Indoor air pollution from burning fuels such as wood to heat or light homes or cook is putting nearly three billion people worldwide at risk of ill health and early death, new research suggests.

Cook wood stove

A woman uses firewood to cook in western Nepal. Women and children are particularly susceptible to the toxic effects of household air pollution and are exposed to the highest concentrations. (Navesh Chitrakar/Reuters)

It’s estimated that a third of the world’s population uses plant-based fuels such as wood or charcoal, often in an open fire or simple stove that can release many tiny particles that can get deep into the lungs, causing irritation.

In Tuesday’s Lancet Respiratory Medicine Commission, researchers examined the evidence on the effects of those kinds of household air pollution.

Professors Stephen Gordon from the Liverpool School of Tropical Medicine in the U.K. and William Martin from Ohio State University and their team conclude that an estimated 600 million to 800 million families worldwide are at increased risk of illnesses such as respiratory tract infections, pneumonia, chronic obstructive pulmonary disorder asthma and lung cancer.

"Women and children are particularly susceptible to the toxic effects of pollution and are exposed to the highest concentrations. Interventions should target these high-risk groups and be sufficient quality to make the air clean," the authors conclude.

Clean cooking technologies, such as advanced cook stoves and solar powered systems, exist. But they need to be affordable, efficient and long lasting to replace traditional methods, Gordon said in a journal release.

Martin said one of the biggest obstacles to changing cooking methods is cultural.

"In every culture, cooking is nurturing. It's there to grow and help children get strong, so I think that's part of the barrier we have to overcome in communicating this risk." 

Estimates suggest that household air pollution killed up to four million people in 2010. While overall rates of exposure have been declining slowly, population growth means the number of people exposed has been steady at around 2.8 billion people worldwide, the researchers said.

Pollution-related illness often develops gradually and can take years to manifest, Martin acknowledged.

In a journal comment on the series, Lancet editors said they hope the content "will provide the impetus to drive change and tackle what is a preventable, but devastating, burden on the health of the world’s population, not least in terms of the morbidity and mortality associated with acute and chronic respiratory diseases."

With files from CBC's Vik Adhopia