O-123 DNA damage in lymphocytes of female farmers measured using the alkaline comet assay.

Introduction Many studies have shown a link between exposure to pesticides and a higher level of DNA damage. However, longitudinal studies are rare and little is known about long term DNA damage and cancer risk in exposed subjects. Objectives i) Quantify DNA damage for the women included in a French agricultural cohort at two time points, ii) study the relationship between DNA damage and agricultural tasks, and iii) between DNA damage and cancer incidence. Methods 320 female agricultural workers were enrolled from 1997 to 2000 and completed a face-to-face questionnaire. 245 gave a blood sample at enrolment (T0). Ten years later, 104 donated another sample (T10). Using the comet assay with an internal historical negative control, we quantified DNA damage in PBMC on 200 nuclei using a 4-category visual scoring system. Results At enrolment, there were no differences in DNA damage for farm owners/co-owners (n=135, 55%, p=0.84), or participants in livestock tasks within our study population (n=159, 65%, p=0.23). Pesticide exposure through application of anti-parasites to livestock (n=138, 56%, p=0.25) and disinfection of milking equipment (n=117, 48%, p=0.78) did not influence DNA damage. However, damage tended to be higher for those implicated in milking (n=109, 44%, p=0.18). Women who carried out administrative (n=180, 73%) and domestic tasks (n=213, 87%) tended to have lower damage scores (p=0.08 and p=0.07, respectively), as well as women who undertook other tasks had significantly lower damage (p=0.04) than those not involved. From enrolment to end of 2017, 37 incident cancer cases were diagnosed, of which 21 were breast cancer cases. No association was found between DNA damage and cancer incidence (p=0.45). Conclusion Occupational exposure in the agricultural field could be evaluated using the comet assay. Women’s involvement to tasks not related to farm upkeep show a lower level of DNA damage than those not undertaking these tasks.