Asthma Disparity Among Californians
This page last reviewed March 15, 2011
Is Disparity in Asthma Among Californians Due to Higher Pollution Exposures, Greater Susceptibility, or Both?
Dr. Ying-Ying Meng Principal Investigator
Dr. John Balmes Co-Investigator
Dr. Beate Ritz Co-Investigator
Dr. Michelle Wilhelm Co-Investigator $299,794 (24 months)
Despite major advances in the development of anti-inflammatory medications, children, the elderly, minorities and low-income Californians suffer disproportionately from asthma and asthma-like symptoms. CHIS (California Health Interview Survey) is a two-stage, geographically stratified random-digit-dial (RDD) telephone survey that has been conducted biannually since 2001. A previous CDC-funded study linking 2001 CHIS and ambient air monitoring and traffic data in Los Angeles and San Diego counties found that individuals living near heavy traffic or in areas with high ozone and PM10 levels were more likely to report chronic severe asthma or acute asthma exacerbations. However, the study data was too limited to perform a meaningful sub-population analysis, such as assessing the impacts of race/ethnicity and related vulnerability factors on the pollutant–asthma outcome associations. CHIS 2003 collected information on approximately 54,500 non-institutionalized Californians, including 12,500 children. CHIS 2003 provides better information on residential location, housing conditions, indoor exposures, health behaviors, and asthma outcome measures than CHIS 2001.
This study will use CHIS 2003 data to characterize air pollution exposures at respondent residence locations. Exposure assessment will include estimations of annual average concentrations of ozone, PM10, PM2.5 and NO2 from the nearest monitoring station (within a 10 km radius). For respondents living in rural areas with fewer monitoring stations, the investigators will interpolate concentrations based on a maximum of three monitoring stations. Based on previous work, 50 km was used as the maximum interpolation radius. They will evaluate the impacts of distance and number of monitoring stations on the interpolations results. They will also calculate exceedance frequencies (e.g., number of days or hours above a certain cut-off point for each pollutant). This study will also develop residential annual traffic density measures and distance to major roadways/freeways measures using data from the California Department of Transportation (Caltrans) for each CHIS 2003 respondent. The study will identify sensitive sub-populations (by income levels, age, gender, rural/urban residency, and race/ethnicity) that have higher exposures to a single pollutant or pollutant mixes. Then it will determine whether the disproportionate burden of asthma or asthma-like symptoms among low socio-economic status individuals is associated with greater pollutant exposures, greater vulnerabilities, or both, compared to the general population. The findings of this project will contribute to our current understanding of the link between air pollution and asthma. The results from this study are expected in fall 2009.
ARB Kick off meeting presentation by Dr. Meng
For more information, please contact Dr. Barbara Weller at (916) 324-4816.