Indoor air pollution may kill 4 million a year
Such pollution dramatically increases the risk of both children and adults contracting chronic obstructive pulmonary disease (COPD), says the paper, published online last month in Seminars in Respiratory and Critical Care Medicine.
The conclusions are based on an analysis of medical studies about the respiratory effects on people exposed to household air pollution.
Around three billion people cook and heat their homes using unprocessed solid fuels such as wood, animal dung and crop waste, the study says. These are normally burned in open fires or simple stoves in rooms or huts with insufficient ventilation.
As a result, people breathe in high levels of pollutants, the researchers say, including particles of soot small enough to penetrate deep into the lungs, which is especially dangerous to children.
“A low lung function value at an early age seems to be a risk factor for developing chronic obstructive pulmonary disease later in life,” says Akshay Sood, a medical researcher at the University of New Mexico, United States, and one of the article’s authors. “This may explain the occurrence of indoor air pollution-related COPD in younger adults as compared to tobacco smoke-related COPD, which usually occurs at an older age.”
High levels of pollution from cooking and heating were associated with two major forms of COPD: chronic bronchitis and emphysema. But exposure to indoor pollution might also make people more susceptible to another form of obstructive airway disease called bronchial anthracofibrosis, the researchers concluded.
Young children and non-smoking women from parts of Africa, Asia and the Middle East are the most likely to contract this disease, the study found. That is because they spend more time at home than men, meaning they inhale more indoor air pollution produced by unventilated and inefficient stoves.
Apart from causing pain and fever, COPDs limit lung growth in children, which can result in chronic health problems such as shortage of breath and tiredness.
Health problems can be avoided by using clean fuels such as liquid propane, natural gas or electricity, the study suggests. But Sood says such fuels may be unavailable or affordable to many low-income people.
Rodolfo de Paula Vieira, who researches lung disease at the University of Nove de Julho in Brazil, says the study shows the need for public policies to ensure people can afford better stoves.
Improving wood-burning stoves, particularly their exhaust systems, would lower the concentration of harmful particles inside homes and stop people from developing lung disease, he says.