The Branch studies the role of the environment in the etiology of certain chronic diseases. Environmental exposures may increase the risk of chronic disease, either directly, or through their interaction with individual characteristics such as hormonal status or genetic susceptibility. Data analysis continues in a multi-center case-control study of risk factors for chronic renal disease. Renal disease risk was increased for regular users of non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs), especially among older men and other high risk groups. Exposure to solvents and to silica was found to increase the risk of glomerulonephritis. Regular consumption of cola beverages was associated with an overall increase in risk. This was apparently not due to caffeine or artificial sweeteners, but to other unidentified constituents or factors associated with cola consumption. Although there was no independent risk from caffeine, heavy caffeine consumers appeared to be at increased risk of nephrotoxicity from NSAIDs. Consumption of alcoholic beverages was associated with a slight increase in risk, but no risk was conferred by smoking. To better understand the influence of hormone status on disease risk, a cohort of 1000 women who have contributed prospective menstrual and reproductive data since 1935 are being followed to determine their risk of several diseases. To date, almost 90% of the cohort has been traced, with approximately 700 found to be alive, and 200 known to be deceased. Questionnaires were sent and death certificates and medical records will be retrieved. Previous work in the Branch has shown that x-ray evidence of asbestos exposure identifies non-occupationally exposed persons, and can predict lung cancer risk.
