Associations between personal exposures and fixed-site ambient measurements of fine particulate matter, nitrogen dioxide, and carbon monoxide in Toronto, Canada.
A longitudinal study investigating personal exposures to PM(2.5), nitrogen dioxide (NO(2)), and carbon monoxide (CO) for cardiac compromised individuals was conducted in Toronto, Canada. The aim of the study was (1) to examine the distribution of exposures to PM(2.5), NO(2), and CO; and (2) to investigate the relationship between personal exposures and fixed-site ambient measurements of PM(2.5), NO(2), and CO. In total, 28 subjects with coronary artery disease wore the Rupprecht & Patashnick ChemPass Personal Sampling System one day a week for a maximum of 10 weeks. The mean (SD) personal exposures were 22 microg m(-3) (42), 14 p.p.b. (6), and 1.4 p.p.m (0.5) for PM(2.5), NO(2), and CO, respectively. PM(2.5) and CO personal exposures were greater than central fixed-site ambient measurements, while the reverse pattern was observed for NO(2). Ambient PM(2.5) and NO(2) were correlated with personal exposures to PM(2.5) and NO(2) with median Spearman's correlation coefficients of 0.69 and 0.57, respectively. The correlations between personal exposures and ambient measurements made closest to the subjects' homes or the average of all stations within the study were not stronger than the correlation between personal exposures and central fixed-site measurements. Personal exposures to PM(2.5) were correlated with personal exposures to NO(2) (median Spearman's correlation coefficient of 0.43). This study suggests that central fixed-site measurements of PM(2.5) and NO(2) may be treated as surrogates for personal exposures to PM(2.5) and NO(2) in epidemiological studies, and that NO(2) is a potential confounder of PM(2.5).
Kim
David
D
Department of Environmental Sciences and Engineering, The University of North Carolina at Chapel Hill, North Carolina 27599-7431, USA.
Sass-Kortsak
Andrea
A
Purdham
James T
JT
Dales
Robert E
RE
Brook
Jeffrey R
JR
D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis; D002248:Carbon Monoxide / Q000032:analysis*; D015986:Confounding Factors, Epidemiologic; D003327:Coronary Disease; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D005260:Female; D005374:Filtration; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000032:analysis*; D009864:Ontario; D010316:Particle Size; D018709:Statistics, Nonparametric
D000393:Air Pollutants; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide