Human Biomonitoring Guidance Values (HBM-GVs) for Bisphenol S and Assessment of the Risk Due to the Exposure to Bisphenols A and S, in Europe.

Within the European Joint Programme HBM4EU, Human Biomonitoring Guidance Values (HBM-GVs) were derived for several prioritised substances. In this paper, the derivation of HBM-GVs for the general population (HBM-GVGenPop) and workers (HBM-GVworker) referring to bisphenol S (BPS) is presented. For the general population, this resulted in an estimation of the total urinary concentration of BPS of 1.0 µg/L assuming a 24 h continuous exposure to BPS. For workers, the modelling was refined in order to reflect continuous exposure during the working day, leading to a total urinary concentration of BPS of 3.0 µg/L. The usefulness for risk assessment of the HBM-GVs derived for BPS and bisphenol A (BPA) is illustrated. Risk Characterisation Ratios (RCRs) were calculated leading to a clear difference between risk assessments performed for both bisphenols, with a very low RCR regarding exposure to BPA., contrary to that obtained for BPS. This may be due to the endocrine mediated endpoints selected to derive the HBM-GVs for BPS, whereas the values calculated for BPA are based on the temporary Tolerable Daily Intake (t-TDI) from EFSA set in 2015. A comparison with the revised TDI recently opened for comments by EFSA is also discussed. Regarding the occupational field, results indicate that the risk from occupational exposure to both bisphenols cannot be disregarded.

Spatio-temporal assessment of pregnant women exposure to chlorpyrifos at a regional scale.

BACKGROUND: The aim of this study was to use an integrated exposure assessment approach, combining spatiotemporal modeling of environmental exposure and fate of the chemical to assess the exposure of vulnerable populations. In this study, chlorpyrifos exposure of pregnant women in Picardy was evaluated at a regional scale during 1 year. This approach provided a mapping of exposure indicators of pregnant women to chlorpyrifos over fine spatial and temporal resolutions using a GIS environment. METHODS: Fate and transport models (emission, atmospheric dispersion, multimedia exposure, PBPK) were combined with environmental databases in a GIS environment. Quantities spread over agricultural fields were simulated and integrated into a modeling chain coupling models. The fate and transport of chlorpyrifos was characterized by an atmospheric dispersion statistical metamodel and the dynamiCROP model. Then, the multimedia model Modul'ERS was used to predict chlorpyrifos daily exposure doses which were integrated in a PBPK model to compute biomarker of exposure (TCPy urinary concentrations). For the concentration predictions, two scenarios (lower bound and upper bound) were built. RESULTS: At fine spatio-temporal resolutions, the cartography of biomarkers in the lower bound scenario clearly highlights agricultural areas. In these maps, some specific areas and hotspots appear as potentially more exposed specifically during application period. Overall, predictions were close to biomonitoring data and ingestion route was the main contributor to chlorpyrifos exposure. CONCLUSIONS: This study demonstrated the feasibility of an integrated approach for the evaluation of chlorpyrifos exposure which allows the comparison between modeled predictions and biomonitoring data.

Characterizing environmental geographic inequalities using an integrated exposure assessment.

BACKGROUND: At a regional or continental scale, the characterization of environmental health inequities (EHI) expresses the idea that populations are not equal in the face of pollution. It implies an analysis be conducted in order to identify and manage the areas at risk of overexposure where an increasing risk to human health is suspected. The development of methods is a prerequisite for implementing public health activities aimed at protecting populations. METHODS: This paper presents the methodological framework developed by INERIS (French National Institute for Industrial Environment and Risks) to identify a common framework for a structured and operationalized assessment of human exposure. An integrated exposure assessment approach has been developed to integrate the multiplicity of exposure pathways from various sources, through a series of models enabling the final exposure of a population to be defined. RESULTS: Measured data from environmental networks reflecting the actual contamination of the environment are used to gauge the population's exposure. Sophisticated methods of spatial analysis are applied to include additional information and take benefit of spatial and inter-variable correlation to improve data representativeness and characterize the associated uncertainty. Integrated approaches bring together all the information available for assessing the source-to-human-dose continuum using a Geographic Information System, multimedia exposure and toxicokinetic model. DISCUSSION: One of the objectives of the integrated approach was to demonstrate the feasibility of building complex realistic exposure scenarios satisfying the needs of stakeholders and the accuracy of the modelling predictions at a fine spatial-temporal resolution. A case study is presented to provide a specific application of the proposed framework and how the results could be used to identify an overexposed population. CONCLUSION: This framework could be used for many purposes, such as mapping EHI, identifying vulnerable populations and providing determinants of exposure to manage and plan remedial actions and to assess the spatial relationships between health and the environment to identify factors that influence the variability of disease patterns.

Effects of waterborne uranium on survival, growth, reproduction and physiological processes of the freshwater cladoceran Daphnia magna.

Acute uranium toxicity (48 h immobilisation test) for Daphnia magna was determined in two different exposure media, differing in pH and alkalinity. LC(50) varied strongly between media, from 390+/-40 microgL(-1)U at pH 7 to 7.8+/-3.2 mgL(-1)U at pH 8. According to the free ion activity model uranium toxicity varies as a function of free uranyl concentration. This assumption was examined by calculating uranium speciation in our water conditions and in those reported in the literature. Predicted changes in free uranyl concentration could not solely explain observed differences in toxicity, which might be due to a competition or a non-competitive inhibition of H(+) for uranium transport and/or the involvement of other bioavailable chemical species of uranium. Chronic effects of uranium at pH 7 on mortality, ingestion and respiration, fecundity and dry mass of females, eggs and neonates were investigated during 21-day exposure experiments. A mortality of 10% was observed at 100 microgL(-1)U and EC(10) for reproduction was 14+/-7 microgL(-1)U. Scope for growth was affected through a reduction in feeding activity and an increase in oxygen consumption at 25 microgL(-1)U after 7 days of exposure. This had strong consequences for somatic growth and reproduction, which decreased, respectively, by 50% and 65% at 50 microgL(-1)U after 7 days and at 25 microgL(-1)U after 21 days. Uranium bioaccumulation was quantified and associated internal alpha dose rates from 2.1 to 13 microGyh(-1) were estimated. Compared to the toxicity of other alpha-emitting radionuclides and stable trace metals, our results confirmed the general assumption that uranium chemical toxicity predominates over its radiotoxicity.