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Estimating Error in Using Ambient PM2.5 Concentrations as Proxies for Personal Exposures: A Review


Avery, Christy L.; Mills, Katherine T.; Williams, Ronald W.; McGraw, Kathleen A.; Poole, Charles L.; Smith, Richard L.; & Whitsel, Eric A. (2010). Estimating Error in Using Ambient PM2.5 Concentrations as Proxies for Personal Exposures: A Review. Epidemiology, 21(2), 215-223. PMCID: PMC5370079


BACKGROUND: Several methods have been used to account for measurement error inherent in using ambient concentration of particulate matter < 2.5 microm/m(3) (PM(2.5)) as a proxy for personal exposure. Such methods commonly rely on the estimated correlation between ambient and personal PM(2.5) concentrations (r). However, studies of r have not been systematically and quantitatively assessed for publication bias or heterogeneity.
METHODS: We searched 7 electronic reference databases for studies of the within-participant correlation between ambient and personal PM(2.5).
RESULTS: We identified 567 candidate studies, 18 (3%) of which met inclusion criteria and were abstracted. The studies were published between 1999 and 2008, representing 619 nonsmoking participants aged 6-93 years in 17 European and North American cities. Correlation coefficients (median 0.54; range 0.09-0.83) were based on a median of 8 ambient-personal PM(2.5) pairs per participant (range 5-20) collected over 27-547 days. Overall, there was little evidence for publication bias (funnel plot symmetry tests: Begg's log-rank test, P 0.9; Egger's regression asymmetry test, P 0.2). However, strong evidence for heterogeneity was noted (Cochran's Q test for heterogeneity, P = 0.001). European locales, eastern longitudes in North America, higher ambient PM(2.5) concentrations, higher relative humidity, and lower between-participant variation in r were associated with increased r.
CONCLUSIONS: Characteristics of participants, studies, and the environments in which they are conducted may affect the accuracy of ambient PM2.5 as a proxy for personal exposure.


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Journal Article

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Avery, Christy L.
Mills, Katherine T.
Williams, Ronald W.
McGraw, Kathleen A.
Poole, Charles L.
Smith, Richard L.
Whitsel, Eric A.