Association between residential proximity to agricultural crops and adaptive behaviors in children with autism spectrum disorder from the French ELENA cohort.

Influences of pesticide exposures on the clinical expression of children with ASD not known. The aim of this study was to analyze the associations between early residential proximity to agricultural crops, proxy of exposure to pesticides, and adaptive behaviors in children with ASD. Children with ASD were recruited within the Etude Longitudinale de l'Enfant avec Autisme (ELENA) French cohort. Adaptive behaviors were assessed with the second edition of the Vineland Adaptive Behavior Scales (VABS-II). Baseline subscores in communication, daily living skills and socialization were considered. Residential exposure to agricultural crops was estimated by crops acreage within a 1000m radius around homes. We ran multiple linear regression models to investigate the associations between exposures to agricultural crops during the pregnancy (n = 183), the first two years of life (n = 193) and adaptive behaviors in children with ASD. The mean (SD) age of children at the inclusion in the ELENA cohort was 6.1 (3.5) years, 39% of them presented an intellectual disability (ID). The mean communication score was 73.0 (15.8). On average, the crop acreage covered 29(27)% of the acreage formed by the 1000m radius around homes. Each increase of 20% in the crop acreage was associated with a significant decrease in communication score of the VABS-II in children without ID for the pregnancy (ß = -2.21, 95%CI: 4.16 to -0.27) and the first two years of life (ß = -1.90, 95%CI: 3.68 to -0.11) periods. No association was found in children with ID. This study opens perspectives for future works to better understand ASD phenotypes.

Pesticides used in Europe and autism spectrum disorder risk: can novel exposure hypotheses be formulated beyond organophosphates, organochlorines, pyrethroids and carbamates? - A systematic review.

BACKGROUND: A growing body of evidences suggests an association between early exposure to organophosphates (OPs), organochlorines (OCs), pyrethroids or carbamates and autism spectrum disorder (ASD). However, there are limited data about the other pesticide groups, especially in Europe. OBJECTIVES: Based on a systematic review, we aimed to assess the influence of neuro- and thyrotoxic agricultural and domestic pesticides (other than OPs, OCs, pyrethroids and carbamates) authorized in Europe on risk of ASD in children or ASD behavioral phenotypes in rodents. METHODS: Pesticides were initially identified in the Hazardous Substances Data Bank. 20 currently used (10 pesticide groups) were retained based on the higher exposure potential. Epidemiological (children) and in vivo (rodents) studies were identified through PubMed, Web of Science and TOXLINE, without restriction of publication date or country (last update: November 2019). The risk of bias and level of evidence were also assessed. This systematic review is registered at the International Prospective Register of Systematic Reviews (PROSPERO, registration number CRD42019145384). RESULTS: In total, two epidemiological and 15 in vivo studies were retained, focusing on the azole, neonicotinoid, phenylpyrazole and phosphonoglycine pesticide groups. No study was conducted in Europe. Glyphosate, imidacloprid, clothianidin, myclobutanil, acetamiprid, tebuconazole, thiabendazole and fipronil, globally reported an association with an increased risk of ASD in children and/or ASD behavioral phenotypes in rodents. In children, glyphosate and myclobutanil showed a "moderate level of evidence" in their association with ASD, whereas imidacloprid showed an "inadequate level of evidence". In rodents, clothianidin, imidacloprid and glyphosate showed a "high level of evidence" in their association with altered behavioral, learning and memory skills. CONCLUSION: In the framework of environmental risk factors of ASD, novel hypotheses can be formulated about early exposure to eight pesticides. Glyphosate presented the most salient level of evidence. Given their neuro- and thyrotoxic properties, additional studies are needed for the 12 other pesticides not yet studied as potential ASD risk factors according to our inclusion criteria.

Dietary exposure to brominated flame retardants and risk of type 2 diabetes in the French E3N cohort.

INTRODUCTION: The prevalence of type 2 diabetes (T2D) is increasing worldwide. Recent studies have suggested that environmental factors, such as exposure to brominated flame retardants (BFRs), could play a role in the epidemic of T2D. The aim of this study was to analyze the association between the dietary exposure to BFRs (Hexabromocyclododecane (HBCD) and Polybromodiphenylether (PBDE)) and T2D risk in the E3N prospective cohort of French women. RESEARCH DESIGN AND METHODS: Overall, 71,415 women followed for 19 years were included in the study. We performed Cox regression models to analyze the association between dietary exposure to BFRs and T2D risk. RESULTS: Overall 71,415 women were included and 3667 (5.13%) developed a T2D during follow-up. The mean dietary exposure to HBCD and to PBDE was 0.22 ng/kg body weight (BW)/day and 1.21 ng/kg bw/day, respectively. There was a positive linear association between dietary exposure to HBCD and T2D risk starting from the 2nd quintile group (HR: 1.18; 95% CI: 1.06-1.30) to the 5th quintile group (HR: 1.47; 95% CI: 1.29-1.67) when compared to the 1st quintile group. We also found positive although non-linear associations between dietary exposure to PBDE and T2D risk, with an increased HR only for the 2nd and 4th vs. 1st quintile groups (HR: 1.12; 95% CI: 1.02-1.24, and HR: 1.20; 95% CI: 1.08-1.34, respectively). CONCLUSION: The findings suggest an association between dietary exposure to BFRs and T2D risk, highlighting the importance of further investigating this association the long-term health effects of endocrine disruptors in the general population. Additional studies are needed to reproduce these findings in other populations and clarify the underlying biological mechanisms.