Lung cancer risk and residence in the neighborhood of a sewage plant in Italy. A case-control study.

Abstract

Environmental pollution originating in sewage and industrial plants can be associated with lung cancer risk, as ecological and case-control studies have indicated. In the present study, the association between lung cancer occurrence and residence near a sewage plant in Prato (Italy) was investigated. A previous geographic study in the same area had shown an increasing trend of lung cancer mortality and incidence with propinquity to the plant. A case-control study was carried out in the male population of Prato. Incident cases in the period 1987-1997 were identified from the Tuscan Cancer Registry (no. 918). Controls were randomly extracted from the Registry Office of the Municipality of Prato (no. 1852). For all subjects, the residential history was reconstructed. A weighted average distance from the plant was computed and used as a proxy variable of exposure. Two analyses were performed: on the whole data set and on a subset of subjects for whom information on tobacco exposure and education was obtained through a postal questionnaire (response rate, 41.1%). Logistic regression models were applied to estimate odds ratios and 95% CI. Both analyses showed a significantly elevated lung cancer risk for subjects living within 1.5 km (ORwhole= 1.56, 1.06-2.28; ORsubset= 2.28, 1.06-4.86) and suggested a risk increase with a decrease of weighted average distance from the plant. The findings highlight a possible role, in lung cancer occurrence, for environmental pollution spread from the plant. Due to drawbacks of the study, further analyses are needed to evidence a noncontroversial etiological conclusion. When environmental data are not available, results of epidemiological studies using residential histories may be useful in preventive policies regarding point source emissions.