Figure 1From: A cross-sectional study of determinants of indoor environmental exposures in households with and without chronic exposure to biomass fuel smoke Plot of log-transformed gravimetric PM 2.5 concentrations vs. log-transformed passive nephelometric PM concentrations. The red line represents the calibration equation: Gravimetric PM2.5 = e 1.5 + 0.6 × ln(nephelometric PM).Back to article page