Indoor Air Pollution: Causes, Sources, Effects & Prevention/Solutions

There’s two main types of air pollution – indoor, and outdoor air pollution.

This guide focuses on indoor air pollution, and specifically in parts of the world where it causes the most harm – which is mostly lower income countries and regions.

We look at some causes, sources, examples, effects, and potential ways to prevent or solve it.


Summary – Indoor Air Pollution

Indoor air pollution happens inside dwellings and buildings (as opposed to the outside atmosphere)

Indoor air pollution might be more detrimental in developing countries where people don’t have access to safe electricity and energy production (natural gas or renewable energy, for example). People in developing regions might use solid fuels (like wood and organic matter) more frequently, as well as kerosene for cooking, cleaning, heating etc.

Particulates and other air contaminants can enter the air as a result of these activities, and especially in smoke

Small particulates like PM10 can be some of the most damaging/harmful air pollutants

Carbon monoxide and VOC’s can also be problematic

A range of health related diseases and illnesses can potentially occur as a result of this, as well as death

Young children and women are some of those most affected in developing regions and low income areas

Asia and Africa on a regional level, and China and India on a country level, are among the regions and countries with the highest concentration of deaths (and highest mortality rates) from indoor air pollution

Providing cleaner, more modern, and safer indoor systems for heating, cooling and cooking within dwellings might help significantly reduce indoor air pollutants

In developed countries, reducing the use of indoor and outdoor contaminants in products we use (or reducing the use of these products altogether), reducing second hand sources of air contaminants like smoking, and having good ventilation, can all help.

Encouragingly, deaths from indoor air pollution are on a steady decline. China is one example of a country that has seen a decline in the last decade

Although, some countries like the DRC (Congo) might not be experiencing a decline


What Is Indoor Air Pollution?

Indoor air pollution is a change in the Indoor Air Quality, usually by the introduction of an air contaminant, that has a harmful effect on any living thing that consumes that air


  • Indoor Air Quality ‘refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants’



There’s really two distinct types of indoor air pollution – indoor air pollution in developed countries, and indoor air pollution in poorer parts of the world.


Causes, Sources & Examples Of Indoor Air Pollution

In the two examples outlined below:

  • Developing Countries – comes mainly from lacking access to modern cooking and heating systems, and burning solid fuels and kerosene in the open, on open stoves and using inefficient cooking practices
  • Developed Countries – comes mainly from household and outdoor products, and second hand sources like smoking

In both cases, a lack of ventilation can compound the issue.


  • Indoor air pollution in poorer parts of the world is far more severe, and is usually caused by the inefficient use of solid fuels for cooking and cleaning [and heating]
  • There is smoke and other contaminants released from burning non modern energy sources inside the house like wood, crop residues, dung, charcoal, coal and kerosene.

– OurWorldInData. 


  • In 2018, around 3 billion people still cook using polluting open fires or simple stoves fuelled by these types of fuels
  • Small particulate matter in smoke is one of the main indoor air pollutants [Small particles of less than 10 microns in diameter (PM10), are among the most dangerous]



  • Indoor air pollution in developed countries is less severe (but can still causes short and long term health problems) and is caused by things like mold, household sprays (aerosols for example), cleaning chemicals, garden sprays (insecticides for example) and so on.
  • Particulate matter, carbon monoxide and VOC’s also come from things like second hand tobacco smoke, the use of space heaters and paints/coatings.

– Wikipedia


Effects Of Indoor Air Pollution

The effects of indoor air pollution can include health diseases, as well as death.

But, the trends worldwide are that deaths are decreasing in total over the last few decades.

Young children, and women, might be the ones mainly impacted.


Indoor air pollution can lead to:

  • … acute lower respiratory disease, chronic obstructive pulmonary disease, cancers, and other illnesses.



  • In total, 2.6 million people died prematurely in 2016 from illness attributable to household air pollution

– OurWorldInData/Institute for Health Metrics and Evaluation (IHME)


The World Health Organisation says ‘close to 4 million people die prematurely from illness attributable to household air pollution from inefficient cooking practices using polluting stoves paired with solid fuels and kerosene. Household air pollution causes noncommunicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer’

Deaths are attributable to the following diseases in the following %’s:

  • 27% are due to pneumonia
  • 18% from stroke
  • 27% from ischaemic heart disease
  • 20% from chronic obstructive pulmonary disease (COPD)
  • 8% from lung cancer.

– World Health Organization (WHO)


  • Close to half of deaths due to pneumonia among children under 5 years of age are caused by particulate matter (soot) inhaled from household air pollution



The trends with indoor air pollution is:

  • Overall, ‘we see a decline in the number of pollution-related deaths since 1990, falling from 3.7 million to 2.6 million in 2016.’
  • It is predominantly women and young children who are killed by indoor air pollution

– OurWorldInData


Countries & Regions Where Indoor Air Pollution Can Be An Issue

Indoor air pollution mortality rates impact certain regions and countries more than others.

Asia, Africa on a regional level, and on a country level, China and India have some of the highest %’s and totals.


  • Deaths from air pollution are ‘largely concentrated in Asia and Africa.
  • Approximately three-quarters of all deaths in 2016 were in Asia, with 22-23 percent in Africa & the Middle East, and only a couple of percent across the Americas and Europe (with most of these originating in Latin America & the Caribbean)’. 
  • At the country level – ‘India followed by China had the highest mortality figures in 2016 with 783,000 and 605,000 respectively. These numbers have, however, shown a significant decline in recent years. In the last decade alone the number of deaths from household air pollution in China has approximately halved.’ 
  • … This is however not true everywhere: the Democratic Republic of Congo appears to still be on the upward slope of this pattern.’

– OurWorldInData

You can read more about indoor air pollution related death rates, overall trends, and how different countries are affected here (


Indoor Air Pollution In Developed Countries

Indoor air pollution in developed countries tends not to be anywhere near as severe:

  • … it might only usually result in short term [less severe] side effects 
  • People most at risk might be people who may be exposed to indoor air pollutants for the longest periods of time such as the young, the elderly and the chronically ill, especially those suffering from respiratory or cardiovascular disease [and conditions like asthma]
  • In developed countries [individual sources of pollution aren’t a big risk, but the cumulative effect of all sources might be] 



Potential Solutions For Indoor Air Pollution/How To Prevent It

Two of the biggest solutions might be:

  • Developed Countries – be mindful of the contaminants being used in the house and outside. Be mindful of second hand sources like indoor smoking
  • Developing Countries (& Low Income Countries) – introduce cleaner and more modern heating and cooking systems for households, especially where women and children are using them, and in rural and low income areas

Better ventilation can also help.


  • In developing countries and poorer countries, the best way to prevent indoor air pollution and it’s harmful effects it is to switch to modern energy sources which don’t release smoke and other harmful indoor air contaminants.
  • This involves switching to non solid fuels for heating and cooking such as natural gas, ethanol or electric technologies.

– OurWorldInData


An example of where and how this might be occurring is with the AKON Lighting Africa Project, which is replacing solid fuels with clean and affordable electricity in the form of solar panels/solar energy.

Specifically, the following demographics may need more help with indoor air pollution prevention:

  • Low income countries and areas (that don’t have access to, or can’t afford cleaner energy)
  • Women and children
  • People in more isolated rural areas (vs more highly populated urban areas for example)

Improved design of stoves and ventilation systems can also reduce indoor air pollution in many poor communities, as well as raising more awareness about the issue to those most at risk



In developed countries, limiting the number of contaminants in or around your house, having proper ventilation, and keeping at risk people (those who spend a lot of time inside) in a part of the house with high air quality can help minimise the effects of indoor air pollution.




2. Max Roser and Hannah Ritchie (2018) – “Indoor Air Pollution”. Published online at Retrieved from: ‘’ [Online Resource]






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