Sociodemographic descriptors of personal exposure to fine particles (PM2.5) in EXPOLIS Helsinki

Demographic and socioeconomic differences between population sub-groups wer e analyzed, as a component of the EXPOLIS (Air Pollution Exposure Distribut ions Within Adult Urban Populations in Europe) Helsinki study, to explain v ariation in personal exposures to fine particles (PM2.5). Two-hundred one i ndividuals were randomly selected among 25-55-year-old inhabitants of Helsi nki Metropolitan area. Personal exposure samples and residential indoor, re sidential outdoor and workplace indoor microenvironment measurements of PM2 .5 were collected between October 1996 and December 1997. Variation in PM2. 5, personal exposures, between sociodemographic sub-groups, was best descri bed by differences in occupational status, education and age. Lower occupat ional status, less educated and young participants had greater exposures th an upper occupational status, more educated and older participants. Differe nt workplace concentrations explained most of the socioeconomic differences , and personal day and night exposures and concentrations in home (but not workplace or outdoor concentrations) caused the PM2.5 exposure differences between age groups. Men had higher exposures and much larger exposure diffe rences between the sociodemographic groups than women. No gender, socioecon omic or age differences were observed in home outdoor concentrations betwee n groups. Exposure to tobacco smoke did not seem to create new differences between the sociodemographic groups; instead, it amplified the existing dif ferences.