Mortality from cancer and other diseases in poultry slaughtering/processing plants.
BACKGROUND: Healthy chickens or turkeys and their eggs destined for human consumption are commonly infected with viruses which cause cancer in these animals. Some of the viruses can infect and transform human cells in vitro, and human sera show serological evidence of infection with these viruses. It is not known whether the viruses cause cancer in humans. METHODS: We conducted a mortality study of a subcohort of 2639 workers in poultry slaughtering plants who have one of the highest human exposures to these viruses, and 6081 unexposed workers from non-meat companies (controls). All were members of a local meatcutters' union in Baltimore. RESULTS: Statistically significant increased risks were observed for cancer of the oesophagus, liver cancer, tumours of the haemopoietic lymphatic system, and motor vehicle accidents, in the group of poultry workers as a whole or in particular race/sex subgroups. The results for other causes of death showed consistently elevated risks in most race/sex subgroups, but these were not statistically significant. CONCLUSION: The cohort is young, and because the number of deaths is small, the results though suggestive of increased risks for some causes, are inconclusive. However they indicate that this cohort is of interest, and that further follow-up might reveal a much clearer and consistent picture.