Air pollution is a big problem, from the spewing smokestacks and grey-brown skies of cities like Beijing and Delhi to the hormone-disrupting phthalates that off-gas from furniture and carpets inside new homes. But there is another type of air pollution that kills four million people a year, according to the World Health Organization, and that is the pollution caused by cooking indoors over open fires.
The WHO estimates that 7 million people die prematurely each year due to inhaling unhealthy airborne particles, which makes indoor cooking fires the biggest culprit for these deaths. It’s hard for many North Americans to imagine cooking over an open fire, since that’s not typically done here anymore, but it continues to be a part of daily life in many developing countries where dung, coal, wood, and crop waste are used as fuel instead of gas.
Kirk Smith, a professor at the University of California at Berkeley, describes having an indoor cooking fire as being equivalent to burning 400 cigarettes an hour. According to an article in Quartz:
“The smoke from these fires pumps a harmful fug of fine particles and carbon monoxide into homes. Lousy ventilation then prevents that smoke from escaping, sending fine particle levels soaring 100 times higher than the limits that the WHO considers acceptable.”
There are interesting reasons, though, why the cleaner alternatives to indoor cooking fires don't always catch on in developing countries. Take, for example, the Yucatan peninsula of Mexico, where indigenous Mayans continue to use indoor cooking fires situated inside three powerfully symbolic stones. It was found that improving ventilation meant that the palm-thatched roofs on houses didn't last as long. It turns out that the smoke keeps out bugs and insects that cause damage to the thatch, allowing it to last for 20 to 30 years. When ventilation improves and/or indoor cooking fires are eliminated, bugs proliferate and thatch lasts for only 10 years.
The Mayans are reluctant to get rid of their three stones, too, because they represent the traditional role of women in the home. Infant girls move from a swaddled position to straddling their mothers' hips with open legs as soon as they turn three months of age. This is directly related to the three stones, and is meant to prepare them for their future life spent working over the cooking fire and its stones. Infant boys, by contrast, have their legs opened at four months old in honour of the four corners of the corn fields where maize is grown for the tortillas that are served at every meal.
No doubt other cultures have similar beliefs and justifiable reasons for sticking with traditional cooking fires, which adds to the complexity of this issue. Something does have to change, however, especially since smoky cooking fires put children at great risk, since they spend so much time with their mothers who do most of the cooking. The WHO reports that indoor cooking smoke is responsible for more than half the deaths among children less than 5 years old from respiratory infections. With a total of 11,000 people dying daily from cooking smoke, it’s a problem that certainly deserves more attention.