Altered thyroid hormones and cytogenetic profiles in backpack sprayers using ethylene bisdithiocarbamate (EDBC) fungicides in Mexico.
Steenland-K; Cedillo-L; Tucker-J; Hines-C; Sorensen-K; Deddens-J; Cruz-V
Am J Epidemiol 1997 Jun; 145(11)(Suppl):S40
EBDC (ethylenebisdithiocarbarnate) fungicides are used heavily in the U.S. EBDCs are metabolized to ethylene thiourea (ETU). The US EPA classifies ETU as a carcinogen based on animal data, and has restricted their use. There are no data on the potential carcinogenicity of EBDCs in humans, and only one study on human genotoxicity. ETU causes alters thyroid hormones in rodents, decreasing T4 and increasing TSH. The authors have studied cytogenetic outcomes and thyroid hormone levels among 49 heavily exposed workers spraying EBDC on tomatoes in Mexico, along with 14 lightly exposed land owners and 31 nonexposed controls. Urinary ETU was used to compare exposure between groups. The authors found an increase in TSH (p=02) among applicators compared to controls, but no decrease in T4. The authors found increases in sister chromatid exchange (p=02) and in all chromosomal translocations (p=05) for applicators compared to controls; however, the subset of reciprocal translocations showed a lesser increase (p=.4). Translocations are chromosomal aberrations which persist through cell division; they are elevated in tumors, often occurring at sites of genes affecting cell cycle and tumor suppression. These data suggest that EBDCs are affecting the thyroid and the lymphocyte genome among heavily exposed workers.
Fungicides; Cancer-rates; Carcinogens; Thyroid-gland-disorders; Hormone-activity; Exposure-assessment; Genotoxic-effects; Cell-damage; Lymphocytes; Agricultural-chemicals; Agricultural-workers; Sprays
American Journal of Epidemiology