Abstract 610: A longitudinal investigation of hematologic perturbations among permethrin-exposed pesticide applicators in the Biomarkers of Exposure and Effect in Agriculture Study

Abstract

Abstract Background: In the Agricultural Health Study, a large prospective cohort of pesticide applicators, high lifetime use of the insecticide permethrin was associated with an increased risk of multiple myeloma. However, the biological mechanisms through which this association occurs remain to be fully understood. Methods: Hematologic perturbations were assessed among 33 permethrin-exposed male pesticide applicators enrolled in the Biomarkers of Exposure and Effect in Agriculture study, a molecular substudy within the Agricultural Health Study. Serial blood samples were collected from each participant coinciding with permethrin use including visits during the offseason, an exposure visit the day after use, and for 27 participants a follow-up visit approximately three weeks after use. Complete blood count with white blood cell differential and lymphocyte subsets were collected at each visit. Linear mixed models were used to assess the relationship between permethrin exposure and hematologic parameters, controlling for potential confounders including season of blood draw, age, body mass index, recent cold/infection, and use of other pesticides. Results: A statistically significant increase in the adjusted mean immature granulocyte count (37%, 95% CI=6%, 76%) was observed the day after permethrin use compared to an offseason visit. Statistically significant (P<0.05) alterations in several red blood cell (RBC) parameters were also observed on the day after permethrin use, including decreased RBC count and hemoglobin and increased mean corpuscular volume and RBC distribution width-SD. Decreases in RBC count and hemoglobin, and increased levels of RBC distribution width-SD persisted approximately three weeks after permethrin use. Conclusions: Altered hematologic parameters could be indicative of disrupted hematopoiesis, providing insights into the potential biologic plausibility of the observed association between permethrin use and multiple myeloma risk among pesticide applicators. Impact/Significance: Given the widespread use of permethrin in both residential and commercial settings, our findings may have public health implications beyond occupationally exposed pesticide applicators. Citation Format: Joe Shearer, Laura Beane Freeman, Danping Liu, Gabriella Andreotti, Jennifer Hamilton, Julie Happel, Charles Lynch, Michael Alavanja, Jonathan Hofmann. A longitudinal investigation of hematologic perturbations among permethrin-exposed pesticide applicators in the Biomarkers of Exposure and Effect in Agriculture Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 610.