12:49pm Tuesday 28 January 2020

WHO sets benchmarks to reduce health damage from indoor air pollution

The new “WHO guidelines for indoor air quality: household fuel combustion” stress the need to improve access to cleaner home energy sources such as liquefied petroleum gas, biogas, natural gas and ethanol, or electricity, particularly in low- and middle-income countries.

These new guidelines come after WHO findings earlier this year revealed that more than 7 million people – one in eight of total global deaths – are due to indoor or outdoor air pollution exposure. According to the estimates, some 4.3 million people worldwide die every year from household air pollution emitted by rudimentary biomass and coal cookstoves.

“Ensuring cleaner air in and around the home is fundamental to reducing the burden of disease from air pollution, especially in low- and middle-income countries,” says Dr Maria Neira, WHO Director for Public Health, Environmental and Social Determinants of Health. “The new WHO guidelines aim to help countries introduce cleaner technologies, improve air quality in poor households, reduce pollution-related diseases and save lives.”

Nearly 3 billion people worldwide still lack access to clean fuels and technologies for cooking, heating and lighting. Millions of people die each year as a result of household air pollution; 34% are due to stroke, 26% to ischaemic heart disease, 22% to chronic obstructive pulmonary disease, 12% to childhood pneumonia and 6% to lung cancer.

These diseases are primarily caused by high levels of fine particulate matter and carbon monoxide released by the burning of solid fuels such as wood, coal, animal dung, crop waste and charcoal in inefficient stoves, space heaters, or lamps.

New emissions targets

The guidelines include emissions targets for different kinds of domestic appliances, for both carbon monoxide and fine particulate matter. The targets are the result of years of review of the health impacts of household air pollution emissions and careful examination of the levels by which emissions would have to be reduced in order to meet WHO guidelines for air quality.

“If the new emission targets are met, then some 90% of homes globally will meet WHO’s air quality standards,” said Dr Neira.

Avoid unprocessed coal and kerosene

The new guidelines recommend halting the use of unprocessed coal as a household fuel. Coal contains toxic elements such as arsenic, lead and mercury. The incomplete combustion of coal in inefficient stoves and space heaters can lead to severe illness and premature death.

The use of kerosene as a household fuel is also discouraged amid concerns around its adverse impact on air quality and safety. Kerosene is also associated with burns, fires and poisoning.

Health consequences

In homes with open-burning and unvented coal or biomass stoves, emissions of particulate matter and other pollutants can be 100 times higher than WHO-recommended levels. Such pollutants are carcinogenic and cause heart and lung disease through impairing immune response, reducing the oxygen-carrying capacity of the blood, causing systemic inflammation and ischemia, among other physiological disturbances.

“Women and young children, who spend the most time near the domestic hearth, are particularly vulnerable,” says Dr Flavia Bustreo, WHO Assistant Director General, Family, Women’s and Children’s Health cluster. “Globally, more than 50% of pneumonia deaths among children under 5 are linked to household air pollution.”

Women and children may also suffer other consequences. In many regions, they spend hours every day gathering fuel for traditional stoves, restricting time for earning money and going to school.

The way forward

In order to meet the new targets, there needs to be rapid scale-up in access to cleaner and more modern cooking and heating appliances, as well as lamps, in developing country homes, says Dr Carlos Dora, WHO Coordinator for Public Health, Environmental and Social Determinants of Health.

“We need to scale up the use of clean fuels such as biogas, ethanol, or natural or liquefied petroleum gas with appropriate venting, as well as solar electricity solutions for lighting,” he said. “And clean technologies and fuels should be priced within reach of the lowest-income households.”

At the same time, the new guidelines advise countries not to use unprocessed coal or kerosene as home energy sources, and to look for substitute fuels.

“A great deal of work is going into improving the types of biomass cookstoves commonly used in developing countries for preparing meals, but only those that achieve these household fuel combustion emission targets can ensure lower health risks from household air pollution for women and children.”

WHO regional and country offices will support governments, non-governmental organizations, the private sector and development partners in implementation of these guidelines. The guidelines will be reviewed and updated periodically.

Note for editors:


Emission targets


Fine particulate matter*


  • Appliances with chimneys or hoods: no more than 0.80 milligrams/minute (mg/min).
  • Unvented stoves, heaters and fuel-based lamps: no more than 0.23 mg/min.


Carbon monoxide


  • Appliances with hoods or chimneys: no more than 0.59 g/min.
  • Unvented stoves, heaters and fuel-based lamps; no more than 0.16 g/min.


*Fine particulate matter is a complex mixture of solid and liquid particles consisting mainly of sulfate, nitrates, ammonia, sodium chloride, black carbon, mineral dust and water.


These WHO guidelines were informed by a rigorous review of all currently available scientific knowledge and were peer-reviewed by scientists around the world.


Today the world also commemorates the sixth annual World Pneumonia Day by calling on global leaders to achieve universal access to pneumonia prevention and care and end preventable child deaths by the year 2030.


WHO media contacts


Christian Lindmeier
Communications Officer
Telephone: +41 22 791 1948
Mobile: +41 7 95 00 65 52
Email: lindmeierch@who.int


Nada Osseiran
Communications Officer
Department of Public Health, Environmental and Social Determinants of Health
Telephone: +41 22 791 4475
Mobile: +41 7 94 45 16 24
Email: osseirann@who.int

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