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One of the major goals of the European Human Biomonitoring Initiative (HBM4EU) was to bridge the gap between science and policy by consulting both policy makers and national scientists and generating evidence of the actual exposure of residents to chemicals and whether that exposure would be suggest a potential health risk. Residents’ perspectives on chemical exposure and risk were also investigated. HBM4EU's research was designed to answer specific short-term and long-term policy questions at national and European levels, and for its results to directly support regulatory action on chemicals. A strategy was established to prioritise chemicals for analysis in human matrices, with a total of 18 substances/substance groups chosen to be investigated throughout the five-and a -half-year project. HBM4EU produced new evidence of human exposure levels, developed reference values for exposure, investigated determinants of exposure and derived health-based guidance values for those substances. In addition, HBM4EU promoted the use of human biomonitoring data in chemical risk assessment and developed innovative tools and methods linking chemicals to possible health impacts, such as effect biomarkers. Furthermore, HBM4EU advanced understand of effects from combined exposures and methods to identify emerging chemicals. With the aim of supporting policy implementation, science-to-policy workshops were organised, providing opportunities for joint reflection and dialogue on research results. I, and indicators were developed to assess temporal and spatial patterns in the exposure of European population. A sustainable human biomonitoring monitoring framework, producing comparable quality assured data would allow: the evaluation of time trends; the exploration of spatial trends: the evaluation of the influence of socio-economic conditions on chemical exposure. Therefore, such a framework should be included in the European Chemicals' Strategy for Sustainability and the data would support the Zero Pollution Action Plan.

Introduction: Pesticides, including herbicides, are widely used for agricultural and sanitary reasons and concerns have been raised about their various health effects. Little research has been done into the extent to which agricultural land use in the residential surroundings contributes to (internal) exposure of pesticides. Objectives: We investigated the associations between the proportion of agricultural land use around the residence and the exposure to pesticides in adolescents in Flanders (Belgium).Material and methods: We included 424 adolescents participating in the fourth Flemish Environment and Health Study (FLEHS IV) between 2016 and 2020. The residential address of all participants was geocoded and the proportion of agricultural land use around the residence was estimated in several buffers (300 m, 500 m, 1000 m and 2000 m). The concentrations of the following biomarkers of pesticides were measured in urine and adjusted for the specific gravity: glyphosate and its metabolite, aminomethyl-phosphonic acid (AMPA); 3-phenoxybenzoic acid (3-PBA); 3,5,6-trichloro-2-pyridinol (TCPy) and 2,4-dichlophenoxy-acetic acid (2,4-D). We categorized the pesticide biomarkers in three categories according to the exposure levels and used ordinal logistic regression models adjusted for sex, season and household education to estimate the odds ratio for an increase in an interquartile range (IQR) of proportion of agricultural land use. We also used binary logistic regression models in which the category of highest exposure was compared to the category of lowest exposure. In addition, we explored potential effect modification by sex and season.Results: We found a significant association between the proportion of agricultural land use in a buffer of 2000 m around the residence and the levels of urinary AMPA divided into three categories (OR = 1.35 for an IQR in-crease in the proportion of agricultural land use around residence; 95% CI: 1.00-1.83). This association was less pronounced and not statistically significant for the other studied pesticides (OR ranging between 0.95 and 1.16). Stratified analysis showed the strongest association of the proportion of agricultural land use within 2000 m buffers for AMPA among boys (OR = 1.89; 95% CI: 1.19-3.04). Results using smaller buffers were comparable, but did not reach statistical significance. This paper is based on research conducted within the framework of the Flemish Center of Expertise on Environment and Health (FLEHS, 2016–2020), funded by the Government of Flanders, Department of Environment & Spatial Development and the European H2020 Human Biomonitoring program HBM4EU. We kindly want to thank Flemming Nielsen for his contribution to this study.

Chronic biological stress may adversely affect adolescents' physical and mental health, but insight in the personal and environmental factors that determine chronic stress is limited. We measured 3-month cumulative hair cortisol concentration (HCC) in 419 adolescents, participating in the Flemish Environment and Health Study. Adolescents' health and lifestyle characteristics, household and neighborhood socio-economic status as well as neighborhood urbanicity were assessed as potential determinants of HCC, using multiple linear regression models. We additionally explored heterogeneity of our results by sex. HCC were significantly higher in boys from densely populated neighborhoods, the association was not significant in girls. Accordingly, boys living outside cities had significantly lower HCC than boys, living in cities. HCC was significantly lower in adolescents with an optimal vitality, a measure of a positive mental health status. In adolescent girls, menarcheal status (pre-/postmenarche) was a significant determinant of HCC. Our findings are the first to suggest that residential urbanicity may have an impact on chronic biological stress in a general population of adolescent boys. This paper is based on research conducted within the framework of the Flemish Center of Expertise on Environment and Health (FLEHS 2016-2020), funded by the Government of Flanders, Department of Environment & Spatial Development. VV was supported by a PhD fellowship at the University of Antwerp and VITO, funded by the Flemish Center of Expertise on Environment and Health. We thank the adolescents and their families who participated in FLEHS IV. Without their effort, this study would not have been possible. We thank the field workers from the Provincial Institute of Hygiene and VITO for the sample and data collection.

Mitochondria] DNA (mtDNA) content and telomere length are putative aging biomarkers and are sensitive to environmental stressors, including pollutants. Our objective was to identify, from a set of environmental exposures, which exposure is associated with leukocyte mtDNA content and telomere length in adults. This study includes 175 adults from 50 to 65 years old from the cross-sectional Flemish Environment and Health study, of whom leukocyte telomere length and mtDNA content were determined using qPCR. The levels of exposure of seven metals, 11 organohalogens, and four perfluorinated compounds (PFHxS, PFNA, PFOA, PFOS) were measured. We performed sparse partial least-squares regression analyses followed by ordinary least-squares regression to assess the multipollutant associations. While accounting for possible confounders and coexposures, we identified that urinary cadmium (6.52%, 95% confidence interval, 1.06, 12.28), serum hexachlorobenzene (2.89%, 018, 5.68), and perfluorooctanesulfonic acid (11.38%, 5.97, 17.08) exposure were positively associated (p < 0.05) with mtDNA content, while urinary copper (-9.88%, -14.82, -4.66) and serum perfluorohexanesulfonic acid (-4.75%, -8.79, -0.54) exposure were inversely associated with mtDNA content. Urinary antimony (2.69%, 0.45, 4.99) and mercury (1.91%, 0.42, 3.43) exposure were positively associated with leukocyte telomere length, while urinary copper (-3.52%, -6.60, -0.34) and serum perfluorooctanesulfonic acid (-3.64%, -6.60, -0.60) showed an inverse association. Our findings support the hypothesis that environmental pollutants interact with molecular hallmarks of aging.

Human biomonitoring (HBM) monitors levels of environmental pollutants in human samples, which often is a topic of concern for residents near industrially contaminated sites (ICSs). Around an ICS area in Menen (Belgium), including a (former) municipal waste incinerator and a metal recovery plant, increasing environmental concentrations of dioxins and polychlorinated biphenyls (PCBs) were observed, causing growing concern among residents and authorities. The local community succeeded in convincing the responsible authorities to investigate the problem and offer research funding. Persistent organic pollutants (POPs) were measured in two consecutive HBM studies (2002-2006 and 2010-2011), in the context of the Flemish Environment and Health Study (FLEHS), as well as in soil and locally produced food. Meanwhile, local authorities discouraged consumption of locally produced food in a delineated area of higher exposure risk. Ultimately, HBM and environmental data enabled tailored dietary recommendations. This article demonstrates the usefulness of HBM in documenting the body burdens of residents near the ICS, identifying exposure routes, evaluating remediating actions and providing information for tailored policy strategies aiding to further exposure reduction. It also highlights the role of the local stakeholders as an example of community-based participatory research and how such an approach can create societal support for research and policy. Funding: The HBM studies were conducted within the framework of the Flemish Center of Expertise on Environment and Health (FLEHS 2002–2006 and 2007–2011), funded by the Flemish Government, Department of Environment & Spatial Development, Flemish Planning Bureau for the Environment and Spatial Development (formally: Department of Environment, Nature & Energy); Department of Economics, Science and Innovation and the Flemish Agency for Care and Health. The scienceto-policy process of the HBM results was funded by the Department of Environment & Spatial Development, Flemish Planning Bureau for the Environment and Spatial Development (formally: Department of Environment, Nature & Energy) and the Flemish Agency for Care and Health. The egg study was funded by the Government of Flanders, Department of Environment & Spatial Development, Flemish Planning Bureau for the Environment and Spatial Development (formally: Department of Environment, Nature & Energy); the Flemish Agency for Care and Health and the Flanders Environment Agency. The views expressed herein are those of the author(s) and are not necessarily endorsed by the Flemish Government. Acknowledgments: The authors wish to express their gratitude to the participants of the studies for their cooperation and to the study nurses and study fieldworkers for their contribution to the study. We also thank the SGS laboratory for collection and analysis of the egg samples and Josworld for designing the leaflet on dietary recommendations for consumption of home-produced eggs.

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. We thank the participating adolescents and their families. Without their effort this study would not have been possible. We also thank J. Bombeke for his assistance during the sample preparation. This paper is based on research conducted within the framework of the Flemish Center of Expertise on Environment and Health (FLEHS 2016-2020), funded by the Government of Flanders, Department of Environment & Spatial Development. The views expressed herein are those of the author (s) and are not necessarily endorsed by the government of Flanders. The Flemish Environment and Health Study was commissioned, financed and steered by the Ministry of the Flemish Community (Department of Environment) (grant ID: Steunpunt Milieu & Gezondheid), including the partial funding of the Ph.D. of Michiel Bastiaensen. Celine Gys acknowledges the funding of a PhD fellowship from Research Foundation Flanders (project G0E5216N).

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants of public health concern. Multiple biological mechanisms have been hypothesized to contribute to PAHs-associated adverse health effects. Little is known about the impact of PAHs on endocrine stress and inflammation in adolescence. We examined 393 Flemish adolescents (14-15 years) cross-sectionally, measured urinary concentrations of hydroxylated naphthalene, fluorene, phenanthrene and pyrene metabolites, and calculated the sum of all measured metabolites. We determined hair cortisol concentration (HCC) as endocrine stress biomarker, leucocyte counts and neutrophil-lymphocyte ratio (NLR) in peripheral blood as inflammatory biomarkers, and urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) concentration as oxidative stress biomarker. Exposure-response associations were analyzed by multiple regression, adjusted for a priori selected covariates. A doubling of 1-hydroxypyrene concentration was associated with a factor of 1.13 (95% CI: 1.03, 1.24) increase in HCC and a factor of 1.07 (95% CI: 1.02, 1.13) increase in 8-oxodG. Doublings of 2- and 3-hydroxyphenanthrene concentrations were associated with a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.00, 1.12) increase in 8-oxodG, respectively. Doubling of 2-hydroxyphenanthrene and of the sum of 2- and 3-hydroxyfluorene was associated with, respectively, a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.01, 1.13) increase in NLR. Our results indicate the glucocorticoid pathway as a potential target for PAH exposure in adolescents and suggest oxidative stress, endocrine stress, and inflammation in adolescence as underlying mechanisms and early markers for PAH-related adverse health effects. Government of Flanders, Department of Environment & Spatial Development; Flemish Center of Expertise on Environment and Health

As part of the Human Biomonitoring for Europe (HBM4EU) initiative a human biomonitoring (HBM) survey is conducted in 21 countries. This survey builds on existing HBM capacity in Europe by aligning national or regional HBM studies. The survey targets 3 age groups (i) children aged 6-11 years, (ii) teenagers aged 12-19 years and (iii) young adults aged 20-39 years and includes a total of 9493 participants (3151 children, 2953 teenagers and 3389 young adults). Depending on the age group, internal exposure to phthalates and substitute Hexamoll® DINCH, brominated and organophosphorus flame retardants, per-/poly-fluorinated compounds, cadmium, bisphenols and/or polycyclic aromatic hydrocarbons are assessed. The main goal of the programme is to obtain quality controlled and comparable HBM data of exposure to chemicals, prioritized under HBM4EU, with European wide coverage to inform the development of environment and health policies. This paper describes the framework of the HBM4EU survey and the approach that has been applied to align European HBM initiatives across Europe. HBM4EU is co-financed under Horizon 2020 (grant agreement No 733032). The authors thank all principle investigators of the contributing studies for their participation and contribution to the joint HBM4EU survey and the national programme owners for their financial support. In addition we want to thank Dr. Liesbeth Bruckers and Dr. Michael Schümann. Sí

Background: Exposure to air pollution and traffic noise are associated with adverse health outcomes in adolescents. Chronic endocrine stress and systemic inflammation have been hypothesized to underlie the adverse health effects. Simultaneous assessment of inflammation and chronic endocrine stress in epidemiological studies is lacking. The aim of the study was to investigate biomarkers of chronic endocrine stress and inflammation in relation to long-term residential exposure to air pollution and traffic noise in adolescents. Methods: In Flemish adolescents (14-15 years), we determined hair cortisol concentration (HCC) as a chronic stress biomarker in 3-cm scalp-near hair sections (n = 395), and leucocyte and leucocyte subtype counts (neutrophils, monocytes, lymphocytes) as inflammatory biomarkers in peripheral blood (n = 385). Daily particulate matter (PM2.5, PM10), nitrogen dioxide (NO2) and black carbon (BC) concentrations were modelled at the residential address and averaged over 3-month and 1-year periods prior to sampling. Residential traffic noise level was estimated and classified in 5 dB intervals. Sex-specific associations between residential exposures and effect biomarkers were studied using linear regression models, adjusted for a priori selected covariates. Results: In boys, HCC increased with a factor 1.30 (95% CI: 1.10, 1.54) for an increase in 1-year mean NO2 from the 25th to 75th percentile (p75/p25), after adjustment for age, BMI, personal and neighborhood socioeconomic status. The corresponding estimate for PM10 was 1.24 (95% CI: 1.02, 1.51). Total leucocyte count in boys, adjusted for the aforementioned covariates and recent health complaints, was positively associated with PM2.5, PM10, NO2 and BC. In particular, the neutrophil count increased with a factor 1.11 (95% CI: 1.03, 1.19) for a (p75/p25)-factor increase in 1-year mean BC, corresponding estimates for PM2.5, PM10 and NO2 were 1.10 (95% CI: 1.01, 1.19), 1.10 (95% CI: 1.01, 1.20) and 1.08 (95% CI: 1.00, 1.16). Lymphocyte count increased with a factor 1.05 (95% CI: 1.01, 1.10) for a (p75/p25)-factor increase in 1-year mean NO2. Similar results were observed for 3-month mean exposures. Results were robust to adjustment for recent air pollution exposure. In girls, air pollutants were not associated with HCC or differential leucocyte count. Residential traffic noise level was not associated with HCC or leucocyte counts in boys nor girls. Conclusions: Long-term residential exposure to air pollutants was positively associated with chronic endocrine stress and inflammation in adolescent boys, not in girls. This study may contribute to a better understanding of the early pathophysiological changes that may underlie adverse health effects of air pollution exposure in adolescents. Government of Flanders, Department of Environment & Spatial Development; PhD fellowship at the University of Antwerp; VITO - Flemish Center of Expertise on Environment and Health

Nutrition during early childhood is linked to metabolic programming. We hypothesized that breastfeeding has long-term consequences on the energy metabolism exemplified by mitochondrial DNA (mtDNA). As part of the third cycle of the Flemish Environment and Health Study (FLEHSIII) cohort, 303 adolescents aged 14-15 years were included. We associated breastfeeding and blood mtDNA content 14-15 years later while adjusting for confounding variables. Compared with non-breastfed adolescents, mtDNA content was 23.1% (95%CI: 4.4-45.2; p = 0.013) higher in breastfed adolescents. Being breastfed for 1-10 weeks, 11-20 weeks, and >20 weeks, was associated with a higher mtDNA content of respectively 16.0% (95%CI: -7.1-44.9; p = 0.191), 23.5% (95%CI: 0.8-51.3; p = 0.042), and 31.5% (95%CI: 4.3-65.7; p = 0.021). Our study showed a positive association between breastfeeding and mtDNA content in adolescents which gradually increased with longer periods of breastfeeding. Higher mtDNA content may be an underlying mechanism of the beneficial effects of breastfeeding on children's metabolism. ispartof: SCIENTIFIC REPORTS vol:10 issue:1 ispartof: location:England status: published

Because of their dirt-, water- and oil-repelling properties, per- and polyfluoroalkyl substances (PFASs) are frequently used in a broad variety of consumer products. They have been detected in human samples worldwide. In Flanders, Belgium, the Flemish Environment and Health Studies (FLEHS) measured the levels of five PFAS biomarkers in four different age groups of the Flemish population and identified determinants of variability in exposure. Cord plasma or peripheric serum samples and questionnaire data were available for 220 mother-newborn pairs (2008-2009), 269 mother-newborn pairs (2013-2014), 199 adolescents (14-15 years old, 2010), 201 adults (20-40 years old, 2008-2009) and 205 adults (50-65 years old, 2014). Measured levels of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA) in Flanders are in the middle or low range compared to concentrations reported in other Western countries. Levels of perfluorobutanesulfonic acid (PFBS) were below the quantification limit in 98%-100% of the samples. Despite decreasing levels in time for PFOS and PFOA, 77% of the adults (2014) had serum levels exceeding HBM-I values of 5 mu/L for PFOS and 2 mu g/L for PFOA. Beside age, sex, fish consumption, parity and breastfeeding, the multiple regression models identified additionally consumption of offal and locally grown food, and use of cosmetics as possible exposures and menstruation as a possible route of elimination. Better knowledge on determinants of exposure is essential to lower PFASs exposure. This paper is based on research conducted within the framework of the Flemish Centre of Expertise on Environment and Health, funded by the Environment, Nature and Energy Department of the Flemish government, the Department of Public Health and the Department of Science of the Flemish government. The views expressed herein are those of the authors and are not necessarily endorsed by the Flemish government. Colles, A (reprint author), VITO Hlth, Boeretang 200, B-2400 Mol, Belgium. ann.colles@vito.be

Background: Placental mitochondrial DNA (mtDNA) content can be indicative of oxidative damage to the placenta during fetal development and is responsive to external stressors. In utero exposure to environmental pollutants that may influence placental mtDNA needs further exploration. Objectives: We evaluated if placental mtDNA content is altered by environmental pollution in newborns and identified pollutants independently associated to alterations in placental mtDNA content. Methods: mtDNA content was measured in placental tissue of 233 newborns. Four perfluoroalkyl compounds and nine organochlorine compounds were quantified in cord blood plasma samples and six toxic metals in whole cord blood. We first applied a LASSO (least absolute shrinkage and selection operator) penalized regression model to identify independent associations between environmental pollutants and placental mtDNA content, without penalization of several covariates. Then adjusted estimates were obtained using an ordinary least squares (OLS) regression model evaluating the pollutants' association with placental mtDNA content, adjusted for several covariates. Results: Based on LASSO penalized regression, oxychlordane, p,p′-dichlorodiphenyldichloroethylene, β-hexachlorocyclohexane, perfluorononanoic acid, arsenic, cadmium and thallium were identified to be independently associated with placental mtDNA content. The OLS model showed a higher placental mtDNA content of 2.71% (95% CI: 0.3 to 5.2%; p=0.03) and 1.41% (0.1 to 2.8%, p=0.04) for a 25% concentration increase of respectively cord blood β-hexachlorocyclohexane and arsenic. For a 25% concentration increase of cord blood thallium, a 4.88% lower placental mtDNA content (95% CI: -9.1 to −0.5%, p=0.03) was observed. Conclusion: In a multi-pollutant approach, low fetal exposure levels of environmental organic and inorganic pollutants might compromise placental mitochondrial function as exemplified in this study by alterations in mtDNA content. Keywords: Placenta, Mitochondrial DNA content, Environmental pollution, Newborns

Background: Environmental justice research shows how socially disadvantaged groups are more exposed and more vulnerable to environmental pollution. At the same time, these groups are less represented and, thus, less visible in biomedical studies. This socioeconomic participation bias is a form of environmental injustice within research practice itself. Methods: We designed, implemented and evaluated a targeted recruitment strategy to enhance the participation of socially disadvantaged pregnant women in a human biomonitoring study in Belgium. We focused on women of Turkish and Moroccan descent and developed a setup using personal buddies that enabled information transfer about study conditions in the pre-parturition period as well as support and follow-up with questionnaires in the post-parturition period. Results: We identified four barriers to the participation of women with a vulnerable social and ethnic background which were related to psychosocial and situational factors. Lack of trust in researchers and no perceived study benefits were important personal barriers; the complex study design and difficult self-administered questionnaires were equally significant barriers. Conclusion: By investing in direct, person-to-person contact with trusted buddies and supported by practical advice about cultural and linguistic sensitivity, it was possible to increase study participation of socially disadvantaged people. Above all, this required openness and flexibility in the mind-set of researchers so that study design and procedures could be better grounded in the experiences and circumstances of underprivileged groups. The Flemish Environmental and Health Studies (FLEHS) are commissioned, financed and steered by the Ministry of the Flemish Community (Department of Economics, Science and Innovation; Flemish Agency for Care and Health; and the Department of Environment, Nature and Energy). We acknowledge additional financial support from the Flemish government to invest in a targeted recruitment strategy for socially vulnerable people.

To follow time trends in exposure to environmental chemicals, three successive campaigns of the Flemish Environment and Health Study (FLEHS) have recruited and sampled in total 5825 participants between 2002 and 2014. Cord samples from newborns, urine and blood samples from 14 to 15 years old adolescents and from adults between 50 and 65 years old were analysed in geographical representative samples of the Flemish population. The data of the different campaigns were considered per age group and per biomarker after adjustment for predefined covariates to take into account differences in characteristics of the study populations over time. Geometric means were calculated. Multiple linear regression was used to evaluate time trends. The concentration of serum biomarkers for persistent organic pollutants (POPs), such as marker polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p'-DDE), the major metabolite of dichlorodiphenyltrichloroethane (DDT), and hexachlorobenzene (HCB) expressed per g lipid, decreased significantly with time. The levels of DDE in all age groups and those of PCBs in cord and adolescent serum samples were almost halved in a time period of ten years. HCB levels were reduced by a factor of 4 in adolescents and in adults. Mean serum concentrations of the more recently regulated perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were significantly lower in cord samples of 2013 compared to samples of 2007. The decline was more pronounced for PFOS than for PFOA. In the same period, mean metabolite levels of di-2-ethylhexyl phthalate (DEHP) and of di-n-butyl phthalate (DBP) decreased significantly in urine samples of adolescents with sharper declines for DEHP than for DBP. Cadmium and lead levels in cord and adolescent blood samples were significantly lower in the recent campaigns than 10 years before. Also the mean urinary cadmium level in adults was 35% lower compared to adult samples of 2002. Such favourable trends were not observed for arsenic and thallium measured in cord blood. Similar, the concentrations of 1-hydroxypyrene, a marker for exposure to poly cyclic aromatic hydrocarbons (PAHs), was not lower in urine from adolescents sampled in 2013 compared to 2003. In contrast, concentrations of t,t'-muconic acid, a marker of benzene exposure, showed clearly reduced levels. The FLEHS program shows that concentrations of well-regulated chemicals especially traditional POPs and cadmium and lead are decreasing in the population of Flanders. Response to regulatory measures seems to happen rapid, since concentrations in humans of specific regulated perfluorinated compounds and phthalates were significantly reduced in five years time. Biomarker concentrations for arsenic, thallium, and polyaromatic hydrocarbons are not decreasing in this time span and further follow up is warranted. (C) 2016 Published by Elsevier GmbH.

Since 2002, the Flemish Government decided to carry out the Flemish Environment and Health Survey (FLEHS), an extended human biomonitoring (HBM) program, which is integrated in the environmental health policy. Through the FLEHS studies, a vast amount of data such as biomarkers of exposure and effect, exposure effect associations, time trends and geographical differences, became available to the Flemish policy makers. In order to facilitate the policy interpretation, a phased action-plan was developed collaboratively by FLEHS researchers and policy makers. In this article we look back on more than 15 years of investments of the Flemish government in HBM and reflect on how this large scaled and challenging HBM-initiative contributed to shaping the environmental health policy in Flanders. We used the FLEHS I (2002-2006) and II (2007-2011) results on persistent organic pollutants (POPs) and the resulting policy actions as an example to illustrate the added value of HBM for policy making. Policy measures for POPs, including source-related regulation (e.g. further optimization and tightening of existing Flemish legislation on open fires), investment in monitoring networks and communication and awareness campaigns, are presented and the added value for environmental health policy is discussed. We also reflect on how HBM can support science and innovation in the environmental monitoring context. Finally, we describe what society can gain from HBM in terms of opportunities for (1) feeding the political and societal debate, (2) stimulating community involvement and (3) empowering participants and citizens. All together, the gained insights and phased action plan showed that next to compliance with high scientific standards, results of the Flemish human biomonitoring campaign could be translated in targeted policy actions even for chemicals that have since long been regulated. (C) 2016 Elsevier GmbH. All rights reserved.

Background We investigated whether human environmental exposure to chemicals that are labeled as (potential) carcinogens leads to increased (oxidative) damage to DNA in adolescents. Material and methods Six hundred 14–15-year-old youngsters were recruited all over Flanders (Belgium) and in two areas with important industrial activities. DNA damage was assessed by alkaline and formamidopyrimidine DNA glycosylase (Fpg) modified comet assays in peripheral blood cells and analysis of urinary 8-hydroxydeoxyguanosine (8-OHdG) levels. Personal exposure to potentially carcinogenic compounds was measured in urine, namely: chromium, cadmium, nickel, 1-hydroxypyrene as a proxy for exposure to other carcinogenic polycyclic aromatic hydrocarbons (PAHs), t,t-muconic acid as a metabolite of benzene, 2,5-dichlorophenol (2,5-DCP), organophosphate pesticide metabolites, and di(2-ethylhexyl) phthalate (DEHP) metabolites. In blood, arsenic, polychlorinated biphenyl (PCB) congeners 118 and 156, hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and perfluorooctanoic acid (PFOA) were analyzed. Levels of methylmercury (MeHg) were measured in hair. Multiple linear regression models were used to establish exposure-response relationships. Results Biomarkers of exposure to PAHs and urinary chromium were associated with higher levels of both 8-OHdG in urine and DNA damage detected by the alkaline comet assay. Concentrations of 8-OHdG in urine increased in relation with increasing concentrations of urinary t,t-muconic acid, cadmium, nickel, 2,5-DCP, and DEHP metabolites. Increased concentrations of PFOA in blood were associated with higher levels of DNA damage measured by the alkaline comet assay, whereas DDT was associated in the same direction with the Fpg-modified comet assay. Inverse associations were observed between blood arsenic, hair MeHg, PCB 156 and HCB, and urinary 8-OHdG. The latter exposure biomarkers were also associated with higher fish intake. Urinary nickel and t,t-muconic acid were inversely associated with the alkaline comet assay. Conclusion This cross-sectional study found associations between current environmental exposure to (potential) human carcinogens in 14–15-year-old Flemish adolescents and short-term (oxidative) damage to DNA. Prospective follow-up will be required to investigate whether long-term effects may occur due to complex environmental exposures.

industrially contaminated sites (ICSs) have been recognised as a major public health concern since they involve exposure to multiple environmental stressors, normally distributed unevenly within population. The COST Action on Industrially Contaminated Sites and Health Network (ICSHNet) comprises a European network of experts and institutions to clarify needs and priorities for better characterising the impact on environment and health of ICS.evaluate the availability of information and studies concerning selected ICSs in participating Countries within the ICSHNet, with particular consideration on the accessibility to environmental, health and demographic data, and research and assessment tools.to evaluate the availability of data, an Action Questionnaire (AQ) was developed based on previous questionnaires used in different European projects and on expert consultation. The AQ, with 84 items organised in eight sections, was adapted to an on-line version using the software LimeSurvey. The survey was sent to 47 participants within the ICSHNet, to report over a list of 99 ICSs previously identified.information was gathered from 81 sites out of the initially selected 99, reported by 45 participants from 27 Countries (82% of Countries in the ICSHNet). The predominant polluting activities were waste disposal (46%) and chemical industries (37%), affecting all environmental media, but more extensively surface and groundwater (70%) and soil (68%). Main categories of contaminants affecting different media were heavy metals and chlorinated hydrocarbons, but also BTEX (benzene, toluene, ethylbenzene, and xylene) and ambient air pollutants (e.g., particulate matter, SOx). Human health risk assessment was the most prevalent methodological approach for characterising impacts on health (32%), followed by epidemiological studies (26%), and health impact assessment (12%). The low reporting, both referring to data availability or methodologies, could be due to absence of data, or to the fact that the reporting person (many of them from the public health sector) did not know how to reach the environmental information.survey findings suggest that improving the collection and access to specific environmental, health and demographic data related to ICSs is crucial to meet the methodological requirement to better analyse the health impact of ICSs.

Communicating individual human biomonitoring results to study participants has been the subject of debate for some time. This debate is dominated by ethical considerations from a researchers' perspective on whether or not to communicate, thereby overlooking more practice-based questions from a participants' perspective on what and how to communicate. We conducted a small scale follow-up study based on eleven face-to-face interviews with mothers participating in the third cycle of the Flemish Environment and Health Study (FLEHS III 2012-2015) to investigate how they experienced and interpreted individual biomonitoring results. Key findings indicate that respondents were generally satisfied with participating in the biomonitoring study, but the report-back process especially lacked contextualized information and interactive communication options to better comprehend and cope with personal results. These findings also argue in favor of a more tailored approach in which report-back methods, formats and content are diversified according to the type of results and the preferences of participants. A reflexive research practice with active engagement in follow-up research is crucial to improve participants' understanding and use of personal biomonitoring results. Morrens, B (corresponding author), Univ Antwerp, Fac Social Sci, B-2000 Antwerp, Belgium. bert.morrens@uantwerpen.be; hans.jonker@uantwerpen.be; elly.denhond@provincieantwerpen.be; dries.coertjens@uantwerpen.be; ann.colles@vito.be; greet.schoeters@vito.be; nicolas.vanlarebeke@ugent.be; tim.nawrot@uhasselt.be; adrian.covaci@uantwerpen.be; vera.nelen@provincieantwerpen.be; frederic.vandermoere@uantwerpen.be; ilse.loots@uantwerpen.be

Sex hormone levels and timing of sexual maturation are considered important markers for health status of adolescents in puberty, and previous research suggests they might be influenced by metal exposure. In three campaigns of the Flemish Environment and Health Study (FLEHS I 2002–2006; FLEHS II 2007–2011 and FLEHS III 2012–2015), data were collected on internal exposure to metals (Cd, Cu, Pb, Cr, Mn, Tl, Ni, Sb, Hg, As and As species) and sexual maturation in 2671 14–15 years old adolescents. All metals were measured in blood and/or urine, except total- and methylmercury which were measured in hair samples. Sex hormone levels were measured in blood serum of adolescent males of the cohorts of FLEHS I and FLESH II. The use of a uniform methodology in successive campaigns allows to confirm associations between exposure and health in different cohorts and over time. Furthermore, mathematical and statistical density correction methods using creatinine or specific gravity were tested for urinary markers.Significant associations between sex hormones and maturity markers were observed in the FLEHS I and II campaigns, when both were assessed together. Regardless of the applied correction method, creatinine correction systematically introduced bias due to associations of creatinine with sex hormones and maturation markers, especially in adolescent males, while this is not the case for specific gravity. A series of exposure-response associations were found, but several involving Cd, Pb, As, Tl and Cu persisted in different FLEHS campaigns. The effects of Pb and Cu on luteinizing hormone, (free) testosterone, (free) oestradiol and maturation support a xenoestrogenic agonistic action on the feedback of oestradiol to the hypothalamus-pituitary-gonadal axis.Our results suggest that specific care should be taken when selecting urine density correction for investigating associations with hormonal and maturation markers in adolescent males. Furthermore, the possibility of xenoestrogenic effects of certain metals in environmentally exposed adolescents warrants further investigation. Keywords: FLEHS, Xenoestrogen, Exposure-response, Creatinine, Multiple regression, Metals

The Flemish Centre for Environment and Health started with human biomonitoring in 2002 (FLEHS I: 20022006). The main goal of the second human biomonitoring cycle (FLEHS II: 20072011), was to determine mean values for a large number of pollutants in a representative sample of the general Flemish population. Values for Cd and Pb were updated, and a group of previously undetermined metals and metalloids (As, Mn, Cu and Tl) were included in some of the age groups. In this human biomonitoring program, three different age groups of the general Flemish population were monitored: 255 newborns and their mothers, 210 adolescents aged 1415, and 204 adults between 20 and 40 years old. Trace elements were determined in cord blood and maternal blood of the mothers, in blood and urine of adolescents and in urine of adults. Determinants of life-style and personal factors were taken into account. The levels of trace elements in cord blood and maternal blood were for most elements at the lower end of the range found in literature. For Pb, As and Tl, a strong correlation (respectively r = 0.43, 0.55 and 0.33; p < 0.05) was found between levels in cord blood (respectively 8.6, 0.54 and 0.017 μg/L) and maternal blood (11.1, 0.64 and 0.028 μg/L), indicating that they are transported via the placenta from mother to fetus. The levels found in the adolescents and adults were compared with results from international biomonitoring studies, and were found to be in the same ranges. With the exception of Pb, all trace elements increased with increasing age group population. Finally, the results also showed that the levels of Cd and Pb in blood for this campaign (e.g. for Pb 8.6 and 14.8 μg/L in neonates and adolescents respectively) were lower compared to the first campaign (e.g. for Pb 14.7 and 21.7 μg/L in neonates and adolescents respectively), indicating a decrease over time. However, differences in sampling strategies might partially explain this observed trend.

Background: In 2007, the second cycle of the Flemish human biomonitoring survey started, with a main focus on 14–15 year-old adolescents. Objectives: The main objectives were generating reference values for exposure markers, determining the pollution pressure in industrial hotspots and establishing dose–effect relationships between exposure to pollutants and hormone levels, sexual development, asthma and allergy, genotoxic and hematological markers. Methods: Geometric means with 95% confidence intervals (CI) were calculated for a reference population of 200 14–15 year-old adolescents. Stepwise multiple regression analyses with correction for confounders and covariates were performed to establish dose–effect relationships. Results: Geometric mean concentrations (with 95% CI) of 49.6 (45.7, 53.8), 70.8 (63.6, 78.8) and 8.34 (7.76, 8.97) ng g−1 lipid for the sum of PCB 138, 153 and 180, p,p′-DDE and HCB were respectively 23%, 26% and 60% lower than those obtained five years earlier. Geometric mean concentrations of 108 (101, 114) and 32.1 (30.1, 34.2) pg CALUX-BEQ g−1 lipid were observed for the PCDD/Fs and dioxin-like PCBs, respectively. Multiple dose–effect relationships were observed between POPs and several effect markers, including positive (boys) and negative (girls) associations with data on sexual development and positive associations with asthma, animal allergy and free thyroxine (boys and girls). Conclusions: Our findings suggest that chlorinated POP concentrations are decreasing over time and that even relatively low concentrations are associated with biological effects. Keywords: Chlorinated POPs, FLEHS II, Dose–effect, Hormones, Human biomonitoring, Sexual development

How can we assess the quality of an analytical deliberative decision support procedure in environmental health practice? Objectifying quality criteria is difficult for several reasons. Opening up evaluation to a diversity of critics is one approach to take into account different actor perspectives and complexity. We describe how social scientists organized extended peer evaluation of a participatory multi-criteria procedure that was applied in Flemish environmental health practice. International peer review was combined with local extended peer evaluation. Social scientists collaborated closely with natural scientists and policy representatives in designing several evaluative activities and in interpreting the results.We discuss how these different perspectives came to reach conclusions, with a special focus on methodological decision-making. A process of learning by doing and negotiating, finding a methodological path amidst practicalities, complexity and ambition.

In this article we analyse how protests against wind farms reflect symbolic distances or alienations, typical to Flanders (Belgium), as consequences of wider societal trends. A thorough qualitative study of three wind farm projects in Flanders, including group discussions and interviews with crucial stakeholders, shows that the current siting process reinforces disagreements and leads to a stalemate between different framings of the wind farms. Using insights from our case studies and the literature, we argue for spatial planning which strives for a negotiation over acceptable solutions rather than acceptance of fixed proposals.

Background: Identification of determinants of exposure to pollutants can be a tool for targeted policy actions to reduce exposure. In the Flemish Environment and Health studies (FLEHS), biomonitoring data are coupled to questionnaires in order to identify significant determinants of exposure for the monitored pollutants. Objective: The aim of this study is to explore determinants of exposure to metals in adolescents, newborn-mother pairs and adults in the latest cycle of FLEHS (2012-2015). These determinants will be compared with results from the previous cycles (2002-2006, 2007-2011), to identify those that are consistent over the different campaigns of FLEHS. Part of the population exceeds existing health guidelines for internal exposure to cadmium (adults and adolescents) and arsenic (adolescents), so special focus is given to these metals. Furthermore, certain species of arsenic are considered separately, since the toxicity of arsenic heavily depends on its form. Methods: Pollutant concentrations in biological matrices like blood and urine are the cumulative reflection of all exposure. Statistical regression techniques are performed on the biomonitoring results in each study population to identify determinants of pollutants. Results: Some associations with significance in the latest cycle were consistent with earlier cycles. Like the positive association between blood and cord blood cadmium and smoking in adolescents and mothers respectively (p

Introduction Past and current industrial activities have left a legacy of areas contaminated by a mix of toxic substances. Studies conducted in such areas have provided relevant pieces of evidence,...

Background In Belgium, around 8.5% of the children have asthmatic symptoms. Increased asthma risk in children has been reported in relation to exposure to phthalate plasticizers but the underlying mechanisms are largely unknown. Aim The aim of this study was to identify if oxidative stress, assessed by excision of 8-hydroxydeoxyguanosine (8-OHdG) from damaged DNA, is an intermediate marker for the association between phthalate exposure and doctor-diagnosed asthma. Material and methods In 418 14–15-year-old youngsters, recruited as a representative sample of residents of Flanders (Belgium), personal exposure to phthalates was assessed by measuring phthalate metabolites in urine: mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP), mono-isobutyl phthalate (MiBP) and mono-ethyl phthalate (MEP). Analysis of 8-OHdG in urine was used as a sensitive biomarker of oxidative stress at the level of DNA. The presence of doctor-diagnosed asthma was elicited by a self-administered questionnaire. Associations were assessed using multiple linear and logistic regression models. Mediation was tested using Baron and Kenny's regression approach. Results A significant increased risk of a youngster being diagnosed with asthma was found for both urinary MnBP (metabolite of dibutyl phthalate (DBP)) and the sum of the three di(2-ethylhexyl) phthalate metabolites (ΣDEHP = MEHP + MEHHP + MEOHP), with respective odds ratio of 1.84 [95% CI: 1.02, 3.32] for MnBP and 1.94 [95% CI: 1.07, 3.51] for ΣDEHP. In addition, we observed significant associations between all urinary phthalate metabolites and increased urinary levels of 8-OHdG. The associations were stronger in girls than in boys. We did not found evidence that 8-OHdG was associated with doctor-diagnosed asthma. Conclusion The results of our study are in line with other findings from epidemiological surveys and raise further concern about DEHP and DBP as risk factors for asthma, however, the underlying mechanisms are not yet well understood.

Polycyclic aromatic hydrocarbons (PAHs) are of interest to human biomonitoring studies due to their carcinogenic potential. Traditionally metabolites of these compounds, like 1-hydroxypyrene, are monitored in urine, but recent methods allow the determination of the parent compounds in urine, which give additional information regarding sources and toxicity of PAHs. In order to assess the feasibility of incorporating these methods in a human biomonitoring study, the 16 USEPA parent PAHs were determined in 20 urine samples. These samples were obtained from 10 boys and 10 girls aged 1416 years, participating in the third Flemish Environment and Health Study (Flanders, Belgium). Of these 16 parent PAHs, nine could be determined in more than 95% of the samples and three (including benzo(a)pyrene) in more than 50%. Several correlations were found between different PAHs, but not between pyrene and its metabolite 1-hydroxypyrene. Diagnostic PAH ratios in urine and air samples pointed towards combustion sources and are in line with the ratios in environmental samples. Benzo(a)pyrene, naphthalene and fluorene have the highest carcinogenic potential in our cohort, when using toxic equivalency factors. Some associations between PAH congeners and determinants of exposure were found, while fluorene and acenaphthylene were positively associated with thyroid hormone levels and benzo(a)pyrene showed a positive correlation with DNA damage by comet assay. These results confirm that parent PAHs in urine are useful as biomarkers of exposure in biomonitoring studies.

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.

Introduction Traffic-related air pollution has been shown to induce neurotoxicity in rodents. Several recent epidemiological studies reported negative associations between residential outdoor air pollution and neurobehavioral performance. We investigated in a population of non-smoker adolescents the associations between the urinary concentration of trans, trans-muconic acid (t,t-MA-U), a metabolite of benzene and used as proxy-biomarker of traffic exposure, and two neurobehavioral domains, i.e. sustained attention and short-term memory. Methods In the framework of an environmental health surveillance study in Flanders (Belgium), we examined between 2008 and 2014 grade nine high school students (n=895). We used reaction time, number of omission errors, and number of commission errors in the Continuous Performance Test to evaluate sustained attention, and for the evaluation of short-term memory we used maximum digit span forward and backward of the Digit Span Test. We measured blood lead (PbB) to assess the independent effect of t,t-MA-U on neurobehavioral outcomes. Results This neurobehavioral examination study showed that a ten-fold increase in t,t-MA-U was associated with a 0.14 SD lower sustained attention (95% Confidence Interval: −0.26 to −0.019; p=0.02) and a 0.17 SD diminished short-term memory (95% CI: −0.31 to −0.030; p=0.02). For the same increment in t,t-MA-U, the Continuous Performance Test showed a 12.2 ms higher mean reaction time (95% CI: 4.86–19.5; p=0.001) and 0.51 more numbers of errors of omission (95% CI: 0.057–0.97; p=0.028), while no significant association was found with errors of commission. For the Digit Span Tests, the maximum digit span forward was associated with a 0.20 lower number of digits (95% CI: −0.38 to −0.026; p=0.025) and maximum digit span backward with −0.15 digits (95% CI: −0.32 to 0.022; p=0.088). These associations were independent of PbB, parental education and other important covariates including gender, age, passive smoking, ethnicity, urinary creatinine, time of the day, and examination day of the week. For PbB, an independent association was only found with mean reaction time of the Continuous Performance Test (19.1 ms, 95% CI: 2.43–35.8; p=0.025). Conclusions In adolescents, a ten-fold increase in the concentration of t,t-MA-U, used as a proxy-biomarker for traffic-related exposure, was associated with a significant deficit in sustained attention and short-term memory. The public health implications of this finding cannot be overlooked as the effect-size for these neurobehavioral domains was about 40% of the effect-size of parental education. The study was commissioned and financed by the Ministry of the Flemish Community (Department of Economics, Science and Innovation; Flemish Agency for Care and Health; and Department of Environment, Nature and Energy). This work was further supported by the European Research Council (Grant ERC-2012-StG 310898) and by the Flemish Scientific Fund (FWO) (Grant G.073315N). Michal Kicinski is a Ph.D fellow at the Research Foundation-Flanders (FWO).

Background: Environmental justice research suggests that inequalities in the distribution of environmental exposure to chemical pollution systematically disadvantage the lower social strata of society. The effects of these inequalities on the human exposure to pollution are however to a large extend unknown. The purpose of this study is to assess social gradients in human biomonitoring results of a representative sample of Flemish adolescents. Methods: We investigate the associations between individual socioeconomic status (SES), measured by parental educational attainments, and internal body concentration of seven chemical compounds in biological samples of 1642 adolescents aged 14–15 in Flanders (Belgium): PCBs, HCB, DDE, lead, cadmium, benzene and PAHs. Social gradients in average and high exposure to these biomarkers were examined with geometric means and odds ratios (with 95% confidence intervals), using multiple regression models, controlling for covariates and confounders. Results: Depending on the (type of) pollutant, adolescents with a lower SES either have higher or lower internal concentrations. Chlorinated compounds (PCBs and pesticides HCB and DDE) are positively associated with SES (higher exposures for higher SES), while heavy metals (lead and cadmium) are negatively associated (higher exposures for lower SES). For metabolites of organic compounds (benzene and PAHs) we find no association with SES. Socially constructed factors, such as dietary and lifestyle habits, play an important role in these relations. Conclusions: Our study suggests that the association between individual SES and the internal body concentration of exposure to environmental pollutants in Flemish adolescents is more complex than can be assumed on the basis of the environmental justice hypothesis. Flemish Government (Department of Science, Department of Public Health and Environment, Nature and Energy Department)

Within the Flemish Environment and Health stud- ies (FLEHS I, 2002-2006, and FLEHS II, 2007-2012), pes- ticide exposure, hormone levels and degree of sexual matura- tion were measured in 14-15-year-old adolescents residing in Flanders (Belgium). In FLEHS II, geometric mean concentra- tions (with 95 % confidence interval (CI)) of 307 (277-341) and 36.5 ng L �1 (34.0-39.2) were found for p,p'- dichlorophenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB). These values were respectively 26 and 60 % lower than levels in FLEHS I, 5 years earlier. Metabolites of organophosphorus pesticides (OPPs) and of para-dichlorobenzene were measured for the first time in FLEHS II, yielding concentrations of 11.4, 3.27 and 1.57 μ gL �1 for the sum of dimethyl- and diethyl phosphate metabolites and 2,5-dichlorophenol (2,5-DCP), respectively. Data on internal exposure of HCB showed a positive correla- tion with sexual maturation, testosterone and the aromatase index for boys and with free thyroxine (fT4) and thyroid stimulating hormone (TSH) (both boys and girls). For both p,p'-DDE and HCB, a negative association with sexual devel- opment in girls was found. The OPP metabolites were nega- tively associated with sex hormone levels in the blood of boys and with sexual maturation (both boys and girls). The pesti- cide metabolite 2,5-DCP was negatively correlated with free T4, while a positive association with TSH was reported (boys and girls). These results show that even exposure to relatively low concentrations of pesticides can have significant influ- ences on hormone levels and the degree of sexual maturation in 14-15-year-old adolescents.

As part of the second Flemish Environment and Health Study (FLEHS II), bisphenol-A (BPA) and different phthalate metabolites were analyzed, for the first time, in the urine of 210 adolescents in Flanders, Belgium. All chemicals had a detection frequency above 90%. For all compounds, except the sum of DEHP, highest levels were detected during spring. Average values for the Flemish adolescents were in an agreement with concentrations found in different international studies, all confirming the ubiquity of BPA and phthalate exposure. There was a significant correlation between BPA and the different phthalate metabolites (r between 0.26 and 039; p < 0.01). Shared sources of exposure to BPA and phthalates, such as food packaging, were suggested to be responsible for this positive correlation. Different determinants of exposure were evaluated in relation to the urinary concentrations of these chemicals. For BPA, a significant association was observed with household income class, smoking and exposure to environmental tobacco smoke. For phthalates, the following significant associations were observed: age (MBzP), educational level of the adolescent (MBzP), equivalent household income (MnBP), use of personal care products (MnBP and MBzP), wall paper in house (MnBP and MBzP) and use of local vegetables (MnBP and MBzP). (C) 2014 Elsevier Inc. All rights reserved.

In the Flemish human biomonitoring programme FLEHS II (2007-2011) trace metals (Cd, Pb, Cr, Ni, Cu, Mn, TI, Sb, As and toxic relevant arsenic) were analysed in the blood and urine of adolescents (14-15 years old) in the reference population in Flanders and in areas of important industrial activities: Genk-Zuid and Menen. After adjustment of the results for confounding factors, the adolescents living in Genk-Zuid had higher levels of Cr, Cu and TI in blood, higher levels of Cd and toxic relevant arsenic (TRA) in urine, but lower levels of Ni in blood and Sb in urine compared to the reference population. In Menen higher levels of Cd and Cu in urine, higher concentrations of TI in blood but lower concentrations of Pb in blood and lower Ni, Sb and As in urine were found compared to the reference population. For both the reference population and the hot spots the concentrations are within the ranges found in other countries. Compared to the previous biomonitoring programme FLEHS 1(2002-2006) a decrease in the concentrations of Cd and especially of Pb in blood was observed. However, it cannot be excluded that differences between the two campaigns are partially due to different sampling strategies. (c) 2013 Elsevier GmbH. All rights reserved.

Due to possible health risks, quantification of mercury accumulation in humans was included in the Flem-ish biomonitoring programmes FLEHS I (20022006) and FLEHS II (20072011). The general objectiveof FLEHS I was to assess regional exposure levels in order to link possible differences in these internalexposure levels to different types of local environmental pressure. Therefore, Hg and MMHg (methylmer-cury) were only measured in pooled blood samples per region and per age class. In FLEHS II, mercuryconcentrations were measured in hair of each participant. About 200 adolescents and 250 mothers (ref-erence group) and two times 200 adolescents (2 hotspots) were screened. The main objectives of theFLEHS II study were: (1) to determine reference levels of mercury in hair for Flanders; (2) to assess rela-tions between mercury exposure and possible sources like fish consumption; (3) to assess doseeffectrelations between mercury exposure and health effect markers. The results showed that mercury con-centrations in the Flemish population were rather low compared to other studies. Mercury levels in theFlemish populations were strongly related to the age of the participants and consumption of fish. Signif-icant negative associations were observed between mercury in hair and asthma, having received breastfeeding as a newborn, age at menarche in girls, allergy for animals and free testosterone levels. Significantcorrelations were also observed between mercury in hair and genes JAK2, ARID4A, Hist1HA4L (boys) andHLAdrb5, PIAS2, MANN1B1, GIT and ABCA1 (girls).

Environmental justice research suggests that inequalities in the distribution of environmental quality systematically disadvantage the lower social strata of society. The effects of these inequalities on the human exposure to specific chemical pollution remain, however, to a large extend unknown, especially in hotspot areas where surrounding neighbourhoods are exposed to a mixture of diverse pollution. In Flanders, the northern part of Belgium, a community-based participatory approach was set up between 2009-2010 to collect blood, urine and hair samples of 197 socially and ethnically diverse adolescents (14-15 years of age) living in the close proximity of a non-ferro industrial area. We conduct a socio- stratification of human biomonitoring results by associating the internal body concentration of three types of chemical pollution (heavy metals, POPs and volatile compounds) with individual socioeconomic status (SES) and ethnic background. Social gradients in exposure to these chemicals are assessed with geometric means, using multiple regression models, controlling for covariates and confounders. Our results show that, depending on the (type of) pollutant, adolescents with a lower SES can either have higher or lower internal concentrations. Socially constructed factors, such as dietary and lifestyle habits, play an important role in these relations. We conclude that when assessing the human exposure concentrations of pollutants, more complex patterns of social stratification emerge than can be assumed on the basis of the environmental justice hypothesis. It therefore remains important to consider the chemical environment in relation to the social environment when monitoring environmental health risks. By emphasising on transparent communication and relevant interaction between residents, local stakeholders and scientists, monitoring environmental health could enhance the empowerment of socioeconomically disadvantaged communities.

Personal care products (PCPs), such as soaps, perfumes, cosmetics, lotions, etc., contain a variety of chemicals that have been described as potentially hormone disrupting chemicals. Therefore, it is important to assess the internal exposure of these chemicals in humans. Within the 2nd Flemish Environment and Health Study (FLEHS II, 2007–2011), the human exposure to three classes of pollutants that are present in a wide variety of PCPs – i.e. polycyclic musks (galaxolide, HHCB and tonalide, AHTN in blood), parabens (urinary para -hydroxybenzoic acid, HBA) and triclosan (urinary TCS) – was assessed in 210 Flemish adolescents (14–15 years) and in 204 adults (20–40 years) randomly selected from the general population according to a stratified two stage clustered study design. The aim of this study was to define average levels of exposure in the general Flemish population and to identify determinants of exposure. Average levels (GM (95% CI)) in the Flemish adolescents were 0.717 (0.682–0.753) μg/L for blood HHCB; 0.118 (0.108–0.128) μg/L for blood AHTN; 1022 (723–1436) μg/L for urinary HBA and 2.19 (1.64–2.92) μg/L for urinary TCS. In the adults, levels of HBA were on average 634 (471–970) μg/L. Inter-individual variability was small for HHCB and AHTN, intermediate for HBA, and large for TCS. All biomarkers were positively associated with the use of PCPs. Additionally, levels of HHCB and AHTN increased with higher educational level of the adolescents. Both in adults and adolescents, urinary HBA levels were negatively correlated with BMI. We define here Flemish exposure values for biomarkers of PCPs, which can serve as baseline exposure levels to identify exposure trends in future biomonitoring campaigns.