Smoking increases air pollution levels in city streets: observational and fine particulate data.

INTRODUCTION To address the paucity of research around smokefree streets, we: (i) refined existing data collection methods; (ii) expanded on the meagre previous research in this area; and (iii) compared results by differing size of urban centre. METHODS We refined established methods; a solo observer simultaneously observed smoking and measured fine particulate levels (PM(2.5)) on a route of shopping streets in central Lower Hutt City, New Zealand. RESULTS Over 33.6 h of measurement, mean fine particulate levels were 1.7 times higher when smoking was observed than when it was not (7.9 vs 4.8 μg/m(3); p=0.0001). CONCLUSIONS Smoking appeared to be a substantive contributor to fine particulate air pollution in city streets, when compared to levels adjacent to road traffic.