Impact of the improved patsari biomass stove on urinary polycyclic aromatic hydrocarbon biomarkers and carbon monoxide exposures in rural Mexican women.

BACKGROUND: Cooking with biomass fuels on open fires results in exposure to health-damaging pollutants such as carbon monoxide (CO), polycyclic aromatic hydrocarbons (PAHs), and particulate matter. OBJECTIVE: We compared CO exposures and urinary PAH biomarkers pre- and postintervention with an improved biomass stove, the Patsari stove. METHODS: In a subsample of 63 women participating in a randomized controlled trial in central Mexico, we measured personal CO exposure for 8 hr during the day using continuous monitors and passive samplers. In addition, first-morning urine samples obtained the next day were analyzed for monohydroxylated PAH metabolites by gas chromatography/isotope dilution/high-resolution mass spectrometry. Exposure data were collected during the use of an open fire (preintervention) and after installation of the improved stove (postintervention) for 47 women, enabling paired comparisons. RESULTS: Median pre- and postintervention values were 4 and 1 ppm for continuous personal CO and 3 and 1 ppm for passive sampler CO, respectively. Postintervention measurements indicated an average reduction of 42% for hydroxylated metabolites of naphthalene, fluorene, phenanthrene, and pyrene on a whole-weight concentration basis (micrograms per liter of urine), and a 34% reduction on a creatinine-adjusted basis (micrograms per gram of creatinine). Pre- and postintervention geometric mean values for 1-hydroxypyrene were 3.2 and 2.0 µg/g creatinine, respectively. CONCLUSION: Use of the Patsari stove significantly reduced CO and PAH exposures in women. However, levels of many PAH biomarkers remained higher than those reported among smokers.

Improved biomass stove intervention in rural Mexico: impact on the respiratory health of women.

RATIONALE: Exposure to biomass smoke has been related to adverse health effects. In Mexico, one household in four still cooks with biomass fuel, but there has been no evaluation of the health impact of reducing indoor air pollution. OBJECTIVES: To evaluate the health impact of the introduction of an improved biomass stove (Patsari; Interdisciplinary Group for Appropriate Rural Technology [GIRA], Patzcuaro, Mexico) in Mexican women. METHODS: A randomized controlled trial was conducted in the Central Mexican state of Michoacán. Households were randomized to receive the Patsari stove or keep their traditional open fire. A total of 552 women were followed with monthly visits over 10 months to assess stove use, inquire about respiratory and other symptoms, and obtain lung function measurements. Statistical analysis was conducted using longitudinal models. MEASUREMENTS AND MAIN RESULTS: Adherence to the intervention was low (50%). Women who reported using the Patsari stove most of the time compared with those using the open fire had significantly lower risk of respiratory symptoms (relative risk [RR], 0.77; 95% confidence interval [CI], 0.62-0.95 for cough and RR, 0.29; 95% CI, 0.11-0.77 for wheezing) adjusted for confounders. Similar results were found for other respiratory symptoms as well as for eye discomfort, headache, and back pain. Actual use of the Patsari stove was associated with a lower FEV(1) decline (31 ml) compared with the open fire use (62 ml) over 1 year of follow-up (P = 0.012) for women 20 years of age and older, adjusting for confounders. CONCLUSIONS: The use of the Patsari stove was significantly associated with a reduction of symptoms and of lung function decline comparable to smoking cessation.