204528 Assessing exposure metrics for air pollution and birthweight models in North Carolina

Monday, November 9, 2009: 3:20 PM

Simone C. Gray, BS, MS , Children's Environmental Health Initiative, Duke University, Durham, NC
Sharon Edwards, BA, MS , Children's Environmental Health Initiative, Duke University, Durham, NC
Marie Lynn Miranda, PhD , Children's Environmental Health Initiative, Duke University, Durham, NC
The link between air pollution (AP) exposure and adverse birth outcomes is of public health concern due to the relationship between poor pregnancy outcomes and the onset of childhood diseases. As personal exposure measures are difficult to obtain, proximate measures of AP exposure are traditionally used. We explore how different AP exposure metrics affect BWT regression models. We examined the impact of maternal exposure to ambient levels of PM10 and PM2.5 on BWT among infants in North Carolina (NC). We linked maternal residence to the closest monitor during pregnancy for 2000-2002 (n=350,754), restricting analyses to singleton births. We estimated exposure by averaging county level AP concentrations for the entire pregnancy and each trimester. For a finer spatially resolved metric, we calculated exposure averages for women living within 20, 10 and 5 km of a monitor. Multivariate linear regression was used to determine the association between AP exposure and BWT adjusting for standard covariates. In the county level model an interquartile increase in PM10 and PM2.5 during the entire pregnancy reduced BWT by 5.3g (95%CI=3.3-7.4) and 4.6g (95%CI=2.3-6.8) respectively. This model also reduced BWT for PM10 (7.1g, 95%CI=1.0-13.2) and PM2.5 (10.4g, 95%CI=6.4-14.4) during the third trimester. Proximity models for 20, 10 and 5 km distances showed results similar to the county level models. NC has relatively good air quality. Nevertheless, the sensitivity analysis showed that at various spatial resolutions there is still a negative association between AP and BWT, despite consistent attainment of federal air quality standards in the study area.

Learning Objectives:
1. List different air pollution exposure measures 2. Describe how different air pollution exposure methods affect the relationship between air borne particulate matter and birth weight. 2. List the health risk of air pollution exposure on pregnant women. 3. Describe the differences between exposure measures at various spatial resolutions.

Keywords: Air Quality, Low Birthweight

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am currently a PhD student at Duke and have been working on air pollution modeling for the past two years.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.