Biogas and Household Air Quality: Impact of biogas stoves versus wood-fired stoves in Rural Cambodia.

This study showed that biogas reduces PM2.5 levels, with a reduction of around 36% reduction in exposure and 88% reduction in kitchen concentrations. CO levels are also much lower, but in most cases, including the baseline households lower than the 24-hour WHO guidelines. Short-term exposure to CO (≤ 1 hour) however remained too high for almost a quarter of the baseline households. It was also able to provide evidence that biogas stoves result in decreased PM2.5 and CO emissions; and that the high levels of HAP in biogas households may be attributable to the ambient air pollution. The study therefore concludes that biogas is a part of the solution to address HAP, but that the current scale and the focus on clean energy for cooking alone is not sufficient to bring the overall levels of PM2.5 near the WHO guidelines.