Table 3.
Regression coefficients for multivariate analysis of the association of cooking area PM with sources, cooking area location, and meteorological covariates
| Model 1 |
Model 2 |
|||
| Variable | Coefficient (95% CI) | P value | Coefficient (95% CI) | P value |
| Dependent variable: ln (PM2.5) | n = 79; adjusted R2 = 0.68 | n = 79; adjusted R2 = 0.50 | ||
| Constant | 1.246 (0.610, 1.881) | <0.001 | 3.038 (2.704, 3.372) | <0.001 |
| ln (neighborhood average) | 0.517 (0.351, 0.683) | <0.001 | ||
| Households using biomass in the EA (%) | 0.004 (0.000, 0.008) | 0.03 | 0.010(0.006, 0.014) | <0.001 |
| Household size | 0.014 (−0.015, 0.043) | 0.35 | 0.000 (−0.035, 0.036) | 0.99 |
| Average distance to main roads (km) | 0.527 (−0.200, 1,254) | 0.15 | −0.143(−1.008, 0.722) | 0.74 |
| Household cooking fuel | ||||
| Nonbiomass | 0.0 | NA | 0.0 | NA |
| Biomass | 0.104 (−0.153, 0.362) | 0.42 | 0.174 (−0.146, 0.493) | 0.28 |
| Small commercial cooking fuel | ||||
| No commercial cooking | 0.0 | NA | 0.0 | NA |
| Nonbiomass | −0.093(−0.428, 0.242) | 0.58 | −0.116 (−0.533, 0.301) | 0.58 |
| Biomass | 0.211 (0.025, 0.396) | 0.03 | 0.255 (0.025, 0.486) | 0.03 |
| Cooking area | ||||
| Inside the house | 0.0 | NA | 0.0 | NA |
| Open air | −0.040(−0.342, 0.217) | 0.78 | −0.112 (−0.456, 0.231) | 0.52 |
| Separate cookhouse | −0.221(−0.536, 0.094) | 0.17 | −0.227 (−0.620, 0.165) | 0.25 |
| Secondhand smoke | ||||
| No smoker in the house | 0.0 | NA | 0.0 | NA |
| Smoker in the house | −0.053(-0.345, 0.239) | 0.72 | 0.160 (−0.193, 0.514) | 0.37 |
| Meteorological factor | ||||
| Raining duration (hours) | −0.000(−0.033, 0.032) | 0.98 | −0.024 (−0.063, 0.015) | 0.22 |
| Dependent variable: ln (PM2.5–10) | n = 77; adjusted R2 = 0.86 | n = 77; adjusted R2 = 0.60 | ||
| Constant | 1.049 (0.487, 1.611) | <0.001 | 3.903 (3.516, 4.289) | <0.001 |
| ln (neighborhood average) | 0.750 (0.615, 0.885) | <0.001 | ||
| Households using biomass in the EA (%) | 0.005 (0.002, 0.009) | 0.001 | 0.010 (0.005, 0.015) | <0.001 |
| Household size | 0.017 (−0.009, 0.042) | 0.19 | −0.022 (−0.064, 0.019) | 0.29 |
| Average distance to main roads (km) | −0.480 (−1.100, 0.139) | 0.13 | −1.522(−2.519, −0.525) | 0.003 |
| Household cooking fuel | ||||
| Nonbiomass | 0.0 | NA | 0.0 | NA |
| Biomass | 0.343 (0.126, 0.561) | 0.002 | 0.225 (−0.140, 0.591) | 0.22 |
| Small commercial cooking fuel | ||||
| No commercial cooking | 0.0 | NA | 0.0 | NA |
| Nonbiomass | 0.050 (−0.233, 0.334) | 0.72 | −0.012 (−0.490, 0.467) | 0.96 |
| Biomass | 0.103 (−0.054, 0.261) | 0.20 | 0.155 (−0.111, 0.421) | 0.25 |
| Cooking location | ||||
| Inside the house | 0.0 | NA | 0.0 | NA |
| Open air | −0.033(−0.266, 0.201) | 0.78 | 0.094(−0.299, 0.488) | 0.63 |
| Separate cook house | −0.144 (−0.411, 0.123) | 0.29 | 0.021 (−0.427, 0.468) | 0.93 |
| Secondhand smoke | ||||
| No smokers in the house | 0.0 | NA | 0.0 | NA |
| Smokers in the house | −0.098 (−0.338, 0.142) | 0.42 | −0.041 (−0.446, 0.364) | 0.84 |
| Meteorological factor | ||||
| Raining duration (hours) | −0.007 (−0.035, 0.021) | 0.62 | −0.063 (−0.108, -0.018) | 0.006 |
NA, not applicable. Model 1 is adjusted for neighborhood average PM concentrations at nontraffic rooftop sites and model 2 is not. See SI Text for details.