Indoor air pollution kills between 3.5 million and 4.3 million people worldwide each year. This terrible health crisis is however passed over in silence and many people do not even suspect its existence. We are lifting the veil on this serious problem which is one of the most deadly in the world.

Every year, indoor air pollution hits 3.5 million to 4.3 million people

This figure is alarming, especially when one realizes that it must be distinguished from deaths caused by “external” pollution and that it kills 3 million people a year. Also note that indoor air pollution kills many more people than AIDS and malaria combined: together, these diseases are responsible for about 2.2 million deaths in the world each year. However, this serious problem is considered by very few countries as a major health crisis, especially because it does not affect rich countries.

It should be noted that around the world, 3 million people (most on the African continent and Asian) do not have access to modern energy and continue to cook and heat their homes by burning coal, manure, charcoal and wood indoors. Often, these same homes do not have aeration system and are thus plunged into a cloud of smoke that can cause a slew of serious respiratory diseases, including lung cancer and chronic cardiovascular disease.


In China, 10 million households continue to burn coal directly inside their homes for cooking and heating. In India and Africa, wood and charcoal are more commonly used. And in other countries, such as Kenya or Ethiopia, where wood is scarce, animal dung is most often used. All these fuels lead to different health problems that are all equally dangerous.

Lighting is also a major source of indoor air pollution, particularly because of the use of oil lamps. Note, however, that LED lighting is becoming more and more common and as it becomes more democratic across “poor” countries, this aspect of the problem is reduced somewhat, even if it is still current, very worrying.

Finally, most homes (which are mostly built with mud or thatch) do not have adequate ventilation systems. Moreover, in countries where climatic conditions are “extreme”, they are not used when they have the merit of existing, in order to save energy. This results in extremely toxic amounts of polluted air, especially when many people in Africa have a habit of bringing a simple stove in the room where they sleep to keep the place at a good temperature during the night.

In theory, this problem should be easy to “manage”: it would be enough to offer all these people access to cleaner fuels and cooks … But in practice, it is not so simple. As revealed in a United Nations Environment Program (UNEP) pollution report, even countries most committed to promoting cleaner fuels (such as propane or butane) have often struggled to convince their inhabitants to change their fuel efficiency. habits. The same goes for the use of heating systems and stoves with better ventilation.

Main facts

About 3 billion people cook and heat their homes using open fireplaces or simple stoves in which they burn biomass (wood, animal dung, agricultural residues) and coal.

More than 4 million people die prematurely from diseases caused by household air pollution from cooking with solid fuels

More than half of pneumonia deaths in children under 5 are due to inhalation of particulate matter from indoor air pollution.

There are 3.8 million premature deaths from noncommunicable diseases, including strokes, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer, from exposure to air pollutants. interior of dwellings.


In the Caribbean, Central America and South America in particular, governments have tried to expand access to cleaner fuels, but indoor air pollution has remained stubbornly high. The reason was that many people were still burning wood at home, because this option proved to be cheaper and, according to them, more “reliable”, as reported by UNEP.

A “experience” dating back to 2012, conducted in India, perfectly illustrates the reluctance of some people to engage in new systems and new fuels less polluting … Several households, randomly selected, received stoves with fireplaces that drove smoke out of their homes. After one year of use, the smoke inhalation rate had decreased somewhat. However, 4 years later, no noticeable difference could be noted. Why ? Well, because these same households had simply stopped using these stoves since they required too much repairs and the chimneys required constant maintenance.

An Asian girl preparing to eat via Shutterstock

Health effects

Each year, 4.3 million people die prematurely from indoor air pollution, which results from inefficient use of solid fuels (based on 2012 data) for cooking. The distribution of these deaths by cause is as follows:

  • 34% cerebrovascular accidents
  • 26% ischemic heart disease;
  • 22% chronic obstructive pulmonary disease (COPD),
  • 12% pneumonia; and
  • 6% lung cancer.

Nearly a quarter of all premature deaths from stroke (about 1.4 million, half of which are women) can be attributed to chronic exposure to pollutants released into the indoor air during cooking. foods using solid fuels.

Ischemic heart disease

It is estimated that about 15% of all deaths from ischemic heart disease, more than one million premature deaths a year, result from exposure to polluted indoor air.

Chronic obstructive pulmonary disease

More than one-third of adult chronic obstructive pulmonary disease (COPD) deaths in adults in low- and middle-income countries result from exposure to indoor air pollution. Women exposed to high levels of domestic smoke are twice as likely to have COPD as those who use cleaner fuels. Exposure to domestic smoke almost doubles this risk (factor 1.9) in men, already at increased risk of COPD because of their higher smoking rate.


Exposure to indoor air pollution almost doubles the risk of pneumonia in children. More than half of the deaths of children under five years of age as a result of acute lower respiratory infections are due to the inhalation of particulate matter from solid domestic fuels (WHO, 2014).

Lung cancer

About 17% of premature deaths from lung cancer result, in adults, from exposure to carcinogens in domestic air because of its pollution by cooking food with solid fuels such as wood, charcoal and charcoal. Women are at increased risk because of their role in food preparation.

Other health effects

More generally, fine particulate matter and other pollutants in household fumes cause inflammation of the airways and lungs, which degrades the immune response and reduces the oxyphoric power of the blood.

Some data prove the links between indoor air pollution and low birth weight, tuberculosis, cataracts and nasopharyngeal and laryngeal cancers.

Nevertheless, some good news confirms that all hope is not lost yet. According to the UNEP report, 97 out of 193 countries increased their proportion of households with access to cleaner cooking and heating systems between 2008 and 2013. For example, Costa Rica subsidized liquefied petroleum many families. Chile, meanwhile, has launched a program allowing people to exchange their old stoves for cleaner models. It only remains to hope that the remaining 96 countries follow the same path …

Daniel J. Rao / viaShutterstock

Too little known, indoor air pollution is a huge global health problem that requires us to focus on finding solutions as quickly as possible … Millions of lives are at stake ! Moreover, “outside” pollution is also extremely deadly since it kills more than 3 million people worldwide each year.