Spatial and temporal variations of currently used pesticides (CUPs) concentrations in ambient air in Wallonia, Belgium.

Pesticides are among the most widely used chemicals thus contributing to a global contamination of the environment. Studies in North America and Europe have reported ambient air concentrations of Currently Used Pesticides in rural and urban locations as well as in remote areas. Monitoring pesticides in air is required for a better understanding of human exposure through inhalation and to assess potential health effects related to this exposure pathway. In this study, 46 pesticides were analyzed in ambient air in sampling stations distributed over Wallonia during a year, from May 2015 to May 2016. Different typologies were defined for sampling sites (remote areas, urban sites, agricultural sites, livestock area, and sites with other professional uses). Ambient air was sampled for 14 days with an active air sampler at a flow rate of 4 m³/h. Quartz filters and PUF/XAD-2/PUF cartridges were used to sample both gas and particulate phase pesticides. On the 46 pesticides studied, 6 insecticides, 18 herbicides and 18 fungicides were detected. Herbicides were measured in 68.3% of samples throughout the year, whereas fungicides and insecticides were measured in 62.6% and 13.2% of the samples, respectively. The highest mean concentrations for all pesticides were measured in spring-summer, whereas few pesticides were measured at low concentrations in winter. Six pesticides were measured in the remote sampling station at lower concentrations than in all other sites highlighting volatility of these pesticides. The highest number of different pesticides and the highest concentrations were measured in agricultural stations, where uses of plant protection products are higher. Finally, less volatile pesticides were only detected near application areas and at low concentrations. Together, these results provide better insight on the spatial and temporal variations of pesticides concentrations in ambient air, which were related to pesticides uses as well to atmospheric volatility and persistence.

Assessment of children's exposure to currently used pesticides in wallonia, Belgium.

In spring 2016, a study was carried out to characterize currently used pesticide (CUP) exposure among children living in Wallonia (Belgium). Pesticides were measured in both first morning urine voids of 258 children aged from 9 to 12 years and in ambient air collected close to the children's schools. Out of the 46 pesticides measured in the air, 19 were detected with frequencies varying between 11 % and 100 %, and mean levels ranging from <0.04 to 2.37 ng/m³. Only 3 parent pesticides were found in 1-10% of the urine samples, while all the metabolites analyzed were positively detected at least once. The captan metabolite (THPI) was quantified in 23.5 % of the samples, while 3,5,6-trichloro-2-pyridinol (chlopryrifos metabolite) was detected in all urines with levels ranging from 0.36-38.96 µg/l. 3-phenoxybenzoic acid (3-PBA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (t-DCCA) and diethylphosphate were the most abundant pyrethroid metabolites and dialkylphosphate measured. The air inhalation was demonstrated to be a minor route of exposure for the selected CUPs. Statistical regressions highlighted predictors of exposure for some pesticides such like consumption of grey bread, presence of carpets at home or indoor use of pesticides, although no clear source was identified for most of them.

Associations of plasma concentrations of dichlorodiphenyldichloroethylene and polychlorinated biphenyls with prostate cancer: a case-control study in Guadeloupe (French West Indies).

BACKGROUND: Long-term exposure to persistent pollutants with hormonal properties (endocrine-disrupting chemicals; EDCs) may contribute to the risk of prostate cancer (PCa). However, epidemiological evidence remains limited. OBJECTIVES: We investigated the relationship between PCa and plasma concentrations of universally widespread pollutants, in particular p,p'-dichlorodiphenyl dichloroethene (DDE) and the non-dioxin-like polychlorinated biphenyl congener 153 (PCB-153). METHODS: We evaluated 576 men with newly diagnosed PCa (before treatment) and 655 controls in Guadeloupe (French West Indies). Exposure was analyzed according to case-control status. Associations were assessed by unconditional logistic regression analysis, controlling for confounding factors. Missing data were handled by multiple imputation. RESULTS: We estimated a significant positive association between DDE and PCa [adjusted odds ratio (OR) = 1.53; 95% CI: 1.02, 2.30 for the highest vs. lowest quintile of exposure; p trend = 0.01]. PCB-153 was inversely associated with PCa (OR = 0.30; 95% CI: 0.19, 0.47 for the highest vs. lowest quintile of exposure values; p trend < 0.001). Also, PCB-153 was more strongly associated with low-grade than with high-grade PCa. CONCLUSIONS: Associations of PCa with DDE and PCB-153 were in opposite directions. This may reflect differences in the mechanisms of action of these EDCs; and although our findings need to be replicated in other populations, they are consistent with complex effects of EDCs on human health.

Bioaccumulation of polybrominated diphenyl ethers (PBDEs) in Gammarus pulex: relative importance of different exposure routes and multipathway modeling.

Characterizing the exposure routes of an organism and its ability to regulate accumulated contaminants is a crucial step toward developing a biomonitor. To date, very little data are available on the bioaccumulation kinetics of PBDEs in freshwater biota. This study aims at investigating the potential use of a litter-degrader widely distributed in European freshwaters, Gammarus pulex, as an indicator of exposure to PBDEs. In aquatic microcosms, gammarids were exposed to a mixture of brominated congeners (BDE-28, 47, 66, 85, 99, 100, 153, 154 and 183) to assess their ability to bioconcentrate PBDEs. Results show that all tested congeners are highly internalized by G. pulex and uptake rates of PBDEs are closely related to their partition coefficients (Kow). The determination of the elimination rate of BDE-47, the congener most readily accumulated by gammarids, indicated that metabolism and excretion of this congener are low in G. pulex, which argues in favor of its use as a quantitative biomonitor. Finally, bioaccumulation experiments were performed using contaminated leaves to determine the relative importance of dietary uptake in the contamination of gammarids. Even though water is the preeminent exposure route, a significant uptake of BDE-47 through food was observed (27%). We propose a biodynamic model that takes into account both exposure routes to describe BDE-47 bioaccumulation. This study supports the use of this ubiquitous amphipod as an early warning monitor of the bioavailable contamination of freshwaters by PBDEs.

Investigating apical adverse effects of four endocrine active substances in the freshwater gastropod Lymnaea stagnalis.

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active substances (EASs). Up to now, only a few putative EASs have been tested for their reproductive toxicity in this species. In this study, we investigate the effects of four EASs with different affinities to the vertebrate estrogen and androgen receptors (chlordecone as an estrogen; cyproterone acetate, fenitrothion and vinclozolin as anti-androgens) on the reproduction of L. stagnalis in a 21-day semi-static test. Testosterone and 17α-ethinylestradiol (EE2) were used as the reference compounds. The tested EASs had no significant effect on growth and survival at the tested concentration ranges (ng to µg/L). Classical reproduction endpoints (i.e., oviposition and fecundity) were not responsive to the tested chemicals, except for chlordecone and 17α-ethinylestradiol, which hampered reproduction from 19.6 µg/L and 17.6 µg/L, respectively. The frequency of polyembryonic eggs, used as an additional endpoint, demonstrated the effects of all compounds except EE2. The molecular pathways, which are involved in such reproduction impairments, remain unknown. Our results suggest that egg quality is a more sensitive endpoint as compared to other reproductive endpoints commonly assessed in mollusk toxicity tests.

Proteomic analysis of the reproductive organs of the hermaphroditic gastropod Lymnaea stagnalis exposed to different endocrine disrupting chemicals.

Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range) of endocrine disrupting chemicals (EDCs). However, the mechanisms of action of these molecules on molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins, metallothioneins, GST, EROD). In this study we have investigated the impacts of four chemicals, which exhibit different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The 2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 µg/L of chlordecone increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive pathways (e.g., ovipostatin and yolk ferritin) could constitute relevant evidence of interaction of EDCs with reproductive pathways that are under the control of the endocrine system of L. stagnalis.

Esterification of vertebrate like steroids in molluscs: a target of endocrine disruptors?

Alterations of the reproductive organs of gastropod molluscs exposed to pollutants have been reported in natural populations for more than 40 years. In some cases, these impacts have been linked to exposure to endocrine-disrupting chemicals (EDCs), which are known to induce adverse impacts on vertebrates, mainly by direct binding to steroid receptors or by altering hormone synthesis. Investigations on the mechanisms of action of endocrine disruptors in molluscs show that EDCs induce modifications of endogenous titres of androgens (e.g., testosterone, androstenedione) and oestrogens (e.g., 17ß-oestradiol). Alterations of the activity of enzymes related to steroid metabolism (i.e., cytochrome P-450 aromatase, acyltransferases) are also often observed. In bivalves and gastropods, fatty acid esterification of steroids might constitute the major regulation of androgen and oestrogen homeostasis. The present review indicates that metabolism of steroid hormones to fatty acid esters might be a target of synthetic EDCs. Alterations of this process would impact the concentrations of free, potentially bioactive, form of steroids.

Persistent organochlorine pollutants with endocrine activity and blood steroid hormone levels in middle-aged men.

BACKGROUND: Studies relating long-term exposure to persistent organochlorine pollutants (POPs) with endocrine activities (endocrine disrupting chemicals) on circulating levels of steroid hormones have been limited to a small number of hormones and reported conflicting results. OBJECTIVE: We examined the relationship between serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulphate, androstenedione, androstenediol, testosterone, free and bioavailable testosterone, dihydrotestosterone, estrone, estrone sulphate, estradiol, sex-hormone binding globulin, follicle-stimulating hormone, and luteinizing hormone as a function of level of exposure to three POPs known to interfere with hormone-regulated processes in different way: dichlorodiphenyl dichloroethene (DDE), polychlorinated biphenyl (PCB) congener 153, and chlordecone. METHODS: We collected fasting, morning serum samples from 277 healthy, non obese, middle-aged men from the French West Indies. Steroid hormones were determined by gas chromatography-mass spectrometry, except for dehydroepiandrosterone sulphate, which was determined by immunological assay, as were the concentrations of sex-hormone binding globulin, follicle-stimulating hormone and luteinizing hormone. Associations were assessed by multiple linear regression analysis, controlling for confounding factors, in a backward elimination procedure, in multiple bootstrap samples. RESULTS: DDE exposure was negatively associated to dihydrotestosterone level and positively associated to luteinizing hormone level. PCB 153 was positively associated to androstenedione and estrone levels. No association was found for chlordecone. CONCLUSIONS: These results suggested that the endocrine response pattern, estimated by determining blood levels of steroid hormones, varies depending on the POPs studied, possibly reflecting differences in the modes of action generally attributed to these compounds. It remains to be investigated whether this response pattern is predictive of the subsequent occurrence of disease.

Testosterone levels and fecundity in the hermaphroditic aquatic snail Lymnaea stagnalis exposed to testosterone and endocrine disruptors.

Endocrine disruptors are known to alter endogenous free and esterified levels of androgenic and estrogenic steroid hormones in aquatic mollusks. The origin of steroids in these animals, however, remains controversial. In the present study, free and esterified testosterone concentrations were measured in the hermaphroditic aquatic gastropod Lymnaea stagnalis exposed to molecules known for their androgenic (testosterone and tributyltin), anti-androgenic (cyproterone-acetate), and estrogenic (chlordecone) properties, by reference to their mode of action in vertebrates. In parallel, snail oviposition and fecundity were followed over a 21-d exposure period. Testosterone exposure resulted in increased esterified testosterone levels, whereas free testosterone concentrations remained stable. In contrast, cyproterone-acetate significantly increased the free form of testosterone with no changes in the esterified form, whereas chlordecone showed a tendency to reduce (though not significantly) esterified testosterone concentrations without changing free testosterone levels. Finally, tributyltin did not alter testosterone homeostasis. The production of egg clutches and eggs was significantly reduced only in the snails exposed to the highest concentrations of chlordecone (19.6 µg/L) and tributyltin (94.2 ng Sn/L). Overall, the present study demonstrates that uptake of testosterone from the exposure medium occurs in L. stagnalis. Moreover, it shows that cyproterone-acetate and, to a lesser extent, chlordecone can alter endogenous testosterone levels in this freshwater snail. However, the relationship between hormonal changes and snail reproduction has not been established. Environ Toxicol Chem 2013;32:1740-1745. © 2013 SETAC.

Reproductive impacts of tributyltin (TBT) and triphenyltin (TPT) in the hermaphroditic freshwater gastropod Lymnaea stagnalis.

Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment, they have mainly been tested separately for their effects on snail reproduction. Because large discrepancies in experimental conditions occurred in these tests, the present study aimed to compare the relative toxicity of TBT and TPT under similar laboratory conditions in the range of 0 ng Sn/L to 600 ng Sn/L. Tests were performed on the simultaneous hermaphrodite Lymnaea stagnalis, a freshwater snail in which effects of TPT were unknown. Survival, shell length, and reproduction were monitored in a 21-d semistatic test. Frequency of abnormal eggs was assessed as an additional endpoint. Triphenyltin hampered survival while TBT did not. Major effects on shell solidity and reproduction were observed for both compounds, reproductive outputs being more severely hampered by TBT than by TPT. Considering the frequency of abnormal eggs allowed increasing test sensitivity, because snail responses to TBT could be detected at concentrations as low as 19 ng Sn/L. However, the putative mode of action of the 2 compounds could not be deduced from the structure of the molecules or from the response of apical endpoints. Sensitivity of L. stagnalis to TBT and TPT was compared with the sensitivity of prosobranch mollusks with different habitats and different reproductive strategies.

Chlordecone exposure and risk of prostate cancer.

PURPOSE: Determining whether environmental estrogens are associated with the risk of prostate cancer may have important implications for our general understanding of this disease. The estrogenic insecticide chlordecone was used extensively in the French West Indies, contaminating the population for more than 30 years. We analyzed the relationship between exposure to chlordecone and the risk of prostate cancer. PATIENTS AND METHODS: We investigated 623 men with prostate cancer and 671 controls. Exposure was analyzed according to case-control status, using either current plasma concentration or a cumulative exposure index based on years of exposure. We genotyped two single-nucleotide polymorphisms (rs3829125 and rs17134592) in the gene encoding chlordecone reductase. RESULTS: We found a significant increase in the risk of prostate cancer with increasing plasma chlordecone concentration (odds ratio [OR], 1.77; 95% CI, 1.21 to 2.58 for the highest tertile of values above the limit of detection [LD]; P trend = .002) and for cumulative exposure index (OR, 1.73; 95% CI, 1.04 to 2.88 for the highest quartile; P trend = .004). Stronger associations were observed among those with a positive family history of prostate cancer and among those who had lived in a Western country. The rs3829125 and rs17134592 allele variants were in complete linkage disequilibrium and were found at low frequency (0.04). Among subjects with plasma chlordecone concentrations above the LD, carriers of the allele variants had a higher risk of prostate cancer (OR, 5.23; 95% CI, 0.82 to 33.32). CONCLUSION: These findings support the hypothesis that exposure to environmental estrogens increases the risk of prostate cancer.

Pesticide exposure of pregnant women in Guadeloupe: ability of a food frequency questionnaire to estimate blood concentration of chlordecone.

CONTEXT: Chlordecone, an environmentally persistent organochlorine insecticide used intensively in banana culture in the French West Indies until 1993, has permanently polluted soils and contaminated foodstuffs. Consumption of contaminated food is the main source of exposure nowadays. We sought to identify main contributors to blood chlordecone concentration (BCC) and to validate an exposure indicator based on food intakes. MATERIAL AND METHODS: We used a food frequency questionnaire (FFQ) completed by a sample of 194 pregnant women to estimate their dietary exposure to chlordecone and compared it to blood levels. In a first approach, chlordecone daily intake was estimated as the product of daily eaten quantity of 214 foodstuffs, multiplied by their chlordecone content, and summed over all items. We then predicted individual blood chlordecone concentration with empirical weight regression models based on frequency of food consumption, and without contamination data. RESULTS: Among the 191 subjects who had BCC determination, 146 (76%) had detectable values and mean BCC was 0.86 ng/mL (range < LOD-13.2). Mean per capita dietary intake of chlordecone was estimated at 3.3 microg/day (range: 0.1-22.2). Blood chlordecone levels were significantly correlated with food exposure predicted from the empirical weight models (r=0.47, p<0.0001) and, to a lesser extent, with chlordecone intake estimated from food consumption and food contamination data (r=0.20, p=0.007). Main contributors to chlordecone exposure included seafood, root vegetables, and Cucurbitaceous. CONCLUSION: These results show that the Timoun FFQ provides valid estimates of chlordecone exposure. Estimates from empirical weight models correlated better with blood levels of chlordecone than did estimates from the dietary intake assessment.