The objectives of this project are to identify and describe environmental and host determinants of cancer in areas at high risk of cancer through the use of analytical epidemiologic and biometric techniques, particularly case-control studies of specific cancers. Completed during the year were case-control studies of respiratory cancer in New Jersey and coastal Texas; lung, stomach, and pancreas cancers in Louisiana; and esophageal cancer in coastal South Carolina. The lung cancer investigations revealed elevated risks among several occupational groups, including shipyard workers in New Jersey and construction workers in Louisiana and Texas. Smoking of hand-rolled cigarettes was linked to the exceptionally high risk of lung cancer among Cajuns in southern Louisiana. Preliminary analyses from South Carolina showed that esophageal cancer risk is strongly increased among heavy users of alcohol, especially moonshine, but that low intake of fruits and vegetables also contributes to elevated mortality from this tumor. Several international studies are underway to take advantage of unique opportunities to evaluate diet and other factors, including air pollution, in the etiology of cancer. Interviewing was completed for case-control studies of cancers of the esophagus, stomach, and lung and choriocarcinoma in areas of China at high risk of these cancers, while a case-control study of gastric cancer was initiated in areas of Italy that have among the world's highest rates of this malignancy. Also in operation is a randomized intervention trial in Linxian, China, where up to one in four persons dies of esophageal cancer, to assess the role of vitamin/mineral supplementation on reducing this extraordinarily high cancer risk.