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

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

When it comes to air pollution, there are two main types – 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 the poorer/lower income countries and regions.

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


Summary – What To Know About Indoor Air Pollution

It’s goes without saying that indoor air pollution happens inside dwellings and buildings, and not out in the atmosphere.

Much of the most harmful indoor air pollution happens in developing countries where people don’t have access to safe electricity and energy production (natural gas or renewable energy, for example).

People use solid fuels (like wood and organic matter) for cooking, cleaning, heating etc.

A range of health related diseases and illnesses can occur as a result of particulates and other air contaminants that enter the air.

Providing cleaner, safer energy to people to use within dwellings and their houses could go a long way towards helping with the issue of indoor air pollution.


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

  • 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

Indoor air pollution can lead:

  • … 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 Where Indoor Air Pollution Can Be An Issue

  • 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 decline is ‘also true for countries in Sub-Saharan Africa (SSA) with high mortality figures. Ethiopia and Nigeria – who have the two highest death tolls in SSA – have both seen a inverse-U trend of increase-peak-decline since 1990. 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 –, and 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 side effects such as irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. But, some more severe cases can also cause long term health 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. People with breathing conditions like asthma also
  • In developed countries, ‘while pollutant levels from individual sources may not pose a significant health risk by themselves, most homes have more than one source that contributes to indoor air pollution. There can be a serious risk from the cumulative effects of these sources.’



Potential Solutions For Indoor Air Pollution/How To Prevent It

  • 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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