Pesticide exposures and other agricultural risk factors for leukemia among men in Iowa and Minnesota.

Mortality surveys and death certificate studies have suggested an association between leukemia and farming. To investigate whether exposure to carcinogens in an agricultural setting is related to risk of leukemia, the authors conducted a population-based case-control interview study of 578 white men with leukemia and 1245 controls living in Iowa and Minnesota. Consistent with recent mortality studies, there were slight, but significant, elevations in risk for all leukemia [odds ratio (OR) 1.2] and chronic lymphocytic leukemia (OR 1.4) for farmers compared to nonfarmers. There were no significant associations with leukemia for exposure to specific fungicides, herbicides (including 2,4-D and 2,4,5-T), or crop insecticides. However, significantly elevated risks for leukemia of greater than or equal to 2.0 were seen for exposure to specific animal insecticides including the organophosphates crotoxyphos (OR 11.1), dichlorvos (OR 2.0), and famphur (OR 2.2) and the natural product pyrethrins (OR 3.7) and the chlorinated hydrocarbon methoxychlor (OR 2.2). There were also smaller, but significant, risks associated with exposure to nicotine (OR 1.6) and DDT (OR 1.3). This finding of elevated risks for insecticides used on animals deserves further evaluation.

Leukemia and farm practices in Iowa.

Death certificate analyses of 1675 white, male Iowans over age 30 years who died of leukemia in 1964-1978 were completed. Each case was matched to two controls on age (within two years) at death, county of usual residence and year of death. Consideration of usual occupation, as recorded on the death certificate, resulted in an odds ratio for leukemia mortality among farmers of 1.24 (p less than 0.05). The highest odds ratios for farmers were observed in those born after 1890, those dying after 1970, and those dying at age 65 years or younger. Odds ratios for farmers were also elevated in counties with high soybean and corn production per acre for those born between 1890 and 1900. For those born after 1900, odds ratios for farmers were increased in counties with the greatest numbers of egg-laying chickens and largest number of acres treated with herbicides. The types of leukemia causing elevated mortalities in Iowa farmers were chronic lymphatic and unspecified lymphatic. Mortality from unspecified lymphatic leukemia was associated with corn per acre, number of milk cows and number of egg-laying chickens.

Selected cancer mortality and farm practices in Iowa.

Death certificate analyses of white male Iowans over age 30 who died of multiple myeloma, non-Hodgkin's lymphoma, prostate cancer or stomach cancer between 1964 and 1978 were completed. Each case was matched to two controls on age (within two years) at death, county of residence, and year of death. Consideration of usual occupation, as recorded on the death certificate, resulted in the following odds ratios for mortality due to the specified cancers among farmers: multiple myeloma, 1.48; non-Hodgkin's lymphoma, 1.26; prostate cancer, 1.19; and stomach cancer, 1.32. Each is statistically significant (p less than 0.05). Odds ratios were computed separately for three birth cohorts according to counties stratified by crop and livestock production. Multiple myeloma was elevated in those born after 1890 and was associated with number of egg-laying chickens, hog production, insecticide use, and herbicide use. Non-Hodgkin's lymphoma was elevated in those born before 1901 and was associated with egg-laying chickens, milk products sold, hog production, and herbicide use. Although prostate cancer was elevated in those born before 1901, it was not associated with any agricultural practice. Stomach cancer was elevated in each birth cohort. It was associated with milk products sold, cattle production, and corn per acre.

Data management of a case-control study with a large number of variables.

The description is presented of the system design and implementation experience obtained while providing the data management for a case-control study involving a large number of variables. Topics concerning questionnaire design, data collection, data coding, data entry, data edit, and data storage and retrieval are discussed. Designing and implementing the data-processing system for such a study provides diversified data management experience. This experience results in the investigation of existing and the development of new procedures and documents that can be applied to other studies in medical research. Emphasis is placed on the presentation of system details that can be tailored to specifications for a variety of studies.

1983 occupational injury hospital admissions in Iowa: a comparison of the agricultural and non-agricultural sectors.

An occupational injury surveillance project was conducted in 15 of Iowa's 99 counties. Trained abstractors reviewed the medical records of persons admitted for trauma to hospitals during 1983. Based on these chart reviews, subsequent mail-out questionnaires and phone contacts were made, and rate estimates for occupational injury hospitalization for farmers and non-farmers were generated. The 1980 U.S. census data for occupation and market area data for the sample hospitals were used for the rate calculations. Approximately 14.7% of hospitalizations for trauma in the sample area were for work-related injuries. Farmers were hospitalized for occupational injuries at a rate of 1,521/100,000 compared to non-farmers at a rate of 497/100,000. There were no significant differences in the mean number of days per hospitalization for farmers versus non-farmers, (7.4 days for farmers and 6.7 days for non-farmers). Based on the questionnaire data, farmers were much less likely to receive any form of remuneration for injury, (odds ratio = 0.26, p less than 5 x 10(-6]. Farmers also reported less time off from work, with a mean of 79 days compared to non-farmers with a mean of 289 days.

Occupational disease surveillance data sources, 1985.

Health department epidemiologists in 50 states, New York City, and the District of Columbia were surveyed in 1985 about seven potential data sources for occupational disease surveillance. Reported sources of occupational disease data were: automated workers' compensation claims (63 per cent of the 52 respondents); provider reports (62 per cent); death certificates with occupation or industry (60 per cent); cancer registries with occupational histories (35 per cent); birth certificates with parent's occupation (27 per cent); non-cancer disease registries (13 per cent); and hospital or insurance records (8 per cent).