Around one-quarter of the global population, mainly in low- and middle-income countries, still relies on biomass cookstoves, which produce high levels of harmful air pollutants that negatively affect both human health and the environment. This study systematically reviewed scientific literature on aerosol and particle emissions from biomass cookstoves, analysing 187 peer-reviewed articles. Most studies were published after 2010, with field studies concentrated in Asia and laboratory studies largely conducted in North America.

The study found that although improved and advanced cookstoves generally emit less particles than traditional stoves, most biomass cookstoves still fall into the World Health Organization’s polluting or transitional categories. Additionally, it is important to note that emission factors measured in real world field studies were consistently higher than those measured under laboratory conditions, highlighting a gap between controlled testing and actual use.

The study emphasizes that evaluating particle matter alone is insufficient to assess health and environmental impacts, as there are still major gaps in understanding what harmful particles from cookstoves are made of and how different fuels affect the air pollution people are exposed to. Finally, the authors conclude that current global cookstove policies do not adequately reflect scientific evidence on particle properties, underscoring the need for a stronger integration of science into policy to support cleaner and more sustainable biomass cooking solutions.