Between 2.3 and 3.2 million people die each year due to illnesses caused by the inhalation of indoor air pollution.1 The principal source of that pollution is the combustion of solid fuels (wood, crop waste, charcoal, coal, and dung) and kerosene in open fires and inefficient stoves. Exposure to particulate matter and other pollutants impairs the functions of the lungs, heart, and immune system. The major causes of premature deaths from such exposure are heart disease, stroke, chronic obstructive pulmonary disease (COPD), lung cancer, and other illnesses.
Deaths from indoor air pollution show tremendous geographic variation. In countries with high access to clean fuels and electricity, deaths from indoor air pollution generally account for much less than one percent of deaths from all causes. But the situation is far different in countries where people have no choice but to rely on solid fuels and inefficient technology. In 2019, there were 40 countries in which deaths from indoor air pollution accounted for 10% or more of deaths from all causes. These countries are concentrated in sub-Saharan Africa and south Asia.
Per capita income is closely associated with deaths from indoor air pollution. In 2019, no country classified as high-income by the World Bank had more than 1.3% of deaths from all causes attributed to indoor air pollution. The majority of countries classified as low income had more than 10% of deaths from all causes attributed to indoor air pollution.
The connection is very clear between access to clean energy and deaths from indoor air pollution. Countries with universal or nearly universal access to clean fuels for cooking have extremely low death rates from indoor air pollution: Germany (0.003%), Australia (0.08%), and Japan (0.01%). But death rates rise steadily as access to clean energy declines. Countries in which less than 50% of the population have access to clean cooking fuels generally have 6% to 20% of deaths from all causes resulting from exposure to indoor air pollution.
Tremendous progress has been made in reducing the health risks of indoor air pollution. To see this, play the animation in the chart above and watch the movement of many countries towards the bottom right corner of the chart. This illustrates that over the last couple of decades, access to clean cooking fuels greatly expanded in many countries simultaneously with a drop in deaths caused by indoor air pollution. Between 2001 and 2019, access to clean cooking fuels in China increased from 42% to 78% of the population. Over that same period, the share of deaths caused by indoor air pollution dropped from 11.7% to 3.3%.
1 Global Burden of Disease Collaborative Network. Global Burden of Disease Study 2019 (GBD 2019) Results. Institute for Health Metrics and Evaluation (IHME), 2021, https://vizhub.healthdata.org/gbd-results/; World health Organization, Household air pollution (Factsheet), 27 July 2022, Link