•First large-scale study on exposure to PFRs in an European population.•Six metabolites of 7 PFRs were frequently detected in Flemish adolescents.•Relatively high exposure to EHDPHP as confirmed by ...two urinary metabolites.•Socio-economic status and building materials were determinants of exposure.•Estimated daily intakes were all below oral reference doses (RfD)
The ubiquitous use of organophosphate flame retardants and plasticizers (PFRs) in a variety of consumer products has led to widespread human exposure. Since certain PFRs are developmental and carcinogenic toxicants, detailed exposure assessments are essential to investigate the risk associated with environmental exposure levels. However, such data are still lacking for European countries. In this study, concentrations of thirteen PFR metabolites were measured in urine samples from 600 adolescents from Flanders, Belgium. 1-Hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP), diphenyl phosphate (DPHP), bis(1,3-dichloro-isopropyl) phosphate (BDCIPP), 2-hydroxyethyl bis(2-butoxyethyl) phosphate (BBOEHEP), 2-ethylhexyl phenyl phosphate (EHPHP) and 2-ethyl-5-hydroxyhexyl diphenyl phosphate (5-HO-EHDPHP) were frequently detected (>83%) in all participants. Comparisons with study populations from outside the EU showed that urinary levels of DPHP, BDCIPP and BCIPHIPP were generally within the same range. Only exposure to 2-ethylhexyl diphenyl phosphate (EHDPHP) was presumably higher in Flemish adolescents. However, determinants analysis through multivariate regression analyses did not reveal significant predictors that may explain this finding. Significantly higher levels of BDCIPP were observed in participants with new decorations at home, while adolescents with highly educated parents had higher levels of BBOEHEP and BDCIPP. Furthermore, multiple PFR metabolite concentrations followed a seasonal pattern. Estimated daily intakes (EDIs) were calculated from the internal dose by including fractions of urinary excretion (FUE) estimated in in vitro metabolism studies. EDIs ranged from 6.3 ng/kg bw/day for TBOEP to 567.7 ng/kg bw/day for EHDPHP, which were well below the available oral reference doses for all investigated PFRs. This suggests that the associated risk is low at present. This is the first report on internal exposure to seven commonly used PFRs in a European population.
Prenatal chemical exposure has frequently been associated with reduced fetal growth although results have been inconsistent. Most studies associate single pollutant exposure to this health outcome, ...even though this does not reflect real life situations as humans are exposed to many pollutants during their life time. The objective of this study is to investigate the association between prenatal exposure to a mixture of persistent environmental chemicals and birth weight using multipollutant models.
We combined exposure biomarker data measured in cord blood samples of 1579 women from four Flemish birth cohorts collected over a 10 years’ time period. The common set of available and detectable exposure measures in these cohorts are three polychlorinated biphenyls (PCB) congeners (138, 153 and 180), hexachlorobenzene (HCB), dichlorodiphenyldichloroethylene (p,p’-DDE) and the metals cadmium and lead. Multiple linear regression (MLR), Bayesian Information Criterion (BIC), penalized regression using minimax concave penalty (MCP) and Bayesian Adaptive Sampling (BAS) were applied to assess the influence of multiple pollutants in a single analysis on birth weight, adjusted for a priori selected covariates.
In the pooled dataset, a median (P25-P75) birth weight and gestational age of 3420 (3140–3700) grams and 39 (39–40) weeks was observed respectively. The median contaminant levels in cord blood were: 15.8, 26.5, 18.0, 16.9 and 91.5 ng/g lipid for PCB 138, PCB 153, PCB 180, HCB and p,p’-DDE, respectively, 0.075 µg/L for cadmium and 9.7 µg/L for lead. According to the applied statistical methods for multipollutant assessment, p,p’-DDE and PCB 180 were most consistently associated with birth weight. In addition, PCB 153 was selected when applying MCP and BAS. An inverse association with birth weight was found for the PCB congeners, while an increased birth weight was observed for elevated levels of p,p’-DDE.
Assessing the health risk of combinations of exposure biomarkers reflects better real-world situations and thereby allows more effective risk assessment. Our results add to the existing evidence based on detrimental effects of PCBs on birth weight and indicate a possible increase in birth weight due to p,p’-DDE (while correcting for PCBs).
Objectives: Exposure to high concentrations of persistent organochlorines may cause fetal toxicity, but the evidence at low exposure levels is limited. Large studies with substantial exposure ...contrasts and appropriate exposure assessment are warranted. Within the framework of the EU (European Union) ENRIECO (ENvironmental Health Risks in European Birth Cohorts) and EU OBELIX (OBesogenic Endocrine disrupting chemicals: Linking prenatal eXposure to the development of obesity later in life) projects, we examined the hypothesis that the combination of polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) adversely affects birth weight. Methods: We used maternal and cord blood and breast milk samples of 7,990 women enrolled in 15 study populations from 12 European birth cohorts from 1990 through 2008. Using identical variable definitions, we performed for each cohort linear regression of birth weight on estimates of cord serum concentration of PCB-153 and P,P'-DDE adjusted for gestational age and a priori selected covariates. We obtained summary estimates by meta-analysis and performed analyses of interactions. Results: The median concentration of cord serum PCB-153 was 140 ng/L (range of cohort medians 20-484 ng/L) and that of P,P'-DDE was 528 ng/L (range of cohort medians 50-1,208 ng/L). Birth weight decreased with increasing cord serum concentration of PCB-153 after adjustment for potential confounders in 12 of 15 study populations. The meta-analysis including all cohorts indicated a birth weight decline of 150 g 95% confidence interval (CI): -250, -50 g per 1-ug/L increase in PCB-153, an exposure contrast that is close to the range of exposures across the cohorts. A 1-ug/L increase in P, P'-DDE was associated with a 7-g decrease in birth weight (95% CI: —18, 4 g). Conclusions: The findings suggest that low-level exposure to PCB (or correlated exposures) impairs fetal growth, but that exposure to P,P'-DDE does not.The study adds to mounting evidence that low-level exposure to PCBs is inversely associated with fetal growth.
Prenatal chemical exposure has been frequently associated with reduced fetal growth by single pollutant regression models although inconsistent results have been obtained. Our study estimated the ...effects of exposure to single pollutants and mixtures on birth weight in 248 mother-child pairs. Arsenic, copper, lead, manganese and thallium were measured in cord blood, cadmium in maternal blood, methylmercury in maternal hair, and five organochlorines, two perfluorinated compounds and diethylhexyl phthalate metabolites in cord plasma. Daily exposure to particulate matter was modeled and averaged over the duration of gestation. In single pollutant models, arsenic was significantly associated with reduced birth weight. The effect estimate increased when including cadmium, and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) co-exposure. Combining exposures by principal component analysis generated an exposure factor loaded by cadmium and arsenic that was associated with reduced birth weight. MECPP induced gender specific effects. In girls, the effect estimate was doubled with co-exposure of thallium, PFOS, lead, cadmium, manganese, and mercury, while in boys, the mixture of MECPP with cadmium showed the strongest association with birth weight. In conclusion, birth weight was consistently inversely associated with exposure to pollutant mixtures. Chemicals not showing significant associations at single pollutant level contributed to stronger effects when analyzed as mixtures.
Infant exposure to persistent organic pollutants (POPs) may contribute to obesity. However, many studies so far have been small, focused on transplacental exposure, used an inappropriate measure to ...assess postnatal exposure through breastfeeding if any, or did not discern between prenatal and postnatal effects.
We investigated prenatal and postnatal exposure to POPs and infant growth (a predictor of obesity).
We pooled data from seven European birth cohorts with biomarker concentrations of polychlorinated biphenyl 153 (PCB-153) (n = 2,487), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) (n = 1,864), estimating prenatal and postnatal POPs exposure using a validated pharmacokinetic model. Growth was change in weight-for-age z-score between birth and 24 months. Per compound, multilevel models were fitted with either POPs total exposure from conception to 24 months or prenatal or postnatal exposure.
We found a significant increase in growth associated with p,p'-DDE, seemingly due to prenatal exposure (per interquartile increase in exposure, adjusted β = 0.12; 95% CI: 0.03, 0.22). Due to heterogeneity across cohorts, this estimate cannot be considered precise, but does indicate that an association with infant growth is present on average. In contrast, a significant decrease in growth was associated with postnatal PCB-153 exposure (β = -0.10; 95% CI: -0.19, -0.01).
To our knowledge, this is the largest study to date of POPs exposure and infant growth, and it contains state-of-the-art exposure modeling. Prenatal p,p'-DDE was associated with increased infant growth, and postnatal PCB-153 with decreased growth at European exposure levels.
•New technical developments should facilitate that data are FAIR.•Implementation of common ontologies and data harmonization should enable data re-use.•Environment and Health (E&H) data should be ...part of the European Open Science Cloud.•Interconnect and synergize different research domains for optimal use of data.•An EU level E&H data research infrastructure is needed to support E&H research.
Management of datasets that include health information and other sensitive personal information of European study participants has to be compliant with the General Data Protection Regulation (GDPR, Regulation (EU) 2016/679). Within scientific research, the widely subscribed’FAIR’ data principles should apply, meaning that research data should be findable, accessible, interoperable and re-usable. Balancing the aim of open science driven FAIR data management with GDPR compliant personal data protection safeguards is now a common challenge for many research projects dealing with (sensitive) personal data.
In December 2020 a workshop was held with representatives of several large EU research consortia and of the European Commission to reflect on how to apply the FAIR data principles for environment and health research (E&H). Several recent data intensive EU funded E&H research projects face this challenge and work intensively towards developing solutions to access, exchange, store, handle, share, process and use such sensitive personal data, with the aim to support European and transnational collaborations. As a result, several recommendations, opportunities and current limitations were formulated.
New technical developments such as federated data management and analysis systems, machine learning together with advanced search software, harmonized ontologies and data quality standards should in principle facilitate the FAIRification of data. To address ethical, legal, political and financial obstacles to the wider re-use of data for research purposes, both specific expertise and underpinning infrastructure are needed. There is a need for the E&H research data to find their place in the European Open Science Cloud. Communities using health and population data, environmental data and other publicly available data have to interconnect and synergize. To maximize the use and re-use of environment and health data, a dedicated supporting European infrastructure effort, such as the EIRENE research infrastructure within the ESFRI roadmap 2021, is needed that would interact with existing infrastructures.
Exposure to air pollution during pregnancy has been associated with adverse pregnancy outcomes in studies worldwide, other studies have described beneficial effects of residential greenspace on ...pregnancy outcomes. The biological mechanisms that underlie these associations are incompletely understood. A biological stress response, which implies release of cortisol, may underlie associations of air pollution exposure and access to neighborhood greenspaces with health.
We explored residential exposure to air pollution and residential access to neighborhood greenspaces in relation to hair cortisol concentrations of participants in a prospective pregnancy cohort study in Flanders, Belgium. Hair samples were collected at the end of the second pregnancy trimester (n = 133) and shortly after delivery (n = 81). Cortisol concentrations were measured in 3-cm scalp-near hair sections, to reflect second and third pregnancy trimester cortisol secretion. We estimated long-term (3 months before sampling) residential exposure to fine particulate matter (PM
), nitrogen dioxide (NO
) and black carbon (BC), assessed residential distance to major roads and residential access to neighborhood greenspaces (NHGS). Associations between residential exposures and hair cortisol concentrations were studied using linear regression models while adjusting for season of sampling.
Three-month mean residential NO
and BC concentrations were positively associated with third pregnancy trimester hair cortisol concentrations (p = 0.008 and p = 0.017). Access to a large NHGS (10 ha or more within 800 m from residence) was negatively associated with third trimester hair cortisol concentrations (p = 0.019). Access to a large NHGS significantly moderated the association between residential proximity to major roads and second trimester hair cortisol concentrations (p = 0.021). Residential distance to major roads was negatively associated with second trimester hair cortisol concentrations of participants without access to a large NHGS (p = 0.003). The association was not significant for participants with access to a large NHGS. The moderation tended towards significance in the third pregnancy trimester (p < 0.10).
Our findings suggest a positive association between long-term residential exposure to air pollution and biological stress during pregnancy, residential access to neighborhood greenspaces may moderate the association. Further research is needed to confirm our results.
The IPANEMA study is registered under number NCT02592005 at clinicaltrials.gov .
Currently used pesticides are rapidly metabolised and excreted, primarily in urine, and urinary concentrations of pesticides/metabolites are therefore useful biomarkers for the integrated exposure ...from all sources. Pyrethroid insecticides, the organophosphate insecticide chlorpyrifos, and the herbicide glyphosate, were among the prioritised substances in the HBM4EU project and comparable human biomonitoring (HBM)-data were obtained from the HBM4EU Aligned Studies. The aim of this review was to supplement these data by presenting additional HBM studies of the priority pesticides across the HBM4EU partner countries published since 2000. We identified relevant studies (44 for pyrethroids, 23 for chlorpyrifos, 24 for glyphosate) by literature search using PubMed and Web of Science. Most studies were from the Western and Southern part of the EU and data were lacking from more than half of the HBM4EU-partner countries. Many studies were regional with relatively small sample size and few studies address residential and occupational exposure. Variation in urine sampling, analytical methods, and reporting of the HBM-data hampered the comparability of the results across studies. Despite these shortcomings, a widespread exposure to these substances in the general EU population with marked geographical differences was indicated. The findings emphasise the need for harmonisation of methods and reporting in future studies as initiated during HBM4EU.
Humans are exposed to multiple environmental chemicals via different sources resulting in complex real-life exposure patterns. Insight into these patterns is important for applications such as ...linkage to health effects and (mixture) risk assessment. By providing internal exposure levels of (metabolites of) chemicals, biomonitoring studies can provide snapshots of exposure patterns and factors that drive them. Presentation of biomonitoring data in networks facilitates the detection of such exposure patterns and allows for the systematic comparison of observed exposure patterns between datasets and strata within datasets.
We demonstrate the use of network techniques in human biomonitoring data from cord blood samples collected in three campaigns of the Flemish Environment and Health Studies (FLEHS) (sampling years resp. 2002-2004, 2008-2009, and 2013-2014). Measured biomarkers were multiple organochlorine compounds, PFAS and metals. Comparative network analysis (CNA) was conducted to systematically compare networks between sampling campaigns, smoking status during pregnancy, and maternal pre-pregnancy BMI.
Network techniques offered an intuitive approach to visualize complex correlation structures within human biomonitoring data. The identification of groups of highly connected biomarkers, "communities," within these networks highlighted which biomarkers should be considered collectively in the analysis and interpretation of epidemiological studies or in the design of toxicological mixture studies. Network analyses demonstrated in our example to which extent biomarker networks and its communities changed across the sampling campaigns, smoking status during pregnancy, and maternal pre-pregnancy BMI.
Network analysis is a data-driven and intuitive screening method when dealing with multiple exposure biomarkers, which can easily be upscaled to high dimensional HBM datasets, and can inform mixture risk assessment approaches.
Background
The successive FLEHS campaigns assess internal exposure to pollutants and associated early biological and health effects in participants of different age groups.
Materials and methods
...Mother–newborn pairs (
N
= 220 in 2008–2009, age 18–42 years;
N
= 269 in 2013–2014, age 18–44 years), 197 adolescents 14–15 years (2010–2011), 201 adults 20–40 years (2008–2009) and 205 adults 50–65 years (2014) were recruited. For the various groups of subjects different sets of PFAS were assessed. Perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorobutane sulfonate (PFBS) were determined in cord plasma and peripheral serum as these were the PFAS compounds for which we had access to high quality measurements and which were expected to be present in the highest concentrations. Participants filled out a questionnaire based on the European Community Respiratory Health Survey questionnaire on asthma and allergy. In these cross-sectional studies associations were assessed using stepwise multiple logistic regression, with confounders (including smoking and familial occurrence of the disease) and potential covariates selected on the basis of experience in our previous studies and a literature search. Forest plots of odds ratios summarize the associations between the various PFAS on the one hand and the different immune outcomes on the other hand.
Results
For several self-reported immune system-related diseases inverse associations with PFAS serum concentrations were observed. These inverse associations were more pronounced in mothers and adults than in adolescents. A significant inverse association was observed in adults and mothers (for mothers based on measurements on cord plasma) between PFNA, PFOS, and PFHxS and asthma (for mothers also for PFOA), in mothers between PFHxS, PFNA and PFOS and allergic rhinitis, in mothers and adults between PFHxS and PFOS and some forms of allergy (for mothers also for PFOA), in adults between PFOA and eczema, and in adolescents between PFOS and systemic allergy.
Conclusion
Internal exposure to PFAS was associated with changes in immunological processes consistent with what has been reported in the literature. Whereas these changes were observed in many publications to be associated with adverse health effects, our findings suggest that they can also lead to inverse associations with certain immune system-related diseases.
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