Cohort mortality studies have been the mainstay for evaluating cancer and other chronic disease risks in subjects resulting from exposures in the workplace. They have proven effective and reliable in detecting the carcinogenic effects of agents such as asbestos, benzene, aniline dyes, etc. in workers. They have also been the main sources of the epidemiologic evidence that these agents are carcinogenic in humans. They have led to regulatory actions that have resulted in the dramatic reduction of such harmful exposures in the workplace, hence succeeded in protecting workers' health. However, although a large number of these studies have been conducted in various occupational and industrial groups, much attention has not been paid in the United States to workers in the meat industry who are highly exposed to transmissible agents known to be potent causes of cancer, neurologic diseases such as 'mad cow' disease, and other severe infectious diseases in the animals they handle at work. Apart from the cohort assembled in this proposed study, to our knowledge this occupational group has not previously been evaluated for mortality in cohort studies in the US, even though similar studies in other countries have suggested these workers may be at increased risk of developing diseases such as cancer. We previously studied mortality (cancer and non-cancer) for the period 1949 to 1989 in an exposed cohort of 18,426 subjects who worked in abattoirs, meatpacking plants and supermarkets where exposure to these transmissible agents occurred from handling cattle, pigs and sheep or their products, and an unexposed control group of 6,078 subjects without such exposures. Exposed and unexposed subjects were identified from the rosters of a local meatcutters' union in Baltimore, Maryland. In this application we propose to update mortality in the cohorts through the end of 2005, by which time it is estimated 65% of the cohort would have died compared to 20% at the end of the previous follow-up. Also, while only 60 causes of death were evaluated in the previous follow-up, in this application a total of 185 individual causes of death will be investigated. This many causes of death to our knowledge has not been previously investigated in any occupational group. The study has the potential of linking important chronic diseases in humans with occupational exposure to transmissible agents in food animals, and will provide the basis for future planned studies. Infectious disease is a NIOSH priority area. ? ? ?
