Respiratory function as measured by peak expiratory flow rate and PM₁₀: Six communities study

This Six Communities Study conducted at six communities in southwestern North Carolina investigates the respiratory health status of residents whose households are located near an incinerator. This diary study makes it possible to estimate the daily variation of pulmonary function measured as peak expiratory flow rate (PEFR) related to 24-h mean PM₁₀ levels, which were observed at each monitoring station placed in the six study communities, as a surrogate exposure measure of outdoor air pollution. Observations of PEFR among participants in each community were analyzed to determine how they varied according to the degree of exposure to ambient pollutants as well as to other cofactors including, sex, age, respiratory hypersensitivity, hours spent outdoors within the area of the selected community, and surrogate measures for indoor air pollution exposure (vacuum use and experience of air irritants at work). The findings revealed that respiratory hypersensitivity status is a predictor of declining PEFR. PM₁₀ concentrations measured in each study area did not seem to be related to the variations of respiratory health as measured by PEFR. This study did not show any difference in respiratory health between subjects of an incinerator community and those of its comparison community. Even though this community-based study with free- living subjects shows negative findings on the relationship between respiratory health and PM₁₀, it is worth noting that these findings must be interpreted cautiously because exposure estimation based on monitoring of ambient air likely results in misclassification of true exposure levels.