The impact of environmental exposure to pesticides from agricultural drift on human health is a major public health concern. The International Agency for Research on Cancer (IARC) has classified several pesticides as carcinogenic or probable carcinogenic to humans. Residential proximity to treated farmland is a source of environmental pesticide exposure and has been associated with increased concentrations of pesticides in residential dust and urine samples. Little is known on the seasonal variations of pesticide concentrations. The SIGEXPOSOME project aims to investigate seasonal variations of the exposure to multiple agricultural pesticides of residents proximate to vineyards and of pesticide applicators in the Beaujolais area of the Auvergne-Rhône-Alpes Region, France. The study is based on a longitudinal study involving overall 185 subjects, with repeated sampling of multiple matrices (residential dust, urine, blood and hair). We report here preliminary results on 19 residents.

We sampled morning urine and household dust in 19 non-smoking, men, aged 18 to 65 years, without professional pesticides use, residing in the study area. Sampling was performed in July and October 2015. House dust: We used the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method for extraction and analytical multi-residue methods based on gas chromatography coupled to mass spectrometry (GC–MS) and liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). After analyses of the efficiency and repeatability of the analytical methods for 62 compounds, 53 pesticides were retained for analyses [recovery rate 70–120%; relative standard error (RSD)<20%; LOQ 20ng/g to 1000ng/g dust]. Urine samples: In order to screen presence of pesticides and their metabolites in urine samples, a database containing 59 pesticides and their 519 associated metabolites with their exact monoisotopic mass was set up. After solid phase extraction, the concentrated extracts of urine samples were analyzed in full scan mode by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS).

House dust: 40 pesticides out of 53 were quantified, including 11 compounds of high public health priority. Among pesticides with a detection frequency>70% for at least one of the two sampling periods, we observed significant seasonal variations in prevalence for 10 pesticides (out of 18) and significant differences in concentrations for 14 pesticides: Chlorpyriphos, Cyprodinil, Difenoconazole, DimetomorpheI, DimetomorpheII, Fludioxynil, Indoxacarbe, Kresoxim-methyl, Myclobutanil, SpiroxamineI, SpiroxamineII, Tebuconazole, Trifloxystrobin and Zoxamide with an average concentration higher in July than in October. Urine samples: The LC-HRMS analyses showed the presence of three pesticides metabolites: 3,5,6-trichloro-2-pyridinol (TCPy), a specific metabolite of the organophosphate insecticides chlorpyrifos and chlorpyrifos-methyl; 3-phenoxybenzoic acid (3-PBA), a nonspecific metabolite of the pyrethroid insecticides permethrin, cypermethrin or cyhalothrin; hydroxy- and carboxy-metabolites of tebuconazole. The identity of TCPy and 3-BPA was confirmed by comparison with authentic standards.

This study, analyzing the seasonal variations of multiple pesticides, is unique in France. House dust of non-professional residents proximate to vineyards showed seasonal variations with higher prevalence and concentrations of agricultural pesticides during the application period. Also, results show the capacity of our screening approach based on LC-HRMS to detect agricultural compounds present at low concentrations in urine. Correlation between residential dust and urine contamination will be further explored as well as association between concentrations of pesticides in house dust and urine, and proximity to treated vineyards, a surrogate for pesticides drift.

Auvergne-Rhône-Alpes Region; Métropole Lyon; Cancéropole CLARA.