PRELIMINARY EVALUATION, USING PASSIVE TUBES, OF CARBON-MONOXIDE CONCENTRATIONS IN OUTDOOR AND INDOOR AIR AT STREET-LEVEL SHOPS IN GENOA (ITALY)

Preliminary information on carbon monoxide (CO) concentrations (exposu re time: 8 h) both inside and outside 38 randomly selected shops situa ted on four heavy traffic streets of Genoa was obtained using passive diffusion tubes. Reproducibility and accuracy of this analytical metho d were tested in real outdoor urban conditions and found within 25%; t he detection limit was 1 mg m(-3) of CO. The highest mean CO concentra tions (15.8 +/- 2.2 mg m(-3)) were found inside shops on Balbi street, a narrow ''canyon street''. Only in two small shops and two bars (bot h with many smokers) and in a delicatessen, were indoor CO concentrati ons significantly higher than outdoor values. The mean outdoor CO conc entrations (mg m(-3)) along the four streets considered (XX Settembre, Balbi, Rolando, Fillak) were 7.4 +/- 2.2; 14.5 +/- 8.7; 5.8 +/- 0.4; 10.5 +/- 3.7, respectively. No statistical difference was found, compa ring the mean indoor CO concentration with the mean CO outdoor value, measured simultaneously along the sidewalks of each street. CO concent rations in 10 shops without smokers and the nearest outdoor measuremen ts were linearly correlated (r = 0.99; p < 0.0001). No statistically s ignificant difference was found comparing indoor CO pollution in shops with smokers (CO: 8.0 +/- 5.4) to those without smokers (CO: 7.1 +/- 4.6). Forced ventilation, with air intake far from traffic, proved eff ective in some specific situations in reducing indoor CO concentration s. (C) 1997 Elsevier Science Ltd.