Relationship between respiratory cancer and wetlands residency in Louisiana.

Cancer mortality is high among white men residing in southern Louisiana parishes (counties). In an effort to elucidate this phenomenon, we studied three environmental correlates of cancer-namely, smoking, residence in urban communities, and residence in the wetlands. Multiple regression analysis was applied to cancer mortalities adjusted for age and urban residency, and specific for race, sex, amount of standing water area in the parish, and cancer site. Cancer sites were grouped according to their correlation with smoking: strong, moderate, and no correlation. For men, the smoking-related cancer mortality not only showed an association with residence in wetlands but also was higher in the Louisiana wetlands than in the remainder of the United States.