Sugarcane farming--is there a link with cancer?

In the United States, there is an epidemic of lung cancer, which causes more deaths annually than any other form of cancer. During 1950-1969, 27 of Louisiana's 64 parishes ranked in the upper 100 US countries for lung cancer mortality. Many of the rural southern parishes in the upper decile for lung cancer were geographically associated with sugarcane production and processing area. In a retrospective case-control study of this excess lung cancer mortality it was found that persons engaged in sugarcane farm-related occupations have a significantly increased risk of mortality due to this disease. To expand this observation, a survey of the environmental exposures of sugarcane workers is being conducted.