Urinary levels of pyrethroid pesticides and determinants in pregnant French women from the Elfe cohort

Pyrethroids are insecticides which are widely used for agricultural and domestic purposes. The general population can be exposed to them. Given the suspected effects of pesticides on the development of the foetus, exposure to pyrethroids during pregnancy is a major public health concern. The objective of this paper is to describe the urinary levels of the following five pyrethroid metabolites and their associated determinants among pregnant French women in 2011 enrolled in the Elfe cohort (n = 1077): a) 3-phenoxy benzoic (3-PBA), b) 4‑fluoro‑3‑phenoxy benzoic acid (4-F-3-PBA), c) Cis‑3‑(2,2dibromovinyl)‑2,2‑dimethyl cyclopropane-carboxylic acid (Cis-DBCA); d) Cis‑3‑(2,2dichlorovinyl)‑2,2‑dimethyl cyclopropane-carboxylic acid (Cis-DCCA) and e) Trans-3‑(2,2dichlorovinyl)‑2,2‑dimethyl cyclopropane-carboxylic acid (Trans-DCCA). The distribution levels were estimated for each pyrethroid metabolite. Multivariable analyses helped determine the predictors of these levels. All metabolites except 4-F-3-PBA were detected in all the urine samples. The mean urinary concentration of the sum of the metabolites (3-PBA, Cis-DBCA, Cis-DCCA, Trans-DCCA) was 1.18 μg/L, with the highest concentrations observed for 3-PBA. A comparison of these levels with other studies showed that pregnant French women tend to be more exposed to pyrethroids than their American counterparts, less exposed than Chinese and Caribbean mothers, and have similar exposure to Japanese mothers. In our study, urinary levels of pyrethroid metabolites were positively related to smoking during pregnancy, consuming fish and alcohol, domestic pesticide use and living in the vicinity of crops during pregnancy. These findings highlight the importance of non-dietary pathways when evaluating exposure to pyrethroids.