Studies and Reports
- Purdue M et al., Occupational exposure to organochlorine insecticides and cancer incidence in the Agricultural Health Study, Int J Cancer. 2007 Feb 1;120(3):642-9.
- Abstract. "Organochlorine (OC) insecticides have been regulated as possible human carcinogens primarily on the basis of animal studies. However, the epidemiologic evidence is inconsistent. We investigated the relationship between cancer incidence and OC insecticide use among pesticide applicators enrolled in the Agricultural Health Study, a prospective cohort study of 57,311 licensed applicators in Iowa and North Carolina enrolled between 1993 and 1997. Information on ever use of 7 OC insecticides (aldrin, chlordane, DDT, dieldrin, heptachlor, lindane, toxaphene) was collected from a self-administered questionnaire at enrollment. Lifetime exposure-days to OC insecticides were calculated using additional data from a take-home questionnaire completed by 25,291 participants (44% of total). We found no clear evidence of an association between use of OC insecticides and incident cancers (N = 1,150) ascertained through December, 2002. When we focused on individual insecticides and structurally similar groups (aldrin and dieldrin; chlordane and heptachlor), significantly increased relative risks of some cancers were observed for use of some chemicals (rectal cancer and chlordane, lung cancer and dieldrin, non-Hodgkin lymphoma (NHL) and lindane, melanoma and toxaphene, leukemia and chlordane/heptachlor). Some significant decreased relative risks were also observed (colon cancer and aldrin; overall cancer and heptachlor). In conclusion, we did not observe any clear relationship between cancer risk and the use of OC insecticides. Our chemical-specific findings are based on small numbers and multiple comparisons, and should be interpreted with caution; however, some observed associations (lindane and NHL, chlordane/heptachlor and leukemia) are supported by previous evidence."
- Ditraglia D et al., Mortality study of workers employed at organochlorine pesticide manufacturing plants, Scand J Work Environ Health. 1981;7 Suppl 4:140-6.
- Abstract. "A retrospective cohort study was conducted to examine the mortality of workers employed in the manufacture of the chlorinated hydrocarbon pesticides, chlordane, heptachlor, dichloro-diphenyl-trichloro-ethane (DDT) and aldrin/dieldrin/endrin. Four manufacturing plants were selected for study, and each cohort included all workers employed for at least six months prior to January 1964. The entire study group totaled approximately 2,100 individuals. Vital status ascertainment for these cohorts ranged from 90 to 97% complete; the cut-off date for follow-up was 31 December 1976. In general there were too few deaths in this study on which to draw any meaningful conclusions. The standardized mortality ratio (SMR) for all causes in each cohort was below the expected level (100) and ranged from 66 to 82, probably a reflection of the "healthy worker effect." For "all malignant neoplasms" the SMRs ranged from 68 to 91 and for respiratory cancer from 55 to 132. In the aldrin/dieldrin/endrin cohort observed deaths due to pneumonia and "other respiratory diseases" were significantly above the expected number of deaths. For several other specific cancer sites (stomach in plant 1, esophagus, rectum, liver and lymphatic/hematopoietic system in plant 3), the observed deaths were more than the expected number and should be examined in more detail. It is recommended that these cohorts be followed for several more years and the mortality patterns be reexamined."