Table 4: Relationship between the predicted Sindoor/Soutdoor ratio and household characteristics and behaviors.

From: Development of a modeling approach to estimate indoor-to-outdoor sulfur ratios and predict indoor PM2.5 and black carbon concentrations for Eastern Massachusetts households

 EstimateStd. errort-valueP-value
Heat fuel
 Other/oil vs gas/electric0.070.0203.1650.001
 Open vs closed0.100.0204.340<0.001
Road density0.030.0171.7900.07
Electric space heater use0.0030.0300.0960.92
Forced-air heating use
 Yes vs no−0.060.030−1.9300.05
Land cover
 Urban vs rural0.200.0434.477<0.001
Air purifier use
 Yes vs no−0.280.095−2.8840.004
Air conditioning use
 Yes vs no−0.060.026−2.3960.017