Indoor air pollution is one of the great untold stories. It is responsible for more than a million premature deaths every year.

INTRODUCTION
The World Health Organization says 2.4 million people die each year from causes directly attributable to air pollution, with 1.5 million of these deaths due to indoor air pollution.

Indoor smoke is one of the world’s biggest contributors to ill health and premature death, with women and children in rural areas of developing nations at greatest risk.

When people burn wood, animal dung, crop waste or coal for cooking and heating this creates a lot of indoor smoke that is laden with pollutants such as carbon monoxide, benzene, nitrous and sulphur oxides, formaldehyde and harmful particles.

These pollutants are known to increase the risk of acute lower respiratory infections (the biggest killer of children under five), lung cancer and chronic obstructive pulmonary disease.

In urban areas, a long list of other pollutants can also threaten human health inside homes, workplaces and public buildings.

The more dangerous of these pollutants include: asbestos from insulating and other building materials; formaldehyde gas from carpets and wood; radon; vapours from paints, plastics and cleaning products; and cigarette smoke.

Biological sources of indoor air pollution include fungal spores, pollen and bacteria. People and their pets also contribute to the problem, by shedding flakes of skin, hair, etc.

Dust mites that live in carpets and bedding produce tiny pellets of faecal matter. Even houseplants, which can help to improve air quality, can cause problems by producing pollen, mould and dust.

Indoor air pollution in urban areas has been linked to health problems that include lethargy, headaches, dizziness, eye irritation and allergies, as well as more serious complaints including respiratory and cardiovascular diseases and cancer.

The term ‘sick building syndrome’ has been used to describe the situation when a large number of people who live or work in the same building report various symptoms.

ALTERNATIVES / SOLUTIONS
Indoor smoke can best tackled by replacing biomass fuels with gaseous fuels like kerosene, butane and propane, and by using more efficient stoves.

Good ventilation is also important for reducing health threats from indoor smoke and from other kinds of air pollution in both rural and urban settings.

Some countries have building regulations that includes standards for ventilation, and controls on the use of substances such as asbestos and formaldehyde in houses and workplaces.

Many countries are also moving to limit people’s exposure to cigarette smoke by banning smoking in workplaces.

REPORTING TIPS
For story ideas, journalists can visit the Indoor Air Pollution Updates blog, which tracks news about this issue.

Reporting on indoor air pollution linked to household stoves is relatively straightforward as there is strong scientific evidence for how indoor fires can harm health and for what safer alternatives are.

There are bigger challenges for journalists reporting on health problems linked to other kinds of indoor air pollution, as there is a such a wide range of possible threats.

If an individual chemical (e.g. asbestos or leaded paint) is suspected to be causing health problems, journalists will need to see if there are other possible causes and seek scientific opinions about what is most likely to be to blame.

If local health authorities have been alerted to the problem they may be conducting investigations that include assessments of air quality that journalists can report on.

Journalists should interview a large number of people to assess whether the symptoms are widespread among people who use the same building – and check whether the problem has occurred before.

Another line of inquiry is to check whether buildings and materials comply with the relevant health and safety regulations.

Reporters should also be aware of the relationship between indoor air pollution and climate change.

Black soot in smoke from fires helps to trap heat in our atmosphere and about one-third of this soot comes from households burning fuel.

The cheapest solution to indoor smoke is to promote use of fossil fuels such as butane, whose combustion releases greenhouse gases that also contribute to climate change.

This is however a much faster and cheaper solution that waiting for widespread access to electricity from renewable sources such as wind or solar power.

CASE STUDY – Formaldehyde in California and woodsmoke in Kenya
A 2009 report showed that two-thirds of single-family homes built in California in recent years had excessive levels of formaldehyde, a chemical present in many building materials and household products.

Formaldehyde is linked to both acute health problems such as sore throats and more serious diseases including cancer.

The study found that the reason for this was that residents rarely opened their windows for ventilation because they were concerned about safety, noise and dust.

In rural areas of developing countries, the major source of indoor air pollution comes from fires for cooking.

In Kenya, for instance, the nongovernmental organisation Practical Action found that smoke levels inside some homes were 100 times higher than international safety standards.

Practical Action worked with women there to develop a simple smoke hood, which has reduced smoke levels in their houses by up to 80 percent.

For more case studies see the Toolkit pages on asbestos, benzeneand radon.

LINKS TO OTHER TOOLKIT PAGES
Air Pollution (Outdoor)
Asbestos

FURTHER READING
World Bank – Indoor Air Pollution
World Health Organization – Indoor Air Pollution
Partnership for Clean Indoor Air
Smoke — the Killer in the Kitchen (Report by Practical Action).