Household air pollution associated with different heating approaches in rural Northern China.

Household air pollution from solid fuel use remains a major health threat in low- and middle-income regions, yet real-world evidence on affordable transitional energy solutions is limited. While full electrification could eliminate this problem, its high costs remain impractical for the billions who still rely on solid fuels. Here, leveraging China's Clean Heating Initiative across 948 rural households in the North China Plain, we evaluated pelletized biofuels as a cleaner heating alternative through year-round PM2.5 monitoring, exposure modeling, and cost-benefit analysis. The annual indoor PM2.5 concentration was 109 ± 207 μg/m3, exceeding WHO guidelines for >90% of the year. Compared with traditional solid fuels, pelletized biofuel use was associated with 20%-30% lower indoor PM2.5 concentrations, ∼20% lower population exposure, and an estimated 8% lower attributable premature mortality in the study population. The benefit-to-cost ratio ranged from 4.39 to 8.64 for pelletized biofuels, compared with 0.76 to 2.20 for full electrification, with the advantage driven by substantially lower costs. At the regional level, transitioning to pelletized biofuels was estimated to reduce indoor PM2.5 concentrations and exposure by approximately 10% at a substantially lower cost than electric heating. This study provides large-scale field-based evidence that pelletized biofuels can serve as a cost-effective transitional heating solution for improving indoor air quality, offering actionable insights for other low- and middle-income countries.