4 major Sources of Indoor Air Pollution and their Effects

4 Major Sources of Indoor Air Pollution and their Effects

Our general health and well-being depend on maintaining adequate indoor air quality. Unfortunately, the air in our homes and places of employment can include a variety of contaminants that can harm our respiratory systems, set off allergies, and even cause long-term health problems. The four main sources of indoor air pollution and their impacts on human health will be discussed in this article.

What is indoor pollution and how does it affect human health? 

What is indoor pollution and how does it affect human health? 

When dangerous pollutants and toxins are present in the air of structures like houses, offices, schools, and other enclosed spaces, it is referred to as indoor pollution. These pollutants may originate from a number of things, such as biological agents, building materials, household goods, and combustion activities. The consequences of indoor pollution on human health can be detrimental over time.

Indoor pollution can irritate and swell the respiratory system, which can cause a variety of respiratory issues. Asthma, bronchitis, and chronic obstructive pulmonary disease (COPD) can be brought on by or made worse by inhaling fine particulate matter (PM2.5), which is released through sources like cooking, smoking, or inadequately ventilated areas. The risk of respiratory illnesses can also be raised by pollutants like nitrogen dioxide (NO2), which is present in gas heaters and stoves.

Dust mites, mould spores, pet dander, and pollen are among indoor pollutants that can cause allergic reactions and asthma episodes. When disturbed, the allergens that collect in carpets, beds, and upholstery become airborne and can be inhaled. Sneezing, coughing, wheezing, and shortness of breath are some of the symptoms that people who already have allergies or asthma may experience when they are exposed to these triggers.

Chemical Sensitivities: Some people may develop chemical sensitivities as a result of the volatile organic compounds (VOCs) released by household goods, paints, solvents, and furnishings. Headaches, nausea, dizziness, exhaustion, and skin irritations are just a few of the symptoms that can result from these sensitivities. Formaldehyde is one VOC that has been connected to more serious health impacts, such as harm to the liver, kidneys, and central nervous system. Long-term exposure to some VOCs may potentially make cancer more likely.

Cardiovascular Problems: Indoor air pollution can harm the cardiovascular system. Through inhalation, fine particulate particles and various gases, including carbon monoxide (CO), can enter the bloodstream and possibly cause cardiovascular issues. An increased risk of heart attacks, strokes, high blood pressure, and other cardiovascular disorders has been linked to prolonged exposure to these pollutants.

Impacts on Mental Health: While research on the precise connection between indoor pollution and mental health is ongoing, there is evidence that shows that poor indoor air quality can have detrimental impacts on mental health. Long-term exposure to pollutants may be a factor in the development of symptoms like exhaustion, trouble focusing, irritability, and elevated stress levels. These elements may have an effect on cognitive ability and general mental health.

4 Major Sources of Indoor Air Pollution

4 Major Sources of Indoor Air Pollution

Combustion Sources

Combustion sources refer to devices, systems, or processes that involve the burning or combustion of fuels to generate heat, light, or power. Combustion is a chemical reaction that occurs when a fuel combines with oxygen in the presence of heat, resulting in the release of energy in the form of heat, light, and various combustion byproducts.

Combustion sources include:

  • gas stoves
  • fireplaces
  • tobacco smoke
  • heating systems that use fossil fuels

Carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) are only a few of the toxic gases and particles released by these sources. Long-term exposure to these pollutants can worsen asthma symptoms, cause respiratory issues, and raise the risk of cardiovascular disorders. In particular, carbon monoxide is an odorless, colorless gas that, in high amounts, can be lethal.

Volatile Organic Compounds (VOCs)

Cleaning supplies, paints, solvents, and furniture are just a few examples of household items that release volatile organic compounds as gases. 

Common VOCs include:

  • formaldehyde
  • benzene
  • toluene
  • xylene

Long-term health impacts like liver, kidney, or central nervous system damage can occur as a result of prolonged exposure to VOCs, along with headaches, dizziness, and irritation of the eyes, nose, and throat. Some VOCs, such as formaldehyde, are also categorized as carcinogens and may raise the chance of developing cancer.

Biological Contaminants

Biological contaminants are living organisms or their byproducts found indoors, including:

  • mould
  • bacteria
  • viruses
  • pollen
  • pet dander

In humid environments, with poorly maintained ventilation systems, especially in moist locations, these pollutants can flourish. These toxins can cause allergic reactions, respiratory infections, asthma attacks, and other respiratory issues when inhaled or come into touch with them. Particularly mould can disperse spores into the air, triggering allergic responses and respiratory problems.

Indoor Particulate Matter

Indoor Particulate Matter

Indoor particulate matter includes a range of tiny particles suspended in the air, such as:

  • dust
  • pollen
  • pet dander
  • smoke particles

These particles may originate outside or may be produced indoors by tasks like cooking, cleaning, and candle burning. Fine particulate matter (PM2.5) inhalation can cause respiratory and cardiovascular issues by penetrating deeply into the lungs and possibly into the circulation. Additionally, it may exacerbate pre-existing respiratory illnesses including asthma or chronic obstructive pulmonary disease (COPD).

How to improve the quality of indoor air?

How to improve the quality of indoor air?

To maintain a healthy living or working environment, indoor air quality must be improved. Here are some practical steps you may take to enhance the quality of the air within your home:

  • Proper Ventilation: When the weather permits, open windows, and doors to let fresh air circulate.
  • Utilise exhaust fans in the kitchen and bathroom to get rid of moisture and contaminants.
  • Install ventilation systems and keep them up-to-date to ensure appropriate airflow throughout the facility.
  • Avoid smoking indoors to reduce and eliminate indoor pollution. A substantial contributor to indoor air pollution is cigarette smoke.
  • For best results, maintain indoor humidity levels between 30% and 50%. Utilise dehumidifiers if required.
  • Choosing low- or no-VOC building materials, paints, varnishes, adhesives, and furniture will help you reduce your exposure to VOCs.
  • Change HVAC filters frequently to prevent the accumulation of dust and other particles. Regular maintenance of HVAC systems.
  • Mould prevention and moisture management. Any plumbing leaks must be repaired right away.
  • Make sure there is adequate ventilation in damp places like basements, bathrooms, and kitchens.
  • Within 24 to 48 hours of water damage, clean and dry the affected areas to stop the growth of mould.
  • Increase Natural Ventilation: Add plants to indoor spaces to assist filter the air and enhance the quality of the air.
  • Test and Monitor Home Air Quality: To gauge and track the quantities of contaminants in your home environment, think about employing air quality sensors.

You may greatly enhance indoor air quality and create a healthier living or working environment for you and others by putting these strategies into practice.


Our health and well-being can be significantly impacted by indoor air pollution. We can take the required steps to improve indoor air quality by being aware of the main sources of indoor air pollution and their impacts. The number of contaminants in the air we breathe can be significantly reduced by implementing effective ventilation, utilizing low VOC products, frequently cleaning and maintaining living areas, and forming healthy behaviors like quitting smoking inside. We can build healthier settings and protect our respiratory health in the long run by putting a priority on clean indoor air.


  1. Indoor Air Pollution, Related Human Diseases, and Recent Trends in the Control and Improvement of Indoor Air Quality: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7215772/
  2. Source-specific exposure and risk assessment for indoor aerosols: https://pubmed.ncbi.nlm.nih.gov/30851679/
  3. Particulate matter air pollution components and risk for lung cancer: https://pubmed.ncbi.nlm.nih.gov/26641521/