Per- and polyfluoroalkyl substances (PFAS) and neurobehavioral function and cognition in adolescents (2010–2011) and elderly people (2014): results from the Flanders Environment and Health Studies (FLEHS)

Abstract

Background PFAS are persistent, bioaccumulative compounds repelling water, oil and stains which are widely used. There is mounting evidence linking exposure to a range of adverse health outcomes including renal, hepatic, immunotoxic, reproductive, endocrine disrupting and carcinogenic effects. PFAS possibly also induce neurobehavioral and developmental effects. Within Flanders Environment and Health Studies (FLEHS) internal exposure to PFAS and relevant health effects are assessed since 2008. Results Adolescents 14–15 y (2010–2011) living in an industrially contaminated area (without known PFAS contamination) and adults 50–65 y (2014) randomly sampled from the general Flemish population using a stratified clustered multi-stage design, were recruited. For the adolescents perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were measured in serum, for the adults PFOS, PFOA, perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA) and perfluorobutane sulfonate (PFBS). In adolescents the Neurobehavioral Evaluation System (NES3) computerized battery of tests developed to study the neurological effects of an exposure to environmental agents was applied. The adults did the Stroop test, the NES3 Continuous Performance Test and the NES3 Digit Span Test. In adolescents sleepiness, masculinity and femininity were assessed via the Epworth Sleepiness Scale and Personal Attributes Questionnaires, respectively. In adolescents PFOA was associated with significantly increased somnolence, and PFOS with a significant inverse association with boys’ femininity and with girls’ masculinity. In adolescents, PFAS were also associated with a marginal decrease in sustained attention (PFOS) and cognitive performance (PFOA) and a significant decrease in short-term memory (PFOS). However, in older adults PFOS was associated with a significant increase in the capacity to pay attention and PFHxS with a significant increase in sustained attention. Conclusion Our observations point to neurobehavioral and cognitive effects of PFAS. The neurobehavioral effects might in part result from the changes in sex hormone levels that have been reported to be associated with internal exposure to PFAS. Interestingly, whereas in relation to cognition some adverse effects were recorded for adolescents, for elderly persons our observations rather suggest possible weak positive effects with respect to cognition. Our observations might be in line with the view that PFAS have many, sometimes contrasting health effects.

Per- and polyfluoroalkyl substances (PFAS) and immune system-related diseases: results from the Flemish Environment and Health Study (FLEHS) 2008–2014

“…Regression analyses are sensitive to influential cases, whose deletion from the dataset would noticeably change the result of the calculation. Exclusion of influential cases was performed as described and discussed in detail by van Larebeke et al [30]. We present results after exclusion of influential cases.…”

“…The statistical analysis was performed as described in detail by van Larebeke et al [30] Associations with biological or health effects were only assessed for PFASs for which measurable quantities were observed for the vast majority of participating subjects. Therefore, it was deemed acceptable to replace values below the LOQ by LOQ/2.…”

“…1). Their selection and recruitment were described in more detail by van Larebeke et al [30]. The industrial contaminated site had no specific records of PFAS production.…”

“…As described in detail by van Larebeke et al [30] participants, and in the case of adolescents also their parents, completed a self-reporting questionnaire on socioeconomic status and personal and lifestyle factors, including: age, country of birth of their parents, weight, height, housing, residence history, occurrence of in-house structural modifications or painting, family composition, density of nearby traffic, in-house use of pesticides and in-house exposures to pollutants and chemicals (in terms of use or exposure to solvents, insecticides, herbicides, passive smoking, air refreshers, sprays for impermeabilizing clothes, personal care products, disinfectants) sports, hobbies, contact with animals, smoking and consumption of alcohol, health status and disease experience, occurrence of asthma or eczema or allergies among relatives. For mothers and other women, info was recorded on menstrual cycle and parity.…”

“…Measurement of PFOS, PFHxS, PFOA, PFNA and PFBS in peripheral serum and cord plasma was described in detail by van Larebeke et al [30]. Briefly, using procedures as described by Kato et al [38], the analytical method consisted of an offline protein precipitation with acetonitrile, followed by separation by HPLC and MS/MS detection (Applied Biosystems API3000 triple quadrupole mass spectrometer (Foster City, CA, USA) in negative ionization MS/MS mode with multiple reaction monitoring.…”