Women exposure to household air pollution after an improved cookstove program in rural San Luis Potosi, Mexico.

The state government of San Luis Potosí (SLP), Mexico implemented an improved cookstove (ICS) program in rural areas. As part of the comprehensive program evaluation, we compared fine particulate material (PM2.5) concentrations in kitchens and patios in treated (TH), and non-treated households (NTH), and analyzed pollutant levels according to patterns of fuels and devices use reported by the women. A panel study was conducted in 728 households (357 TH and 371 NTH) in three regions of SLP including two sampling rounds in 2015-16. Data on exposure determinants, ICS conditions and cooking practices were collected. Daily PM2.5 in kitchen and patio was measured in a subsample. The average treatment effect was estimated using the double difference method. We constructed a mixed linear model to estimate PM2.5 levels for the entire study sample and obtained personal exposure according to time-activity logs. NTH had lower socioeconomic status compared to TH. The average daily PM2.5 concentrations in NTH compared to TH were 155.2 and 92.6 μg/m3 for kitchen and 35.4 and 39.8 μg/m3 for patio, respectively. PM2.5 levels showed significant regional differences but no significant treatment effect. In many cases, the ICS was added to previous open fire and LPG use (stacking). The household size, kitchen ventilation, relative humidity, temperature and the ratio of indoor/outdoor PM2.5 concentration were significant predictors of kitchen PM2.5 levels. The daily PM2.5 personal exposure was significantly reduced using ICS in good conditions or LPG (57 μg/m3) compared to the traditional open fire (86 μg/m3). This study strengthens the evidence on the potential daily PM2.5 exposure reduction for women using an ICS in good conditions or LPG, displacing the polluting open fire. Comprehensive strategies tailored to the sociocultural context of the communities are needed to implement clean energy programs that achieve adoption and sustained use of ICS or LPG.