Chimney stoves modestly improved indoor air quality measurements compared with traditional open fire stoves: results from a small-scale intervention study in rural Peru

Abstract

Nearly half of the world's population depends on biomass fuels to meet domestic energy needs, producing high levels of pollutants responsible for substantial morbidity and mortality. We compare carbon monoxide (CO) and particulate matter (PM2.5) exposures and kitchen concentrations in households with study-promoted intervention (OPTIMA-improved stoves and control stoves) in San Marcos Province, Cajamarca Region, Peru. We determined 48-h indoor air concentration levels of CO and PM2.5 in 93 kitchen environments and personal exposure, after OPTIMA-improved stoves had been installed for an average of 7 months. PM2.5 and CO measurements did not differ significantly between OPTIMA-improved stoves and control stoves. Although not statistically significant, a post hoc stratification of OPTIMA-improved stoves by level of performance revealed mean PM2.5 and CO levels of fully functional OPTIMA-improved stoves were 28% lower (n = 20, PM2.5, 136 μg/m(3) 95% CI 54-217) and 45% lower (n = 25, CO, 3.2 ppm, 95% CI 1.5-4.9) in the kitchen environment compared with the control stoves (n = 34, PM2.5, 189 μg/m(3), 95% CI 116-261; n = 44, CO, 5.8 ppm, 95% CI 3.3-8.2). Likewise, although not statistically significant, personal exposures for OPTIMA-improved stoves were 43% and 17% lower for PM2.5 (n = 23) and CO (n = 25), respectively. Stove maintenance and functionality level are factors worthy of consideration for future evaluations of stove interventions.

Keywords: Carbon monoxide; Household air pollution; Improved chimney stoves; Particulate matter; Peru.

Figure 1

48 hr PM2.5 and CO mean concentrations between traditional and OPTIMA-improved stove for kitchen environment and personal exposure Control Stoves: include all control households, (open fires, Self-improved by household and NGO). OPTIMA Improved: includes all OPTIMA-improved stoves functionality levels (FL-I and FL-II)

Figure 2

48hr PM 2.5 and CO concentration in OPTIMA-improved households separated into functionality levels. OPTIMA Improved: includes all OPTIMA-improved stoves functionality levels (FL-I and FL-II) FL-I: stoves in good running conditions (plastered stove and no visible leaks when in use) FL-II: stove in need of repairs (re-plastering, filling cracks)