Figure 6.

Percent of personal exposure samples within different ${\mathrm{PM}}_{2.5}$ concentration ranges by minute of a day for the intervention group (B,D,F) and control group (A,C,E) at baseline (A,B), at follow-up samples taken at the 3-, 6-, 12-month time points (C,D) and at 18-, and 24-month time points (E,F) in rural Peru. Samples $<\text{LOD}$ were replaced by $\text{LOD}/\sqrt{2}$$7\mathrm{\mu }\mathrm{g}$ for ${\mathrm{PM}}_{2.5}$ gravimetric integrated samples, respectively. The sample size for baseline, 3-, 6-, 12, 18-, and 24-month visits for control and intervention households are: ${\mathrm{n}}_0=90$ and 90, ${\mathrm{n}}_3=87$ and 90, ${\mathrm{n}}_6=90$ and 89, ${\mathrm{n}}_{12}=90$ and 87, ${\mathrm{n}}_{18}=90$ and 88, ${\mathrm{n}}_{24}=85$ and 84. During the second year (follow-up visits:18- and 24 months) the control participants received the LPG stove intervention and vouchers for 1-y supply of free fuel and intervention participants stopped receiving free fuel but kept the LPG stove. Note: LOD, limit of detection; LPG, liquefied petroleum gas.