Impacts of indoor air pollution

According to the World Health Organization “There is consistent evidence that exposure to indoor air pollution can lead to acute lower respiratory infections in children under five, and chronic obstructive pulmonary disease and lung cancer…… adults”

Types of Pollution

Indoor smoke contains a variety of health-damaging pollutants: This can be second hand tobacco smoke, cooking smoke, or smoke from combustion processes such as fireplaces. Particles (complex mixtures of chemicals in solid form and droplets) from industrial and automotive pollution can enter the home. Some other forms of pollution found in indoor environments include carbon monoxide, nitrous oxides, sulfur oxides (mainly from coal), formaldehyde, Radon and other carcinogens (chemical substances known to increase the risk of cancer) such as benzopyrene and benzene. Small particles with a diameter of 10 microns (PM10) or less are able to penetrate deep into the lungs and appear to have the greatest health-damaging potential.

Health effects

Acute lower respiratory infections

  • There is consistent evidence that exposure to…….smoke increases the risk of acute lower respiratory infections (ALRI) in childhood,

COPD (Chronic obstructive pulmonary disease)

  • Indoor air pollution is considered a risk factor for chronic bronchitis (CB) and chronic obstructive pulmonary disease (COPD . The association between exposure to…….smoke and CB/COPD is well established, especially for women.

Lung cancer

Smoke in most forms contains substantial amounts of carcinogens. The presence of carcinogens in smoke implies the risk of lung cancer may be present.

Other health outcomes

  • Low birth weight and perinatal mortality
  • Asthma
  • Otitis media and other acute upper respiratory infections
  • Nasopharyngeal cancer
  • Laryngeal cancer
  • Cataracts
  • Cardiovascular disease


The air we breathe can be contaminated by emissions from motor vehicles and commercial/industrial sources, as well as tobacco smoke and household combustion processes. In the WHO European Region alone, exposure to particulate matter (PM) decreases the life expectancy of every person by an average of almost 1 year, mostly due to increased risk of cardiovascular and respiratory diseases, and lung cancer. Furthermore , a recent study using data from 25 cities in the European Union has estimated that life expectancy could be increased by up to approximately 22 months in the most polluted cities if the long-term PM2.5 concentration was reduced to the WHO guideline annual level.

Data from the WHO Environment and Health Information System (ENHIS), covering 357 European cities in 33 countries, show that in 2009 almost 83% of the population in these cities was exposed to PM10 levels exceeding the WHO guidelines.

Some 40 million people in the 115 largest cities in the European Union (EU) are exposed to air exceeding WHO air quality guideline values for at least one pollutant. Children living near roads with heavy-duty vehicle traffic have twice the risk of respiratory problems as those living near less congested streets.

Indoor air pollution from biological agents in indoor air related to damp and mold increases the risk of respiratory disease in children and adults by 50%. Second-hand smoke causes severe respiratory health problems in children such as asthma and reduced lung function. It also causes lung disease, cardiovascular diseases, cancer and premature death in adults.

The WHO maintains that by reducing particulate matter pollution from 70 to 20 micrograms per cubic meter that air quality related deaths would be reduced by around 15%,

Indoor Air Quality

Poor indoor air quality can cause or contribute to the development of infections, lung cancer, and chronic lung diseases such as asthma. In addition, it can cause headaches, dry eyes, nasal congestion, nausea and fatigue. People who already have lung disease are at greater risk.
The American Lung Association recommends that the first line of defense against indoor air pollution is finding ways to keep the pollutants from being added to the air in the first place. This is known as source control. Appropriate ventilation with clean fresh air can also reduce levels of indoor air pollutants. Finally, while air cleaning devices can be useful, they are no substitute for preventing the air from getting dirty in the first place.
Some common air pollutant information set out by the American Lung Association is listed below.

Biological Pollutants

Includes molds, bacteria, viruses, pollen, animal dander and particles from dust mites and cockroaches. These may cause infections, provoke allergic symptoms or trigger asthma attacks. These may be a major cause of days lost from work and school. Means of control include washing bedding to kill dust mites, keeping animals out of areas affected persons frequent, and practicing careful cleaning. It is also critical to control moisture that promotes mold growth.

Secondhand Tobacco Smoke

Secondhand Smoke is a major indoor air pollutant. It contains some 200 known poisons, such as formaldehyde and carbon monoxide, and at least 60 chemicals known to cause cancer. In U.S. nonsmokers, every year it causes an estimated 3,000 lung cancer deaths and up to 50,000 heart disease deaths. In children, especially infants, it is responsible for pneumonia, lower respiratory tract infections and ear infections. It causes asthma to develop, causes asthma attacks, and makes attacks worse. Source control is basic: No one should smoke around children.

Combustion Pollutants

Combustion Pollutants come from sources such as fuel burning stoves, furnaces, fireplaces, heaters, and water heaters, using gas, oil, coal, wood, or other fuel. The most dangerous are both colorless and odorless gases carbon monoxide (CO) and nitrogen dioxide (NO2). CO interferes with the delivery of oxygen to the body. It can produce fatigue, headache, confusion, nausea, and dizziness. Very high levels can cause death. NO2 irritates the mucous membranes in the eye, nose and throat and can cause shortness of breath and promote infections. The best way to control these pollutants is to make sure combustion appliances are installed and maintained by reliable professionals, and properly used. A UL-listed CO monitor should also be installed.


Radon, a naturally occurring radioactive gas, can enter the home through cracks in the foundation floor and walls, drains, and other openings. Indoor radon exposure is estimated to be the second leading cause of lung cancer in the U.S., responsible for at least 21,000 lung cancer deaths each year. Steps to control radon include testing ones home, and following recommendations for further testing and repairs. There is additional information on Radon elsewhere in this website.


A non-flammable mineral that can produce microscopic fibers, that when inhaled into the lungs can cause asbestosis (scarring of the lung tissue), lung cancer and another cancer called mesothelioma. Many asbestos products are found in the home, including roofing and flooring materials, and insulation for ceilings, walls, pipes and heating equipment. To avoid asbestos exposure, either cover intact source materials with an airtight seal or use professional services to remove damaged source materials.


A common chemical, found primarily in adhesive or bonding agents for many materials found in households and offices, including carpets, upholstery, particle board, and plywood paneling. The release of formaldehyde into the air may cause health problems, such as coughing; eye, nose, and throat irritation; skin rashes, headaches, and dizziness. The best control is to avoid using products that emit formaldehyde. Though not as effective, try to be sure that new potential sources are sufficiently aired out before bringing them indoors.
Hundreds of potentially harmful chemicals are emitted by household cleaning agents, personal care products, pesticides, paints, hobby products, and solvents. Such chemicals can cause dizziness, nausea, allergic reactions, eye/skin/respiratory tract irritation, and cancer. Minimize your use of such sources of dangerous chemicals, and be sure to follow manufacturers directions, including using protective equipment and adequate ventilation. An alternative is to find safer substitutes.

Why does Indoor Air Quality matter?

The air quality of our indoor environments affects our health and often contributes to structural degradation and building failures within our homes. Consider the Facts. According to the American Lung Association of Minnesota, elements within our home and workplaces have been increasingly recognized as threats to our respiratory health. The most common pollutants are radon, combustion products, biological agents (molds, pet dander, pollen), volatile organic compounds, lead dust and asbestos.The Environmental Protection Agency lists poor indoor air quality as the fourth largest environmental threat to our country.

There are an estimated 40 million individuals in the United States who are affected by allergies. Learning how to control a homes environment to reduce allergen levels is important for managing allergies and asthma. Individuals who suffer from asthma, or have other respiratory illness may potentially be at a greater risk for health complications associated with poor air quality in their homes.The prevalence rate of pediatric asthma has increased from 40.1 to 69.1,—a 72.3 percent increase. Asthma is the sixth ranking chronic condition in our nation and the leading serious chronic illness of children in the U.S.
COPD, also known as emphysema and chronic bronchitis, is the third leading cause of death in the United States. The good news is that COPD is often preventable and treatable.

1. The author acknowledges that the primary sources for information on this page are from the World Health Organization and the American Lung association.