AIR-POLLUTION AND LUNG-CANCER IN TRIESTE, ITALY - SPATIAL-ANALYSIS OFRISK AS A FUNCTION OF DISTANCE FROM SOURCES

To investigate the relationship between four sources of environmental pollution (shipyard, iron foundry, incinerator, and city center) and l ung cancer risk, we conducted a case-control study of deceased men in Trieste, Italy. We identified 755 cases of lung cancer and 755 control s through the local autopsy registry. Information on smoking habits, o ccupational history, and place of residence were obtained from the sub jects' next of kin. The case-control design was used to properly accou nt for subject-specific confounders, which represent a major problem i n geographical analysis. Spatial models were used to evaluate the effe ct of sources of pollution on lung cancer after adjustment for age, sm oking habits, likelihood of exposure to occupational carcinogens, and levels of air particulate. The models are based on distance from the s ources and enable estimation of the risk gradient and directional effe cts separately for each source. The risk of lung cancer was highly rel ated to the city center (p = 0.0243), with an excess relative risk at zero distance of 2.2 and a smooth decrease moving away from the source (-0.015), and related to the incinerator (p = 0.0098), with an excess relative risk of 6.7 in the source and a very steep decrease (-0.176) . These results are consistent with findings of previous analyses and provide further evidence that air pollution is a moderate risk factor of lung cancer.