Estimation of daily intake and risk assessment of organophosphorus pesticides based on biomonitoring data - The internal exposure approach

Human exposure to pesticides can be estimated through different approaches. The approach adopted in this study is based on internal dose measures. Studies published during 2001 and 2017 were collected from PubMed and Scopus databases, filtered and organized. The intake of parent compounds is estimated based on the urinary excretion of different OP metabolites applying a mathematical model previously used for similar purposes. Once defined an Estimated Daily Intake (EDI), risk assessment is performed through comparison with specific guideline values and hazard index (HI) is calculated to assess cumulative health risk. The EDI was expressed as malathion, diazinon, parathion, phorate and dimethoate equivalents. Differences in exposure between pregnant women, general population, children and farmers are highlighted and exposures are presented by country and sampling year. Higher exposure to OPs was calculated for farmers, followed by children whereas pregnant women were less exposed. Median HQ values for children ranged between 0.016 and 0.618, for pregnant women 0.005-0.151, for general population 0.008-0.206 and for farmers 0.009-0.979. Combined exposure to dimethoate and phorate was the worst-case scenario. The annual distribution of the urinary DAPs showed that exposure to OPs since 1998 tends to be stable for both children and adults.