Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August-1 September 2010: Air Pollution - Indoor Air Quality and Health Effects
1Harvard School of Public Health, Boston, MA; and 2Medical Research Council Laboratories, Fajara, Gambia.
Abstracts published in Epidemiology have been reviewed by the societies at whose meetings the abstracts have been accepted for presentation. These abstracts have not undergone review by the Editorial Board of Epidemiology.
Smoke from biomass fuels contains multiple gaseous and particulate pollutants, and is a risk factor for pneumonia, the leading cause of child death worldwide. Few studies have assessed the exposure-response relationship for biomass smoke and pneumonia, primarily because measuring children's exposure is difficult, especially for particulate matter (PM). We report on a study which utilized multiple methods to evaluate children's exposure to PM and carbon monoxide (CO) from biomass fuels.
Seventy-two hours personal CO exposure was measured for 1200 children, with 12%–15% receiving an additional 3–4 CO measurements. In the same subset of children, 72-hours integrated and continuous PM and 72-hours CO were measured in the cookhouse. Personal PM exposure was measured for 20–25 of these children. Usual personal exposure to CO is estimated using a random effects model including child- and household-level covariates. Personal exposure of children to PM is estimated using 3 different approaches, as well as a combined model: (1) combining time-location-activity budget with microenvironment PM; (2) estimating PM exposure using CO exposure combined with stationary CO-PM relationship; and (3) direct measurement of personal PM.
Preliminary results show a mean 72-hours CO exposure on children of 1.0 ± 1.3 ppm, with an age distribution of 0.8 ± 0.9 ppm (0–11 months) and 1.1 ± 1.5 ppm (12–59 months). Regression analysis adjusting for child's age, study site, and sex indicates a seasonal pattern for CO exposure, with significantly higher exposure in July, August, and September. Using the CO-PM relationship from a pilot study, estimated average personal PM2.5 exposure for these children would be 189 μg/m3.
Children's exposure to PM2.5 in The Gambia is well above WHO Air Quality Guidelines. The results of multiple measurement methods can be combined to estimate children's personal PM2.5 exposure.