Student Research: Michael Box
, , 2000
Exposure to Particulate Matter Among Older Adults with Chronic Obstructive Pulmonary Disease: Relation Between Personal, Indoor, and Outdoor Concentrations
Recent research has indicated that changes in daily mortality have been correlated with daily PM10 and PM2.5 levels below the current 24 hour National Ambient Air Quality Standards (NAAQSs) for PM10 in the United States. As a result, new NAAQSs for PM2.5 were recommended. A question that remains however, is whether there is a relationship between personal exposures among high-risk subpopulations and particulate matter (PM) concentrations measured at a regional monitoring site.
This thesis is part of a comprehensive 3-year exposure assessment study that is examining the health effects of PM in individuals with chronic obtrusive pulmonary disease (COPD) and cardiovascular diseases, as well as healthy control subjects. The primary objective of this thesis was to determine the relationships between personal, indoor, outdoor, and regional monitoring site PM exposures among COPD subjects and healthy controls in the Seattle area. Seventeen COPD and seventeen healthy subjects living in private or group homes participated in the monitoring sessions in the fall of 1999 and winter of 2000. Personal, indoor, and outdoor PM10, PM2.5 and CO were monitored for 10 consecutive days for each subject. Harvard impactors (HI) were used for PM2.5 and PM10 measurements at indoor, outdoor and regional monitoring sites, while Harvard personal environmental monitors (HPEM) were used for personal PM2.5 monitoring. The secondary objective of this thesis was to determine the accuracy and precision of the HI and HPEM in a field setting.
The HI2.5 was determined to be very accurate in a field setting when it was collocated with the Federal Reference Method (R2=0.98, slope=0.95, p<0.001, n=27). The coefficient of variation for duplicates of the HI2.5 was 5.1 percent. The average daily PM2.5 outside the individual home sites was significantly correlated with PM2.5 measured at the regional monitoring site on Beacon Hill (r=0.96, p<0.001). The indoor and outdoor levels of PM2.5 were also correlated (r=0.45, p<0.001). However, personal exposures to PM2.5 were poorly correlated with indoor PM2.5 (r=0.25, p=0.01) and PM2.5 measured at Beacon Hill (r=0.29, p=0.18). As a result of this study we have a better understanding of the relationships between personal, indoor, outdoor, and regional monitoring site PM concentrations.