Environmental Chemical Risk Research Articles

Development of a novel scheme for rapid screening for environmental micropollutants in emergency situations (REPE) and its application for comprehensive analysis of tsunami sediments deposited by the great east Japan earthquake

The tsunami triggered by the Great East Japan Earthquake of March 2011, the strongest quake ever recorded in Japan, deposited tsunami sediments along the coastline of the affected area. Because the sediments contained a wide variety of hazardous chemicals, including organic micropollutants, a method for rapidly evaluating the environmental and human health risks of such chemicals is necessary. For this purpose, we propose a novel three-step scheme designated “rapid screening for environmental micropollutants in emergency situations (REPE)”. In the first step, samples are subjected to target screening analysis using an automated identification and quantification system (TSA-AIQS) involving gas chromatography mass spectrometry (GC-MS). In the second step, the chemicals detected by TSA-AIQS analysis are quantified precisely by conventional target analysis. The third step is risk assessment of the target chemicals. TSA-AIQS analysis of the tsunami sediments detected 63 substances, including polycyclic aromatic hydrocarbons (both native and alkylated PAHs) at high concentrations. These PAHs were precisely quantified by target analysis, and the concentrations were used to assess the health risks posed by oral intake, which were found to be negligible. Our results suggest that the REPE scheme will be useful for rapid, comprehensive screening and risk assessment in emergency situations.

Establishment of a high-sensitivity reporter system in mammalian cells for detecting juvenoids using juvenile hormone receptors of Daphnia pulex.

Environmental waters are polluted by various chemicals originating from human activities. Recently, the environmental risk of juvenile hormones (JHs) to aquatic microcrustaceans has been recognized by risk assessors and researchers. JH is a major arthropod hormone that regulates molting and reproduction and has analogs that have been used as insect growth regulators. JHs are known to disturb the sex determination system of Daphnia, which is a keystone animal in limnetic ecosystems and is not the target of extermination. To assess the risk of contaminant chemicals and to protect biodiversity, reliable methods for detecting such chemicals are essential. In this study, we attempted to establish a practical in vitro reporter assay system for detecting chemicals with JH activity. Using a newly constructed reporter vector (modified from the JH response element of Tribolium castaneum Krüppel homolog 1, which is a major JH responsive gene in insects), strong JH-dependent transcriptional activity (>40-fold activation) was found in Chinese hamster ovary cells that express JH receptors of Daphnia pulex. Dose-response analysis conducted on several JH and non-JH chemicals revealed that the established reporter assay system has strict specificity to JH chemicals, and the half maximum effective concentration (EC50 ) was between 10-7 and 10-9 m. These results suggest that the new system is a rapid and economical method for assessing the environmental risk of JH-active chemicals.

An Extract Purified from the Mycelium of a Tomato Wilt-Controlling Strain of Fusarium sambucinum Can Protect Wheat against Fusarium and Common Root Rots.

An approach to manage seed-transmitted Fusarium crown-foot-root rot (FCR, Fusarium spp.) and common root rot (CRR, Bipolaris sorokiniana) on wheat, avoiding environmental risks of chemicals, is seed treatments with microbial metabolites. F. sambucinum strain FS-94 that induces resistance to tomato wilt was shown by this study to be a source of non-fungitoxic wheat-protecting metabolites, which were contained in a mycelium extract purified by gel-chromatography and ultrafiltration. Plant-protecting effect of the purified mycelial extract (PME) was demonstrated in vegetation experiments using a rolled-towel assay and by small-plot field trials. To elucidate mechanisms putatively underlying PME protective activity, tests with cultured Triticum aestivum and T. kiharae cells, particularly the extracellular alkalinization assay, as well as gene expression analysis in germinated wheat seeds were used. Pre-inoculation treatments of seeds with PME significantly decreased the incidence (from 30 to 40%) and severity (from 37 to 50%) of root rots on seedlings without any inhibition of the seed germination and potentiation of deoxynivalenol (DON), DON monoacetylated derivatives and zearalenon production in FCR agents. In vegetation experiments, reductions in the DON production were observed with doses of 0.5 and 1 mg/mL of PME. Pre-sowing PME application on seeds of two spring wheat cultivars naturally infected with FCR and CRR provided the mitigation of both diseases under field conditions during four growing seasons (2013–2016). PME-induced ion exchange response in cultured wheat cells, their increased survivability, and up-regulated expression of some defensins’ genes in PME-exposed seedlings allow the suggestion of the plant-mediated character of disease-controlling effect observed in field.

Conditional Toxicity Value (CTV) Predictor: An In Silico Approach for Generating Quantitative Risk Estimates for Chemicals.

Background:Human health assessments synthesize human, animal, and mechanistic data to produce toxicity values that are key inputs to risk-based decision making. Traditional assessments are data-, time-, and resource-intensive, and they cannot be developed for most environmental chemicals owing to a lack of appropriate data.Objectives:As recommended by the National Research Council, we propose a solution for predicting toxicity values for data-poor chemicals through development of quantitative structure–activity relationship (QSAR) models.Methods:We used a comprehensive database of chemicals with existing regulatory toxicity values from U.S. federal and state agencies to develop quantitative QSAR models. We compared QSAR-based model predictions to those based on high-throughput screening (HTS) assays.Results:QSAR models for noncancer threshold-based values and cancer slope factors had cross-validation-based of 0.25–0.45, mean model errors of 0.70–1.11 units, and applicability domains covering of environmental chemicals. Toxicity values predicted from QSAR models developed in this study were more accurate and precise than those based on HTS assays or mean-based predictions. A publicly accessible web interface to make predictions for any chemical of interest is available at http://toxvalue.org.Conclusions:An in silico tool that can predict toxicity values with an uncertainty of an order of magnitude or less can be used to quickly and quantitatively assess risks of environmental chemicals when traditional toxicity data or human health assessments are unavailable. This tool can fill a critical gap in the risk assessment and management of data-poor chemicals. https://doi.org/10.1289/EHP2998

Comparison of substitution status of chemical substances under REACH and OSPAR legislation

The EU REACH Regulation (Registration, Evaluation, and Authorisation of Chemicals) was adopted in 2006 to regulate the human and environmental risks of chemicals in all applications and will be implemented by 2018. So far, the environmental risks from offshore chemicals in the North Sea have been regulated by the Harmonised Mandatory Control Scheme developed by OSPAR. Both the OSPAR scheme and REACH identify hazardous substances based on their persistence, bioaccumulation potential and toxicity (PBT), but the mechanisms employed are different.As a result, carrying out OSPAR's declared aim of harmonising with REACH where possible will not be straightforward.The presented research compared the assessment and classification of chemicals used in offshore oil and gas production under OSPAR and REACH. The aim was to establish the extent of commonality in classification between the two regulatory frameworks as well as their specific differences due to the different foci of REACH (human health and environment) and OSPAR (marine environment). These intrinsic differences in the assessment of PBT substances were identified as the main challenge in harmonising the two pieces of legislation. At the same time, the comparison of OSPAR and REACH assessments for offshore chemicals provided insight in the driving factors for observed differences between assessments and highlighted the benefits and need of having targeted legislative frameworks that focus on the protection of specific aspects of the environment.

Study on Risk Assessment Method of Marine Environment for Dangerous Chemicals

With the frequent occurrence of marine dangerous chemicals accidents, it is particularly important to assess the marine environmental risk of hazardous chemicals. In the paper, a qualitative risk assessment method is summarized by analyzing the research status at home and abroad in recent years. The method is mainly applicable to risk assessment of low-risk hazardous chemicals.

A Millifluidic System for Analysis of Daphnia magna Locomotory Responses to Water-born Toxicants

Aquatic toxicity testing in environmental monitoring and chemical risk assessment is critical to assess water quality for human use as well as predict impact of pollutants on ecosystems. In recent years, studies have increasingly focused on the relevance of sub-lethal effects of environmental contaminants. Sub-lethal toxicity endpoints such as behavioural responses are highly integrative and have distinct benefits for assessing water quality because they occur rapidly and thus can be used to sense the presence of toxicants. Our work describes a Lab-on-a-Chip system for the automated analysis of freshwater cladoceran Daphnia magna locomotory responses to water-born toxicants. The design combines a Lab-on-a-Chip system for Daphnia sp. culture under perfusion with time-resolved videomicroscopy and software tracking locomotory activity of multiple specimens. The application of the system to analyse the swimming behaviour of water fleas exposed to different concentrations of water-born toxicants demonstrated that Lab-on-a-Chip devices can become important research tools for behavioural ecotoxicology and water quality biomonitoring.

Chemical monitoring of Swedish coastal waters indicates common exceedances of environmental thresholds, both for individual substances as well as their mixtures

Chemical pollution was monitored and assessed along the Swedish west coast. 62 of 172 analyzed organic chemicals were detected in the water phase of at least one of five monitored sites. A Concentration Addition based screening-level risk assessment indicates that all sites are put at risk from chemical contamination, with total risk quotients between 2 and 9. Only at one site did none of the individual chemicals exceeded its corresponding environmental threshold (PNEC, EQS). The monitoring data thus demonstrate a widespread blanket of diffuse pollution, with no clear trends among sites. Further issues critical for the environmental chemical risk assessment include the challenges to achieve sufficiently low levels of detection, especially for hormones and cypermethrin (a pyrethroid insecticide), the appropriate consideration of non-detects and the limited availability of reliable PNECs and EQS values.

Age at Menopause: Do Chemical Exposures Play a Role?

Age at Menopause: Do Chemical Exposures Play a Role?

Environmental risk assessment of selected organic chemicals based on TOC test and QSAR estimation models

Environmental risks of organic chemicals have been greatly determined by their persistence, bioaccumulation, and toxicity (PBT) and physicochemical properties. Major regulations in different countries and regions identify chemicals according to their bioconcentration factor (BCF) and octanol–water partition coefficient (Kow), which frequently displays a substantial correlation with the sediment sorption coefficient (Koc). Half-life or degradability is crucial for the persistence evaluation of chemicals. Quantitative structure activity relationship (QSAR) estimation models are indispensable for predicting environmental fate and health effects in the absence of field- or laboratory-based data. In this study, 39 chemicals of high concern were chosen for half-life testing based on total organic carbon (TOC) degradation, and two widely accepted and highly used QSAR estimation models (i.e., EPI Suite and PBT Profiler) were adopted for environmental risk evaluation. The experimental results and estimated data, as well as the two model-based results were compared, based on the water solubility, Kow, Koc, BCF and half-life. Environmental risk assessment of the selected compounds was achieved by combining experimental data and estimation models. It was concluded that both EPI Suite and PBT Profiler were fairly accurate in measuring the physicochemical properties and degradation half-lives for water, soil, and sediment. However, the half-lives between the experimental and the estimated results were still not absolutely consistent. This suggests deficiencies of the prediction models in some ways, and the necessity to combine the experimental data and predicted results for the evaluation of environmental fate and risks of pollutants.

Application of radial basis function neural network to predict soil sorption partition coefficient using topological descriptors

The soil sorption partition coefficient logKoc is an indispensable parameter that can be used in assessing the environmental risk of organic chemicals. In order to predict soil sorption partition coefficient for different and even unknown compounds in a fast and accurate manner, a radial basis function neural network (RBFNN) model was developed. Eight topological descriptors of 800 organic compounds were used as inputs of the model. These 800 organic compounds were chosen from a large and very diverse data set. Generalized Regression Neural Network (GRNN) was utilized as the function in this neural network model due to its capability to adapt very quickly. Hence, it can be used to predict logKoc for new chemicals, as well. Out of total data set, 560 organic compounds were used for training and 240 to test efficiency of the model. The obtained results indicate that the model performance is very well. The correlation coefficients (R2) for training and test sets were 0.995 and 0.933, respectively. The root-mean square errors (RMSE) were 0.2321 for training set and 0.413 for test set. As the results for both training and test set are extremely satisfactory, the proposed neural network model can be employed not only to predict logKoc of known compounds, but also to be adaptive for prediction of this value precisely for new products that enter the market each year.

Environmental Chemical Assessment in Clinical Practice: Unveiling the Elephant in the Room.

A growing body of evidence suggests chemicals present in air, water, soil, food, building materials and household products are toxicants that contribute to the many chronic diseases typically seen in routine medical practice. Yet, despite calls from numerous organisations to provide clinicians with more training and awareness in environmental health, there are multiple barriers to the clinical assessment of toxic environmental exposures. Recent developments in the fields of systems biology, innovative breakthroughs in biomedical research encompassing the “-omics” fields, and advances in mobile sensing, peer-to-peer networks and big data, provide tools that future clinicians can use to assess environmental chemical exposures in their patients. There is also a need for concerted action at all levels, including actions by individual patients, clinicians, medical educators, regulators, government and non-government organisations, corporations and the wider civil society, to understand the “exposome” and minimise the extent of toxic exposures on current and future generations. Clinical environmental chemical risk assessment may provide a bridge between multiple disciplines that uses new technologies to herald in a new era in personalised medicine that unites clinicians, patients and civil society in the quest to understand and master the links between the environment and human health.

Mesocage collector cavities as nanopockets for remediation and real assessment of carbamate pesticides in aquatic water

Remediation of chemicals such as pesticides in contaminated surface water and ground water is a major global concern because of the increased public awareness of the health risks and environmental risks of such chemicals. For use as a pesticide remediation system, we herein report a scalable, high-yield three-dimensional mesocage collector of micrometric aluminosilica particles with a large cavity of 7.0-nm pocket-like pores and a regular entrance pore. Analysis of the geometrical features of the mesocage collector cavities (MCC) revealed that they had several key characteristics, such as suitable guest accommodation, intermolecular forces, and electrostatic and non-electrostatic interactions. The MCC took up large quantities of pesticides onto the framework surfaces and into the hierarchical pocket-like pores, and the pesticides could subsequently be efficiently recovered from the MCCs, which could then be reused. We used the MCCs to recover pesticides from contaminated tap water and lake water samples, and our results indicate that the MCCs are a potentially effective tool for reducing the environmental burden due to contaminated water.

Systematic reviews: Separating fact from fiction

The volume of scientific literature continues to expand and decision-makers are faced with increasingly unmanageable volumes of evidence to assess. Systematic reviews (SRs) are powerful tools that aim to provide comprehensive, transparent, reproducible and updateable summaries of evidence. SR methods were developed, and have been employed, in healthcare for more than two decades, and they are now widely used across a broad range of topics, including environmental management and social interventions in crime and justice, education, international development, and social welfare. Despite these successes and the increasing acceptance of SR methods as a ‘gold standard’ in evidence-informed policy and practice, misconceptions still remain regarding their applicability. The aim of this article is to separate fact from fiction, addressing twelve common misconceptions that can influence the decision as to whether a SR is the most appropriate method for evidence synthesis for a given topic. Through examples, we illustrate the flexibility of SR methods and demonstrate their suitability for addressing issues on environmental health and chemical risk assessment.

Environmental chemical risk factors for Type 2 diabetes: an update

SUMMARY Increasing evidence suggests a role for environmental chemicals in the promotion of Type 2 diabetes. This review summarizes epidemiologic studies of environmental chemical exposures reported to be associated with Type 2 diabetes and insulin resistance. Chemicals are classified as having moderate, limited and insufficient degrees of evidence in support of a diabetes-promoting effect. Moderate evidence exists for diabetogenic effects of inorganic arsenic and persistent organic pollutants, including organochlorines, dioxins and polychlorinated biphenyls. Limited evidence supports a role for environmental tobacco smoke and ambient air pollution. Insufficient evidence is available regarding the potential effects of bisphenol A, phthalates, organophosphates and pyrethroids; most studies of such short-lived pollutants have been cross-sectional and do not demonstrate causality.

TBBPA induces developmental toxicity, oxidative stress, and apoptosis in embryos and zebrafish larvae (Danio rerio).

Tetrabromobisphenol A (TBBPA) is currently one of the most frequently used brominated flame retardants and can be considered as a high production volume chemical. In this study, zebrafish embryos and larvae served as a biological model to evaluate TBBPA-induced developmental toxicity, oxidative stress, oxidant-associated gene expression, and cell apoptosis. Abnormalities, including hyperemia and pericardial edema, were induced in zebrafish larvae. The results showed that toxicity endpoints such as hatching rate, survival rate, malformation rate, and growth rate had a significant dose-response relationship with TBBPA. Further studies revealed that TBBPA did not alter the enzyme activities of Copper/Zinc Superoxide dismutase (Cu/Zn-SOD), catalase (CAT), and glutathioneperoxidase (GPx) at 0.10 mg/L, but decreased activities following exposure to 0.40, 0.70, and 1.00 mg/L. Despite the significantly decreased gene expression of Cu/Zn-SOD, CAT, and GPx1a in the 1.00 mg/L treatment group, other treatments (0.10, 0.40, 0.70 mg/L) did not alter gene expression. Moreover, Acridine orange staining results showed that apoptotic cells mainly accumulated in the brain, heart, and tail, indicating possible TBBPA-induced brain, cardiac, and blood circulation system impairment in zebrafish embryos and larvae. Histological analysis also showed evidence of obvious heart impairment in TBBPA-treated groups. This study provides new evidence on the developmental toxicity, oxidative stress, and apoptosis of embryos and zebrafish larvae, which is important for the evaluation of environmental toxicity and chemical risk. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1241-1249, 2016.

Evaluating geographically weighted regression models for environmental chemical risk analysis.

In the evaluation of cancer risk related to environmental chemical exposures, the effect of many correlated chemicals on disease is often of interest. The relationship between correlated environmental chemicals and health effects is not always constant across a study area, as exposure levels may change spatially due to various environmental factors. Geographically weighted regression (GWR) has been proposed to model spatially varying effects. However, concerns about collinearity effects, including regression coefficient sign reversal (ie, reversal paradox), may limit the applicability of GWR for environmental chemical risk analysis. A penalized version of GWR, the geographically weighted lasso, has been proposed to remediate the collinearity effects in GWR models. Our focus in this study was on assessing through a simulation study the ability of GWR and GWL to correctly identify spatially varying chemical effects for a mixture of correlated chemicals within a study area. Our results showed that GWR suffered from the reversal paradox, while GWL overpenalized the effects for the chemical most strongly related to the outcome.

Use of multimedia environmental models in chemical exposure assessments

Governments and also the general public are concerned with the environmental risk of chemicals. The chemical authorities from the European Union and other developed countries have emphasized No Data, No Markets. This has repercussions for Chinas industry and economic growth. Hence, China has to focus on the environmental risk management of chemicals rather than hazard management. Exposure assessment is needed for the risk assessment and management of chemicals. Multimedia environmental models are simple and effective tools for exposure assessment. They can be used to estimate the level, distribution and half-residence time of chemicals in the environment, and these models comprehensively describe the environmental fate of chemicals. In this review, the theoretical foundation and development of multimedia environmental models are introduced. The studies on multimedia environmental models used for exposure assessments of chemicals are summarized. And five widely-used environmental exposure assessment tools are compared. In addition, we discuss two opposing trends in model development. Multimedia environmental models have promising potential applications in the environmental risk assessment and management of chemicals.

Higher urinary heavy metal, arsenic, and phthalate concentrations in people with high blood pressure: US NHANES, 2009–2010

Background: A link between environmental chemicals and human health has emerged but not complete in risk factors. This work aimed to study the relationships of different sets of urinary environmental chemical concentrations and risk of high blood pressure (BP) in a national, population-based study. Methods: Data was retrieved from United States National Health and Nutrition Examination Surveys, 2009–2010, including demographics, BP readings and urinary environmental chemical concentrations. Analyses included t-test and survey-weighted logistic regression models. Results: Urinary mercury concentrations were not associated with high BP (OR = 1.19, 95% CI 0.97–1.48, p = 0.095). Urinary cobalt (OR = 1.35, 95% CI 1.01–1.81, p = 0.044), lead (OR = 1.77, 95% CI 1.31–2.38, p = 0.001), antimony (OR = 1.37, 95% CI 1.09–1.72, p = 0.010) and tungsten (OR = 1.52, 95% CI 1.27–1.81, p < 0.001) concentrations were observed to increase the risk of high BP. There are no clear associations between environmental parabens and high BP. The effect of environmental bisphenol A (OR = 1.14, 95% CI 1.00–1.30, p = 0.051) disappeared after additionally adjusting for subsample weighting (OR = 1.12, 95% CI 0.93–1.35, p = 0.225). People with higher urinary mono-2-ethyl-5-carboxypentyl phthalate (OR = 1.26, 95% CI 1.00–1.58, p = 0.051), mono-n-butyl phthalate (OR = 1.19, 95% CI 1.01–1.41, p = 0.042) and mono-n-methyl phthalate metabolites (OR = 1.16, 95% CI 1.03–1.32, p = 0.021) tended to have high BP. Moreover, urinary o-phenyl phenol concentrations (OR = 1.49, 95% CI 1.25–1.77, p < 0.001) and dimethylarsonic acid concentrations (OR = 1.35, 95% CI 1.06–1.73, p = 0.019) were also seen to be associated with high BP. Conclusions: Urinary environmental chemical concentrations were associated with risk of high BP, although the causal effect cannot be established. Elimination of environmental chemicals in humans would need to be continued.

Higher urinary heavy metal, phthalate, and arsenic but not parabens concentrations in people with high blood pressure, U.S. NHANES, 2011-2012.

Link between environmental chemicals and human health has emerged but not been completely examined in risk factors. Therefore, it was aimed to study the relationships of different sets of urinary environmental chemical concentrations and risk of high blood pressure (BP) in a national, population-based study. Data were retrieved from United States National Health and Nutrition Examination Surveys, 2011–2012 including demographics, BP readings, and urinary environmental chemical concentrations. Analyses included chi-square test, t-test and survey-weighted logistic regression modeling. After full adjustment (adjusting for urinary creatinine, age, sex, ethnicity, and body mass index), urinary cesium (OR 1.56, 95%CI 1.11–2.20, P = 0.014), molybden (OR 1.46, 95%CI 1.06–2.01, P = 0.023), manganese (OR 1.42, 95%CI 1.09–1.86, P = 0.012), lead (OR 1.58, 95%CI 1.28–1.96, P < 0.001), tin (OR 1.44, 95%CI 1.25–1.66, P < 0.001), antimony (OR 1.39, 95%CI 1.10–1.77, P = 0.010), and tungsten (OR 1.49, 95%CI 1.25–1.77, P < 0.001) concentrations were observed to be associated with high BP. People with higher urinary mono-2-ethyl-5-carboxypentyl phthalate (OR 1.33, 95%CI 1.00–1.62, P = 0.006), mono-n-butyl phthalate (OR 1.35, 95%CI 1.13–1.62, P = 0.002), mono-2-ethyl-5-hydroxyhexyl (OR 1.25, 95%CI 1.05–1.49, P = 0.014), mono-n-methyl phthalate (OR 1.26, 95%CI 1.07–1.48, P = 0.007), mono-2-ethyl-5-oxohexyl (OR 1.25, 95%CI 1.07–1.48, P = 0.009), and monobenzyl phthalate (OR 1.40, 95%CI 1.15–1.69, P = 0.002) tended to have high BP as well. However, there are no clear associations between environmental parabens and high BP, nor between pesticides and high BP. In addition, trimethylarsine oxide (OR 2.47, 95%CI 1.27–4.81, P = 0.011) and dimethylarsonic acid concentrations (OR 1.42, 95%CI 1.12–1.79, P = 0.006) were seen to be associated with high BP. In sum, urinary heavy metal, phthalate, and arsenic concentrations were associated with high BP, although the causal effect cannot be established from the current study design. Elimination of environmental chemicals in humans would still need to be continued.