Exposures to nitrogen dioxide in EXPOLIS-Helsinki: microenvironment, behavioral and sociodemographic factors

Personal exposures to nitrogen dioxide (NO2) Were monitored for 176 randoml y selected inhabitants (25-55 years old) of Helsinki Metropolitan area as a part of the EAPOLIS (Air Pollution Exposure Distributions Within Adult Urb an Populations in Europe) study between October 1996 and December 1997. NO2 measurements were 48-h averages collected by Palmes passive sampler tubes. Differences in personal exposures to NO2 were analyzed between subpopulati ons stratified by microenvironment, behavioral, socioeconomic and demograph ic factors. Factors significantly associated with differences in exposures to NO2 were home and work location, housing characteristics, traffic volume near home, season and keeping windows open at home. Exposure to environmen tal tobacco smoke (ETS) and use of gas stove were also associated with incr eased personal exposures, although only few participants had a gas stove in Helsinki and other gas appliances are non-existent. Single adults had high er average exposures to NO2. than married or cohabiting participants, sugge sting differences in living conditions between these two groups. Increased education was associated with decreased exposures to NO2 and employed men w ere more exposed than unemployed men. Increased exposures to NO2 were not a ssociated with age or occupational status in Helsinki. Thus, behavioral and sociodemographic factors may have significant impact on personal exposures to NO2 and should be considered in addition to environmental determinants in any monitoring program.