Abstract:
Household air pollution from the combustion of solid fuels is a leading global health
and human rights concern, affecting billions every day. Instrumentation to assess potential solutions
to this problem faces challenges—especially related to cost. A low-cost ($159) particulate matter tool
called the Household Air Pollution Exposure (HAPEx) Nano was evaluated in the field as part of
the Prices, Peers, and Perceptions cookstove study in northern Ghana. Measurements of temperature,
relative humidity, absolute humidity, and carbon dioxide and carbon monoxide concentrations
made at 1-min temporal resolution were integrated with 1-min particulate matter less than 2.5
microns in diameter (PM2.5 ) measurements from the HAPEx, within 62 kitchens, across urban
and rural households and four seasons totaling 71 48-h deployments. Gravimetric filter sampling
was undertaken to ground-truth and evaluate the low-cost measurements. HAPEx baseline drift
and relative humidity corrections were investigated and evaluated using signals from paired
HAPEx, finding significant improvements. Resulting particle coefficients and integrated gravimetric
PM2.5 concentrations were modeled to explore drivers of variability; urban/rural, season, kitchen
characteristics, and dust (a major PM2.5 mass constituent) were significant predictors. The high
correlation (R2 = 0.79) between 48-h mean HAPEx readings and gravimetric PM2.5 mass (including
other covariates) indicates that the HAPEx can be a useful tool in household energy studies.
