Exposure to pyrethroid and organophosphate insecticides in children – risk assessment for adverse effects on neuropsychological development and hormonal status (PyrOPECh)

Croatian Science Foundation research project
Participants: Jelena Kovačić, Adrijana Bjelajac, Jasminka Bobić (do 2022), Selma Cvijetić Avdagić, Jelena Macan, Rajka Turk, Martina Piasek (do 2020), Željka Babić, Jim Garvey, Marija Posavec, Vera Musil, Bernarda Krnić, Marijana Matek Sarić, Irena Keser, Saša Kralik Oguić, Iva Bebek, Gordana Jurak, Tatjana Petričević-Vidović, Anne Nugent, Matijana Jergović, Romana Gjergja Juraški, Snježana Sekušak-Galešev, Breige McNulty, Katja Dumić Kubat, Brendan Murray, Andreja Jurič, Marija Macan, Antonija Sulimanec Grgec, Patricia Tomac, Eva Anđela Delale
Head: Veda Marija Varnai
Epidemiological studies and animal experiments indicate the potential adverse effects of exposure to pyrethroid (PYR) and organophosphate (OP) insecticides on brain and sexual development in children, even at very low exposure levels. However, limited number of studies explored these potential risks during puberty, with inconsistent results and significant methodological limitations, such as insufficiently assessed exposure and cross-sectional study design. The main objective of the proposed research is to assess the risk of PYR and OP insecticide exposure to neuropsychological development and hormonal status in prepubertal and pubertal boys in a 2-year cohort study, while controlling for potential confounders, and using only non-invasive methods. Children’s exposure to PYR and OP insecticides will be assessed by biomonitoring (analysing urinary pesticide metabolites) in the 5th and 7th grades of elementary school, and by dietary exposure assessment – 24-hour dietary recall on five occasions during 2-year follow-up. In the 5th and 7th grades, neuropsychological development will be evaluated by testing attention, memory and simple psychomotor response speed, and by assessing the characteristics of child’s sleep and behaviour. Pubertal development will be evaluated by clinical examination (according to Tanner and Prader), and urinary gonadotropins and salivary sex hormones (testosterone and dehydroepiandrosterone sulfate) measurements. The research is expected to 1) increase the knowledge on possible risks of PYR and OP insecticides’ exposure for neurodevelopment and hormonal status in pubertal boys; 2) help to recognise deficiencies and assess available methodology for evaluation of developmental neurotoxicity and endocrine disruption within the framework of regulatory toxicology; 3) improve insufficient methodology for exposure assessment of non-bioaccumulative pesticides; 4) contribute to the better characterisation of pesticide exposure in the Croatian population.