Exposure levels, determinants and risk assessment of organophosphate flame retardants and plasticizers in adolescents (14-15 years) from the Flemish Environment and Health Study

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 (F_UE) 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.

Arsenic speciation in fish and shellfish from the North Sea (Southern bight) and Açu Port area (Brazil) and health risks related to seafood consumption

In North Sea and Port Açu (Brazil) coastal areas, high arsenic (As) concentrations were observed in water, soil and sediments. Therefore, the impact of this contamination on fish and shellfish species bought from local fishermen was studied. Total As was assessed with ICP-OES (Brazil) and ICP-MS (North Sea) after microwave digestion. Toxic As was assessed with liquid chromatography-ICP-MS (Brazil) and hydride generation-atomic fluorescence spectrometry (North Sea). All analytical methods comply with Quality Assurance/Quality Control procedures. Several fish species have average Total As concentrations above 1 μg g-1 wet weight (ww), but the highest concentrations are found in less spotted dogfish, lemon sole and whelks from the North Sea, with respectively 50, 49 and 50 μg g-1 ww. High Total As concentrations correspond to high Toxic As concentrations, except for scallops having increased Toxic As concentrations. Toxic As fractions are highest in scallops (almost 10%) but rarely exceeds 2% in all other species. Liver samples were only analyzed in ray, dogfish and catfish and their Toxic As fractions are between 2 and 4 times higher than in muscle. For a consumption of 150 g of seafood, only 3 samples exceed the provisional total daily intake of 2 μg kg-1 bw, however, cancer risks are non-negligible. Using mean Toxic As concentrations for each of the different fish and shellfish species studied, Lifetime Cancer Risk values at the actual global seafood consumption rate of 54 g day-1 are above 10-4 for whelks, scallops, dogfish, ray and lemon sole.

Human exposure to endocrine disrupting chemicals and fertility: A case-control study in male subfertility patients

BACKGROUND

Dioxins, PCBs, chlorinated pesticides, brominated flame retardants, bisphenol A, triclosan, perfluorinated compounds and phthalates are known as endocrine disrupting chemicals (EDCs).

OBJECTIVES

The aim of our study was to investigate whether higher exposure to EDCs is associated with increased subfertility in men.

METHODS

We measured biomarkers of exposure in 163 men, recruited through four fertility clinics. According to WHO guidelines, we used a total motility count (TMC) of 20 million as cut-off value. We assigned patients to the case group when two semen samples - collected at least one week apart - had a TMC<20 and to the control group when both samples had a TMC≥20. To estimate the risk of subfertility and alteration in sex hormone concentrations we used multivariable-adjusted analysis, using logistic and linear regressions, respectively.

RESULTS

For an IQR increase in serum oxychlordane, the odds ratio for subfertility was 1.98 (95% CI: 1.07; 3.69). Furthermore, men with serum levels of BDE209 above the quantification limit had an odds of 7.22 (1.03; 50.6) for subfertility compared with those having values below the LOQ. Urinary levels of phthalates and triclosan were negatively associated with inhibin B and positively with LH. Urinary bisphenol A correlated negatively with testosterone levels.

CONCLUSIONS

Our study in men showed that internal body concentrations of endocrine disrupting chemicals are associated with an increased risk of subfertility together with alterations in hormone levels. The results emphasize the importance to reduce chemicals in the environment in order to safeguard male fertility.

Internal exposure to organochlorine pollutants and cadmium and self-reported health status: a prospective study

In this paper, based on the Flemish biomonitoring programs, we describe the associations between internal exposure to organochlorine pollutants and to cadmium (measured in 2004-2005 for adults aged 50-65 years) and self-reported health status obtained through a questionnaire in November 2011. Dioxin-like activity in serum showed a significant positive association with risk of cancer for women. After adjustment for confounders and covariates, the odds ratio for an exposure equal to the 90th percentile was 2.4 times higher than for an exposure equal to the 10th percentile. For both men and women dioxin-like activity and serum hexachlorobenzene (HCB) showed a significant positive association with risk of diabetes and of hypertension. Detailed analysis suggested that an increase in BMI might be part of the mechanism through which HCB contributes to diabetes and hypertension. Serum dichlorodiphenyldichloroethylene (p,p'-DDE) concentration showed a significant positive association with diabetes and hypertension in men, but not in women. Serum polychlorinated biphenyl (PCB) 118 showed a significant positive association with diabetes in both men and women, and after adjustment for correlated exposures, also with hypertension in men. Urinary cadmium concentrations showed a significant positive association with hypertension. Urinary cadmium concentrations were (in 2004-2005) significantly higher in persons who felt in less than good health (in 2011) than in persons who felt in very good health. After adjustment for correlated exposures (to HCB, p,p'-DDE and PCB118) marker PCBs showed a significant negative association with diabetes and hypertension. Serum p,p'-DDE showed in men a significant negative association with risk of diseases based on atheromata. Our findings suggest that exposure to pollutants can lead to an important increase in the risk of diseases such as cancer, diabetes and hypertension. Some pollutants may possibly also decrease the risk of some health problems, although this requires confirmation by other approaches.

Determinants of bisphenol A and phthalate metabolites in urine of Flemish 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 0.39; 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).

Prenatal exposure to environmental contaminants and behavioural problems at age 7-8years

Animal studies showed that the developing brain is particularly sensitive to chemical exposure. Human studies carried out in areas with high exposures have proven neurodevelopmental disorders in relation to e.g. lead and PCBs. Whether these chemicals are associated with behavioural problems in childhood at current environmental levels is not well known. Therefore, we assessed the association between prenatal exposure to lead, cadmium, PCBs, dioxin-like compounds, HCB and p,p'-DDE and behavioural problems in 7-8year old children. Prenatal exposure data were obtained from the Flemish mother-new-born cohort. Lead, cadmium, PCBs, dioxin-like compounds, HCB and p,p'-DDE were analysed in cord blood. When the child reached 7-8years, 270 mothers completed the Strengths and Difficulties Questionnaire assessing their children's behavioural health. We found that doubling the prenatal lead exposure (cord blood lead levels) was associated with a 3.43 times higher risk for hyperactivity in both boys and girls. In addition, total difficulties were 5.08 times more likely in the highest tertile for prenatal lead exposure compared to the lowest tertile. In girls, total difficulties were 4.92 more likely when doubling cord blood p,p'-DDE, whereas no significant association was found in boys. Further, we noted in boys a 1.53 times higher risk for emotional problems when doubling cord blood cadmium, whereas no significant association was found in girls. These results indicate that the presence of environmental contaminants influences the mental health of the next generation.

Opening the research agenda for selection of hot spots for human biomonitoring research in Belgium: a participatory research project

BACKGROUND

In order to select priority hotspots for environment and health research in Flanders (Belgium), an open procedure was organized. Environment and health hotspots are strong polluting point sources with possible health effects for residents living in the vicinity of the hot spot. The selection procedure was part of the work of the Flemish Centre of Expertise for Environment and Health, which investigates the relation between environmental pollution and human health. The project is funded and steered by the Flemish government.

METHODS

The involvement of other actors than merely experts is inspired by the 'analytical-deliberative' approach of the National Research Council in the United States and the extended peer community approach. These approaches stress the importance of involving different expert- and social perspectives in order to increase the knowledge base on complex issues. In the procedure used in the project a combination of expert and stakeholder input was essential. The final decision was supported by a multi-criteria analysis of expert assessment and stakeholder advice.

RESULTS

The endeavour was challenging from the start because of the complicated ambition of including a diversity of actors, potential hotspots, concerns and assessment criteria, but nevertheless the procedure proved its value in both structuring and informing the decision-making process. Moreover the process gained the support of most actors participating in the process, even though the final selection could not satisfy all preferences.

CONCLUSIONS

Opening the research agenda exemplifies the value of inter- and transdisciplinary cooperation as well as the need for a well-structured and negotiated procedure that combines relevant factors and actors with pragmatism. The value of such a process also needs to prove itself in practice after the procedure has been completed: the tension between an ambition of openness on the one hand and a more closed attitude amongst experts on the other will continue to play a role even after closure.

The relation between the estimated dietary intake of PCDD/Fs and levels in blood in a Flemish population (50-65 years)

Dioxin-like activity was measured in the serum of 1425 Flemish men and women via the CALUX assay. The adults, aged between 50 and 65 years, participated in a large biomonitoring program, executed by the Flemish Center of Expertise for Environment and Health between 2002 and 2006. Within the context of this biomonitoring program also dietary intake of dioxin-like contaminants was assessed through a food frequency questionnaire. The relation between the estimated dietary intake and the dioxin-like activity in serum was evaluated using multivariate analyses: a logistic model was performed on the total population, while a linear regression analysis was done on the subsample with quantifiable dioxin activity levels in serum. Region, gender, age, BMI, smoking status, as well as dietary habits were entered in the model, with dioxin level as an outcome estimate. Both the logistic and linear model confirmed the contribution of dietary intake to the dioxin activity measured in serum. Also BMI and region were found to be associated with dioxin activity levels.