| The association of exposure to wood smoke from cooking with low birth weight (LBW) and fatal birth outcomes was studied using comparison to natural gas (NG) users, in a historical cohort of women living in a semi-rural area of southern Pakistan.; Birth records from 2000 to 2002 and interviews conducted with all women who delivered 2000-2002 and still lived in the study area in 2005 (n=636) characterized fuel use and exposure to fuel smoke and determined fatal birth outcomes. The sample of participants for exposure measurement (n=95) was selected from strata based on fuel type (wood or natural gas) and median monthly income. Exposure to CO and PM2.5 was measured using electrochemical data loggers for CO and a DUSTRAK spectrometer for PM2.5.; Multiple regression analyses were performed to estimate the risk of LBW and first reported fatal infant outcome and reduced mean birth weight. Propensity scores were computed and used to adjust for multiple confounders related to use of wood.; The adjusted relative risk of LBW was 1.64 (95% CI 1.10, 2.34) associated with wood use during pregnancy, compared to NG users, with a population attributable risk of 24%. Infants born to wood users on average were 82 g lighter (95% CI -0.17, 0.009) than infants horn to NG users, adjusting for confounders. Cooking with wood, compared to NG, fuel was associated with fetal and neonatal deaths (AOR 1.95, 95% CI 1.08, 3.61). In the sub-sample in whom exposure was measured, geometric mean concentrations of CO and PM2.5 in wood users were 19.7 (GSD12.1) ppm and 0.19 (GSD 0.22) mg/m3, respectively, compared to 5.4 (GSD 3.3) ppm and 0.03 (GSD 0.02) mg/mg3, respectively, in NG users (p<0.001). Using the EPA standard (9 ppm/8h for CO and 65mug/24h for PM2.5), CO exposure was exceeded in 88% of wood users compared to 27% of NG users; PM2.5 exposure was exceeded in 82% of wood users compared to 18% of NG users.; Discontinuation of wood fuel and improvement in removal of their pollutants from households has the potential to reduce adverse infant birth outcomes. |
