Historically, the difficulty in epidemiologic studies has been that the only available air pollution data originated from central regional ambient sites, which may not be representative of personal exposures, resulting in imprecise associations.
Data include 376 person-days of daily endotoxin data collected from PM2.5 quartz filters using personal exposure monitors operated at 4 L/min, daily ambient endotoxin measurements collected from central ambient sites, and daily indoor and outdoor home endotoxin measurements in a subset of 14 children at 12 residential sites in Riverside and Whittier, California.
As described in Table 1, these included 97 ambient, 109 indoor and 101 outdoor home filters, and 10 filters from a site in Whittier that served as both an outdoor home and ambient site during one 10-day run, and served as the central ambient site for remaining 10-day runs.
In our study, exposures were estimated using concentrations measured at several ambient monitoring sites for CO, NO and NO2 and at a single ambient monitoring site for BC, which will not capture spatial variation in air pollutant concentrations.
We also assayed endotoxin in PM2.5 samples collected from ambient regional sites (N = 97 days) and from a subset of 12 indoor and outdoor subject home sites (N = 109 and 111 days, respectively) in Riverside and Whittier, California.
Using repeated (N = 9) measures personal exposure monitoring and determinants of exposure modeling, we compared daily average PM2.5, PM10, PM2.5 absorbance and NO2 concentrations measured at ambient monitoring sites to measures of personal exposures for (N = 64) caregivers of young children from high and low socioeconomic groups in two districts (urban and peri-urban), across two seasons.
These health studies often use air pollution measurements from central ambient monitoring sites as exposure surrogates.
The observed (measured) concentrations at the ambient monitoring sites were then compared with the values predicted by kriging.
To address this issue, we accessed OC monitoring data from the Aerosol Research and Inhalation Epidemiology Study ARIESS) and Texas ARIES ambient monitoring sites, located in Atlanta, GA, Birmingham, AL, and Dallas, TX.
High interpollutant correlations at ambient monitoring sites also make it difficult to identify independent associations from different regulated criteria air pollutants such as PM2.5 and nitrogen dioxide.
Ambient monitoring sites were established on the rooftop of a representative school in both southwest and eastside Detroit to assess community-level exposures to PM and O3.
