A case-control study of stomach cancer in a coal mining region of Pennsylvania.

Historically coal mining populations have been reported to have elevated stomach cancer incidence rates. To identify which factors might be associated with cases who reside in these high risk areas, and specifically if particulate exposures from coal mining and coal utilization are associated with risk, a mining area of western Pennsylvania was defined for a retrospective case-control study. One hundred seventy-eight resident cases, identified from certificates of death, were compared to three controls: digestive cancer deaths, arteriosclerotic heart disease deaths, and neighborhood (living) controls. Controls were matched to each case on age, race, sex, and residence. Interviews were conducted during 1981 and 1982. Excess risks were shown for foreign born and eastern Europeans. Coal mining was not shown to be a risk factor for males, while an association was seen for female cases whose husbands were miners. Farming was a risk factor for males and females. Marked decreased risks were shown for gas heating and cooking fuels, with elevated risks for coal, wood and oil heating fuels, and wood cooking fuel. These findings are associated with lower socioeconomic status, and suggest environmental exposures or lifestyles that are directly and indirectly related to these risks factors. The marked inverse relationship between stomach cancer and use of gas heating and cooking fuel may be of important etiologic significance, especially in association with dietary changes. Further evaluation of prior use of various types of heating and cooking fuels needs to be considered especially using incident rather than case deaths.