Traditional three stone fires are not able to fully burn fuel, causing toxic gas and other waste products to be emitted as a byproduct.
This is known as incomplete combustion, and the gases that result include: carbon monoxide, nitrogen dioxide, formaldehyde, acrolein, benzene, methane and methanol. These small particle pollutants penetrate deep into the lungs, causing permanent damage.
Many exposed to these fumes contract chronic obstructive pulmonary disease (COPD), which damages the lungs and makes breathing increasingly difficult. COPD can take the form of emphysema, chronic bronchitis, or both. Others exposed to indoor air pollution may suffer from such serious health complications as pneumonia, lung cancer, cataracts, tuberculosis, and heart disease. According to the World Health Organization, indoor air pollution is responsible for nearly half of the 1.2 million annual pneumonia fatalities of children under five.
A worldwide study demonstrated that in homes with open fire cookstoves, the average concentration of such small particle pollutants can exceed 200 times the World Health Organization's (WHO) recommended maximum daily average.
Through dangerous indoor air pollution, open fire cookstoves claim the lives of approximately 4.3 million people each year. Among the leading causes of death globally, this ranks higher than the number of annual deaths due to malaria, HIV/AIDS, or tuberculosis.
People in developing and newly industrialized countries are most impacted by this issue. According to the National Institute of Health, indoor air pollution is the only health risk factor that almost exclusively impacts the world’s poorest communities.