Evidence for space-time clustering of lung cancer deaths

One parish in Louisiana has the highest reported incidence of lung cancer in the United States. Statistically significant space-time clustering (P < 1.0) was present among lung cancer deaths (1960-1975) in residents of the urban portion of this parish. The spatial distribution of cancer deaths in the urban portion of the parish was compared to age, year of death, race, and sex matched control deaths to determine the risk of lung cancer associated with residential proximity to industry. For industries with independently increased risks, the combination of industries produced risks of 1.9 to 3.2 (P < .05) for residing within 1.2 km of one or more industries to three or more industries, respectively. The results suggest residential exposure to industrial effluents is a factor contributing to the rate of lung cancer.