Air pollution effects on the respiratory health of the resident adult population in Turin, Italy.

A case-control study was employed to investigate the relationship between atmospheric pollution and emergency hospital attendance for respiratory causes among adult and elderly patients resident in Turin in the period 1997 - 1999. Based on the primary diagnosis, adult (15 - 64 years) and elderly (>64 years) patients resident in Turin and admitted for respiratory causes were defined as Cases (n1 = 4.645); adult and elderly patients admitted for causes other than respiratory diseases or heart diseases were defined as Controls (n2 = 152.954). Sulfur dioxide (SO2 in microg/m3), total suspended particulate (TSP in microg/m3) and carbon monoxide (CO in mg/m3) were taken as indicators of urban air pollution; principal confounding factors were patient sex, age and education level; season, temperature, humidity, solar radiation; day of hospital admission. Statistical analysis was performed using logistic regression models. In accordance with Odds Ratio (OR) values and relative 95% Confidence Intervals (OR_95% CI) estimated by the models, associations are expressed as percent increase in risk (Increase%)1 and relative 95% Confidence Interval (95% CI) per 10 microg/m3 in SO2 and TSP, and per 1 mg/m3 in CO exposure. After adjusting for confounding factors, there was a mean increase in emergency hospital attendance of 2.20% (95% CI 1.70 - 2.60) and 2.55% (95% CI 1.79 - 3.32) per 10 microg/m3 increase in exposure to SO2 and TSP, respectively, and a mean increase of 5.30% (95% CI 3.00 - 7.70) per 1 mg/m3 increase in exposure to CO. A significant association was separately confirmed for SO2 and TSP in adult (15 - 64 years) and elderly (>64 years) patients, but for CO only among elderly patients. A significant association was found between the increase in emergency hospital attendance for respiratory causes and exposure to sulfur dioxide, total suspended particulate and carbon monoxide in Turin during the study period. This easy to use and manage case-control study produced results in line with those reported for other Italian and European cities.