pathways for PAH exposures are identified for initially oiled and never-oiled reference sites. Some potential pathways are implausible (e.g., a seaduck excavating subsurface oil residues), whereas other pathways warrant quantification. We used data on PAH concentrations in PWS prey species, sediments, and seawater collected during 2001-2008 to develop a stochastic individual-based model projecting assimilated doses to seaducks. We simulated exposures to 500,000 individuals in each of eight age/gender classes, capturing the variability within a population of seaducks living in PWS. Doses to the maximum-exposed individuals are ∼400-4,000 times lower than chronic toxicity reference values established using USEPA protocols for seaducks. These exposures are so low that no individual-level effects are plausible, even within a simulated population that is orders-of-magnitude larger than exists in PWS. We conclude that toxicological risks to PWS seaducks from residual Exxon Valdez oil two decades later are essentially non-existent.

During 1985-1990, two groups of killer whales in Prince William Sound, Alaska, experienced unusually high rates of mortality, while seven others did not. Those affected were AB pod, part of the southern Alaska population of resident (fish-eating) killer whales, and the AT1 transient (marine mammal-eating) group, a very small, reproductively isolated population that last reproduced in 1984. In 1985-1986, several AB pod members were shot by fishermen defending their catch from depredation, which explains some of the deaths. Understanding the other deaths is complicated by the Exxon Valdez oil spill (March 1989) and uncertainties about the causes and times of the deaths. For AB pod, possible factors involved in the post-spill mortalities are delayed effects of bullet wounds, continued shooting, oil exposure, and consequences of being orphaned. For the AT1 group, possible factors are oil exposure, small population size, old age, and high-contaminant burdens. An analysis of possible effects of inhalation of volatile organic compounds, contact with the oil slick, and ingestion of oil with water or prey did not reveal route(s) of exposure that could explain the mortalities. The cause(s) of the killer whale deaths recorded following the oil spill remain uncertain.

Styrene was listed as "reasonably anticipated to be a human carcinogen" in the twelfth edition of the National Toxicology Program's Report on Carcinogens based on what we contend are erroneous findings of limited evidence of carcinogenicity in humans, sufficient evidence of carcinogenicity in experimental animals, and supporting mechanistic data. The epidemiology studies show no consistent increased incidence of, or mortality from, any type of cancer. In animal studies, increased incidence rates of mostly benign tumors have been observed only in certain strains of one species (mice) and at one tissue site (lung). The lack of concordance of tumor incidence and tumor type among animals (even within the same species) and humans indicates that there has been no particular cancer consistently observed among all available studies. The only plausible mechanism for styrene-induced carcinogenesis-a non-genotoxic mode of action that is specific to the mouse lung-is not relevant to humans. As a whole, the evidence does not support the characterization of styrene as "reasonably anticipated to be a human carcinogen," and styrene should not be listed in the Report on Carcinogens.

Food allergies are emerging health risks in much of the Western world, and some evidence suggests prevalence is increasing. Despite lacking scientific consensus around prevalence and management, policies and regulations are being implemented in public spaces (e.g., schools). These policies have been criticized as extreme in the literature, in the media, and by the non-allergic population. Backlash appears to be resulting from different perceptions of risk between different groups. This article uses a recently assembled national dataset (n = 3,666) to explore how Canadians perceive the risks of food allergy. Analyses revealed that almost 20% self-report having an allergic person in the household, while the average respondent estimated the prevalence of food allergies in Canada to be 30%. Both of these measures overestimate the true clinically defined prevalence (7.5%), indicating an inflated public understanding of the risks of food allergies. Seventy percent reported food allergies to be substantial risks to the Canadian population. Multivariate logistic regression models revealed important determinants of risk perception including demographic, experience-based, attitudinal, and regional predictors. Results are discussed in terms of understanding emerging health risks in the post-industrial era, and implications for both policy and risk communication.

The U.S. National Toxicology Program (NTP) conducted 2-year bioassays of commercial grade toluene diisocyanate (TDI) (80% 2,4-TDI and 20% 2,6-TDI) and 2,4-toluene diamine (TDA) and concluded that both were carcinogenic in rodents. In the TDI study, there was an unproven but likely formation of TDA either because of flawed test-substance handling and storage conditions and/or the atypical exposure conditions employed. Although the carcinogenic responses in both studies were qualitatively similar, several statistical analyses were performed to substantiate this possibility more rigorously. Seven different statistical approaches combine to yield a robust and consistent conclusion that, if only a small fraction (approximately 5%) of the dose of TDI were hydrolyzed to TDA in the TDI study, then that would be sufficient to explain the observed carcinogenic responses in the TDI study.

Humans are potentially exposed to phthalate esters (PEs) through ingestion, inhalation, and dermal contact. Studies quantifying exposure to PEs include "biomarker studies" and "indirect studies." Biomarker studies use measurements of PE metabolites in urine to back-calculate exposure to the parent diester, while indirect studies use the concentration of the PE in each medium of exposure and the rate of intake of that medium to quantify intake of the PE. In this review, exposure estimates from biomarker and indirect studies are compiled and compared for seven PEs to determine if there are regional differences and if there is a preferred approach. The indirect and biomarker methods generally agree with each other within an order of magnitude and discrepancies are explained by difficulties in accounting for use of consumer products, uncertainty concerning absorption, regional differences, and temporal changes. No single method is preferred for estimating intake of all PEs; it is suggested that biomarker estimates be used for low molecular weight PEs for which it is difficult to quantify all sources of exposure and either indirect or biomarker methods be used for higher molecular weight PEs. The indirect methods are useful in identifying sources of exposure while the biomarker methods quantify exposure.