Bruno Veyrand

PFOS (perfluorooctanesulfonate) in serum is negatively associated with testosterone levels, but not with semen quality, in healthy men

STUDY QUESTIONnIs exposure to perfluorinated compounds (PFCs) associated with testicular function (reproductive hormone levels and semen quality) in healthy men?nnnSUMMARY ANSWERnPFOS levels were significantly negatively associated with serum testosterone (total and calculated free), but not with any other reproductive hormones or semen quality.nnnWHAT IS KNOWN ALREADYnIn animals, some PFCs have endocrine disrupting potential, but few studies have investigated PFCs in relation to human testicular function. Previously, we and others have observed a negative association between serum PFC levels and sperm morphology. The potential associations with reproductive hormones remain largely unresolved.nnnSTUDY DESIGN, SIZE, DURATIONnA cross-sectional study of 247 men was conducted during 2008-2009.nnnPARTICIPANTS/MATERIALS, SETTING, METHODSnHealthy men from the general population, median age of 19 years, gave serum and semen samples. Serum samples were analysed for total testosterone (T), estradiol (E), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and inhibin-B and 14 PFCs, including perfluorooctanesulfonate (PFOS). Semen samples were analysed according to the WHO criteria.nnnMAIN RESULTS AND THE ROLE OF CHANCEnPFOS levels were negatively associated with testosterone (T), calculated free testosterone (FT), free androgen index (FAI) and ratios of T/LH, FAI/LH and FT/LH. Other PFCs were found at lower levels than PFOS and did not exhibit the same associations. PFC levels were not significantly associated with semen quality. PFOS levels in these samples collected in 2008-2009 were lower than in our previous study of men participating in 2003.nnnLIMITATIONS, REASONS FOR CAUTIONnResults were robust to adjustment for relevant confounders; however, the possibility of chance associations due to multiple testing or effects of uncontrolled confounding cannot be ruled out.nnnWIDER IMPLICATIONS OF THE FINDINGSnOur previous findings of decreased sperm morphology in the most highly PFC exposed men were not replicated, possibly due to a lack of highly exposed individuals; however, a recent independent study also did corroborate such an inverse association. The negative association between serum PFOS and testosterone indicates that testosterone production may be compromised in individuals with high PFOS exposure.nnnSTUDY FUNDING/COMPETING INTEREST(S)nThe authors received financial support from the European Commission (DEER, FP7-2007-212844), the Danish Agency for Science, Technology and Innovation (grant nos. 27107068 and 09-067180), Rigshospitalet (grant no. 961506336), the University of Copenhagen, the Danish Ministry of Health and the Danish Environmental Protection Agency (MST-621-00013), and Kirsten and Freddy Johansen Foundation (grant no. 95-103-72087). The funding organizations played no role in the design and conduct of the study, in collection, management, analysis and interpretation of the data; or in the presentation, review or approval of the manuscript. The authors declare that they have no competing financial interests.

Perfluoroalkyl substances in human milk: a first survey in Italy.

Due to their widespread diffusion, perfluoroalkyl substances (PFASs) have been frequently found in the environment and in several animal species. It has been demonstrated that they can easily reach also humans, mainly through diet. Being lactation a major route of elimination of these contaminants, their occurrence in human milk is of particular interest, especially considering that it generally represents the unique food source for newborns. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the two most important compounds of this family, have been frequently found in human milk at variable concentrations, but still limited data are available. The present study, the first conducted in Italy capable to detect these pollutants at ultra-trace levels by UPLC-MS/MS, confirmed the role of lactation as a relevant source of exposure for breastfed children. The measured concentrations ranged between 15 and 288 ng/L for PFOS and between 24 and 241 ng/L for PFOA. Moreover, mean concentrations and frequencies of both analytes resulted higher in milk samples provided by primiparous women, suggesting that the risk of intake might be higher for first-borns. Finally, comparing these results with previous data, PFOS gradual decrease over time since year 2000 was confirmed.

Perfluoroalkyl acid (PFAA) levels and profiles in breast milk, maternal and cord serum of French women and their newborns

One major concern regarding perfluoroalkyl acids (PFAAs) is their potential role in onset of health troubles consecutive to early exposure during the perinatal period. In the present work, the internal exposure levels of 18 targeted PFAAs were determined in ca. 100 mother-newborn pairs recruited in France between 2010 and 2013. In serum, the cumulated concentrations of the 7 most frequently detected compounds were 5.70ng/mL and 2.83ng/mL (median values) in maternal and cord serum, respectively. Perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexylesulfonic acid (PFHxS) and perfluorononanoic acid (PFNA) contributed to around 90% of the total PFAAs contamination, with concentration levels and contamination profiles in accordance with other published work in Europe. Levels measured in breast milk were far lower (20 to 150 fold) than those determined in serum. Associations between the different monitored substances as well as between levels determined in the different investigated biological matrices mostly do not appear statistically significant. The estimated materno-foetal transfer would be thus substance-dependant, mainly driven by the physico-chemical properties of the different PFAAs (nature of polar group and length of alkylated side chain). We conclude that trans-placental passage and breastfeeding are both significant routes of human exposure to PFAAs.

Development of an analytical strategy based on liquid chromatography–high resolution mass spectrometry for measuring perfluorinated compounds in human breast milk: Application to the generation of preliminary data regarding perinatal exposure in France

Perfluorinated compounds (PFCs) are man-made chemicals for which endocrine disrupting properties and related possible side effects on human health have been reported, particularly in the case of an exposure during the early stages of development, (notably the perinatal period). Existing analytical methods dedicated to PFCs monitoring in food and/or human fluids are currently based on liquid chromatography coupled to tandem mass spectrometry, and were recently demonstrated to present some limitations in terms of sensitivity and/or specificity. An alternative strategy dedicated to the analysis of fourteen PFCs in human breast milk was proposed, based on an effective sample preparation followed by a liquid chromatography coupled to high resolution mass spectrometry measurement (LC-HRMS). This methodology confirmed the high interest for HRMS after negative ionization for such halogenated substances, and finally permitted to reach detection limits around the pg mL(-1) range with an outstanding signal specificity compared to LC-MS/MS. The proposed method was applied to a first set of 30 breast milk samples from French women. The main PFCs detected in all these samples were PFOS and PFOA with respective median values of 74 (range from 24 to 171) and 57 (range from 18 to 102) pg mL(-1), respectively. These exposure data appeared in the same range as other reported values for European countries.

Occurrence of perfluorinated alkylated substances in breast milk of French women and relation with socio-demographical and clinical parameters: results of the ELFE pilot study.

A previously developed and validated methodology based on liquid chromatography coupled to high resolution mass spectrometry was used for determine the concentration levels of 14 perfluoroalkylated substances (PFASs) in a set of 48 breast milk samples collected from French women in the frame of the ELFE pilot study. In accordance with other similar studies conducted at european and international levels, PFOS, PFOA, and PFHxS were detected and quantified in most of the analyzed samples (90%, 98% and 100%, respectively), and appeared as major contributors to the total PFAS exposure (38%, 37%, 25%, respectively), whereas the other targeted PFAS were very rarely, if not, found at the limits of detection of the method. Also in agreement with other published data, the concentration levels measured for the detected substances varied from <0.05 to 0.33μg/L for PFOS (median=0.079), from <0.05 to 0.22μg/L for PFOA (median=0.075), and from 0.04 to 0.07μg/L for PFHxS (median=0.050). On the basis of this relatively limited data set, no statistically significant relation was observed between these exposure levels and developmental outcomes, in particular the weight at birth. Similarly, no relation was observed between the measured PFAS levels and various socio-demographical parameters including the consumption of seafood, alcohol, smoking, or socio-economical level. These results suggest a need for further research and better knowledge regarding the sources, pharmacokinetics, and factors of exposure for other substances belonging to this class of emerging contaminants.

Comparative study of low- versus high-resolution liquid chromatography-mass spectrometric strategies for measuring perfluorinated contaminants in fish.

Perfluorinated compounds (PFCs) are usually monitored by high-performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) on triple quadrupole instruments. Although not yet widely implemented in the field, high-resolution mass spectrometry (HRMS) today appears as a valuable alternative for these halogenated chemicals due to their significant mass defect. Indeed, this second approach offers a way to cope with particular matrix effects caused by co-eluting and isobaric interferences affecting the measurement of some PFCs in fish. The present study compares three different LC-MS-related instruments and various signal acquisition modes, from low-resolution full-scan and selected ion-monitoring (SIM) mode on a triple quadrupole (QqQ) instrument to high-resolution full-scan or product ion-scan mode on orbital trap (LTQ-Orbitrap) or quadrupole-time-of-flight (Q-TOF) devices. Performances are compared for seven model compounds belonging to seven PFCs subclasses: perfluoralkylsulfonate, perfluoroalkylcarboxylate, perfluoroalkylsulfinate, perfluoroalkyl-sulfonamide, fluorotelomer saturated acid, fluorotelomer unsaturated acid and perfluoroalkylphosphonic acid. Low-resolution MS/MS was found to be unsurprisingly reliable for extended multi-residue monitoring. However, the high stability of PFCs leads to a relatively poor and non-specific fragmentation pathway in MS/MS. In addition, biliary acid-interfering compounds (e.g. taurochenodeoxycholic acid), which where encountered in the present case in fish samples but that may be present in other biological samples, were found particularly disturbing in low-resolution MS/MS. Indeed, these interferences presented the same retention time and diagnostic signals as PFOS, leading to a possible overestimation of the PFOS quantification in LC-MS/MS. On the other hand, high-resolution MS and MS/MS (LTQ-Orbitrap and Q-TOF) provided better results in terms of signal specificity and sensitivity. For instance, the estimated limits of detection (LOD) reached for PFOS on QqQ, Q-TOF and LTQ-Orbitrap instruments were 3.8, 0.7 and 0.5 pg injected, respectively.

Is the fresh water fish consumption a significant determinant of the internal exposure to perfluoroalkylated substances (PFAS)

PFAS are man-made compounds that are highly spread in the environment. Human dietary exposure to such contaminants is of high concern as they may accumulate in the food chain. Different studies already demonstrated the importance of the fish consumption in the dietary exposure of these molecules and the potential increase of internal doses of PFAS following the consumption of PFAS. However, so far few study aimed to study the link between the consumption of fresh water fishes and the internal exposure to PFAS. Objectives of this study were (i) to estimate the internal exposure of populations that are potentially high consumers of fresh water fishes and (ii) to determine whether the consumption of fish caught from fresh water is a significant determinant of the internal exposure of PFAS. In this work, a large sample of adult freshwater anglers from the French metropolitan population (478 individuals) was constituted randomly from participants lists of anglers associations. Questionnaires provided social and demographic information and diet information for each subject. In addition, analyses of blood serum samples provided the internal concentration of 14 PFAS. The survey design allowed to extrapolate the data obtained on the 478 individuals to the freshwater angler population. Descriptive data regarding internal levels of PFAS were discussed at the population level, whereas identification of the determinants were done at the 478 individuals level as sufficient contrast was required in terms of fresh water fish consumption. Only molecules for which the detection frequency were above 80% in blood were considered, i.e., PFOS, PFOA, PFHxS, PFNA, PFHpS, and PFDA. Distribution profiles showed log-normal distribution and PFOS and PFOA were the main contributors of the PFAS sum. For PFOS, the results obtained on the 478 individuals showed that upper percentiles were higher as compared to upper percentiles obtained on occidental general population. This confirmed an over-exposure of a fraction of the 478 individuals. Though, when the results were considered at the population level, the values were close. This was attributed to the low consumption frequency of fresh water fish in the general population. For PFOS, PFNA, PFHxS, PFHpS and PFDA, the fresh water fish consumption was identified as one of the contributors of internal PFAS concentrations. Gender, age, geographical location and consumption of home-grown products as other determinants were also discussed in this paper.

Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: high seafood consumers, high freshwater fish consumers and pregnant women.

Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC-MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination values<LOD considered as 0), high freshwater fish consumers appear as the most exposed to PFOS (7.5 ng.kg(-1) bw.d(-1)), PFUnA (1.3 ng.kg(-1) bw.d(-1)), PFDA (0.4 ng.kg(-1) bw.d(-1)) and PFHpS (0.03 ng.kg(-1) bw.d(-1)) while high seafood consumers appear as the most exposed to PFOA (1.2 ng.kg(-1) bw.d(-1)), PFNA (0.2 ng.kg(-1) bw.d(-1)) and PFHxS (0.06 ng.kg(-1) bw.d(-1)). For all considered populations, the major exposure contributors are fish, seafood and water under LB hypothesis, while dairy products, bread and crispbread are the main contributors under upper bound (UB) hypothesis. Besides this food exposure assessment, further studies are needed to assess the more global PFAA exposure, taking into account indoor and outdoor air, dust and cutaneous contact, which could be other important contributors for this particular class of chemicals.

Perfluoroalkyl acid contamination and polyunsaturated fatty acid composition of French freshwater and marine fishes.

In this study, French marine and freshwater fish perfluoroalkyl acid (PFAA) contamination are presented along with their fatty acid (FA) composition to provide further elements for a risk/benefit balance of fish consumption to be assessed. The 29 most consumed marine fish species were collected in four metropolitan French coastal areas in 2004 to constitute composite samples. Geographical differences in terms of consumed species and contamination level were taken into account. Three hundred and eighty-seven composite samples corresponding to 16 freshwater fish species collected between 2008 and 2010 in the six major French rivers or their tributaries were selected among the French national agency for water and aquatic environments freshwater fish sample library. The raw edible parts were analyzed for FA composition and PFAA contamination. Results show that freshwater fishes are more contaminated by PFAAs than marine fishes and do not share the same contamination profile. Freshwater fish contamination is mostly driven by perfluorooctane sulfonate (PFOS) (75%), whereas marine fish contamination is split between perfluorooctanoic acid (PFOA) (24%), PFOS (20%), perfluorohexanoic acid (PFHxA) (15%), perfluoropentanoic acid (PFHpA) (11%), and perfluorobutanoic acid (PFBA) (11%). Common carp, pike-perch, European perch, thicklip grey mullet, and common roach presented the most unfavorable balance profile due to their high level of PFAAs and low level of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs). These data could be used, if needed, in an updated opinion on fish consumption that takes into account PFAA contamination.

Tissue Uptake, Distribution, and Elimination of Perfluoroalkyl Substances in Juvenile Perch through Perfluorooctane Sulfonamidoethanol Based Phosphate Diester Dietary Exposure

Perfluorooctane sulfonamidoethanol based phosphate diester (SAmPAP) is a potential perfluorooctanesulfonate (PFOS) precursor. To examine whether SAmPAP exposure would result in fish contamination by perfluoroalkyl and polyfluoroalkyl substances (PFASs), juvenile Eurasian perch were dietarily exposed to this compound (dosed group) or exposed to the same tank water but fed control feed (control group). SAmPAP and metabolites were monitored in the muscle, liver, and serum during the 45-day exposure phase and 35-day depuration phase. SAmPAP was only detected in the dosed group and the absorption efficiency (0.04-2.25%) was very low, possibly related to its low bioavailability in the gastrointestinal tract, steric constraints in crossing biological membranes, and clearing by enterohepatic circulation. Although SAmPAP was biotransformed and eliminated at a slow rate (t1/2 > 18 days), its biomagnification factor was low. The observed metabolites in fish were N-ethyl perfluorooctane sulfonamidoacetic acid, perfluorooctane sulfonamidoacetic acid, perfluorooctane sulfonamide, and PFOS. Considering that SAmPAP was the only source of PFASs in the tanks, the occurrence of metabolites indicates that SAmPAP could be biotransformed in fish and contribute to PFOS bioaccumulation. However, levels of metabolites were not significantly different in the dosed and control groups, indicating that metabolite excretion followed by re-exposure to these metabolites from water was the main uptake route.