Air Pollution: Invading Your Home And Health

Air pollution is not just an outdoor concern. The air inside your home can be polluted, too, and often is. Indoor air pollution has the same negative effects as environmental pollution and can cause or worsen lung diseases. Indoor air pollution is generated by the use of inefficient and polluting fuels and technologies in and around the home. Common residential indoor pollutants include excessive moisture, volatile organic compounds (VOCs), combustion products, radon, pesticides, dust particles, viruses, and bacteria. Outdoor air enters and leaves a house by infiltration, natural ventilation, and mechanical ventilation.

Outdoor pollution can enter homes through doors, windows, pets, clothing, and more

Outdoor air pollution can enter homes through a variety of pathways, including open doors and windows, ventilation systems, and even through cracks in the building's foundation. This process, known as infiltration, occurs when outdoor air flows into the house through openings such as doors and windows, driven by air temperature differences and wind. Additionally, pollutants can be inadvertently brought indoors on shoes, clothing, and pets, as well as through the use of certain household products.

One of the main entry points for outdoor air pollution is through open doors and windows. This is a form of natural ventilation, where air moves freely between the outdoors and the inside of a building. While this can help improve indoor air quality by diluting indoor pollutants, it can also allow outdoor pollutants to enter. For example, harmful smoke from chimneys or pollutants from neighbouring homes can enter through open windows, affecting the indoor air quality.

Another way outdoor pollution enters homes is through mechanical ventilation systems. These systems are designed to remove stale indoor air and replace it with filtered outdoor air. However, if the filters are not properly maintained or replaced, they can become less effective at removing pollutants from the incoming air. Additionally, ventilation systems that are not regularly cleaned can circulate indoor pollutants throughout the house, contributing to poor indoor air quality.

Pollutants can also enter homes through less obvious pathways. Cracks or gaps in the building's foundation, for example, can allow radon, a naturally occurring radioactive gas, to enter. This is particularly common in areas with contaminated groundwater or soils. Additionally, volatile chemicals from outdoor sources can enter homes through the use of contaminated water supplies, such as during showering or cooking.

Finally, outdoor pollutants can be tracked into homes on shoes, clothing, and even pets. This is especially true for soils and dust particles that adhere to these surfaces and are then brought indoors. Pollutants from outdoor sources, such as lead-contaminated soil, can be inadvertently brought into the home in this manner. Therefore, it is important to consider not only the building itself but also the potential pathways that pollutants can take to enter the indoor environment.

Tobacco smoke is a major indoor air pollutant, with serious health consequences

Air pollution can enter homes through open doors and windows, on clothing, shoes, and pets, and even through foundation cracks. Indoor air pollution can be caused by sources inside the home, such as combustion sources, building materials, and furnishings. Tobacco smoke is a significant indoor air pollutant, with severe health consequences.

Tobacco smoke contains thousands of compounds, many of which are toxic and carcinogenic. These toxic substances can be found in secondhand smoke, which fills enclosed spaces when people smoke tobacco products. There is no safe level of exposure to secondhand smoke, and even brief exposure can cause immediate harm to adults and infants. The adverse effects of secondhand smoke include coronary heart disease, stroke, lung cancer, and adverse reproductive health effects in women, such as low birth weight. Infants exposed to secondhand smoke are also at an increased risk of sudden infant death syndrome (SIDS).

The Surgeon General's report in 1986 concluded that separating smokers and non-smokers within the same house may reduce non-smokers' exposure to environmental tobacco smoke but would not eliminate it. Ventilation can help reduce exposure to indoor air pollutants, but natural or mechanical ventilation techniques are often insufficient to remove tobacco smoke pollutants from the air quickly enough.

The economic costs of tobacco use are substantial, including healthcare costs for treating tobacco-related diseases and lost human capital due to tobacco-attributable morbidity and mortality. Tobacco kills more than 8 million people annually, including 1.3 million non-smokers exposed to secondhand smoke. Therefore, addressing the tobacco epidemic is crucial to reducing its health and economic impacts.

Household chores like cooking and collecting firewood expose women and children to harmful fuels

Air pollution can definitely get inside your house, and it can be extremely harmful. Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by failing to carry indoor air pollutants out of the home.

In 2020, an estimated 3.2 million deaths per year were attributed to household air pollution, with over 237,000 of those deaths being children under the age of five. The ingestion of kerosene by accident is the leading cause of childhood poisonings, and a large fraction of the severe burns and injuries occurring in low- and middle-income countries are linked to household energy use for cooking, heating, and lighting. Women are also more than twice as likely to suffer from chronic obstructive pulmonary disease than women who use cleaner fuels and technologies.

The use of polluting fuels and technologies in the home, such as open fires or inefficient stoves fuelled by kerosene, biomass (wood, animal dung, and crop waste), and coal, generates harmful household air pollution. This type of air pollution is associated with noncommunicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary disease (COPD), and lung cancer. It is also a risk factor for acute lower respiratory infections in adults and children.

To reduce exposure to indoor air pollution, it is important to improve ventilation in the home. Opening windows or using exhaust fans can help to increase the amount of outdoor air coming indoors and reduce the concentration of indoor air pollutants. In some cases, source control can also be an effective and cost-efficient approach to protecting indoor air quality, such as adjusting gas stoves to decrease emissions. Advanced designs of new homes are starting to feature mechanical systems that bring outdoor air into the home, such as energy-efficient heat recovery ventilators.

Poor ventilation increases indoor pollutant levels, especially from combustion sources

Indoor air quality (IAQ) refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of the occupants. The primary cause of indoor air quality problems is indoor pollution sources that release gases or particles into the air. Inadequate ventilation increases indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by failing to carry indoor air pollutants out of the home.

There are many sources of indoor air pollution in any home, including combustion sources such as building materials and furnishings, like deteriorated, asbestos-containing insulation, and fuel-burning appliances, including cooking stoves, furnaces, and water heaters. These can create emissions that are harmful to health and the environment. Smoke, a byproduct of combustion processes, contains toxic chemicals like formaldehyde and lead.

High temperature and humidity levels can also increase concentrations of some indoor pollutants. Excessive moisture indoors can cause mold problems and promote the growth of dust mites, cockroaches, bacteria, and viruses, which can impact health.

Outdoor air pollutants and allergens can easily enter buildings through open doors and windows, as well as on shoes, clothing, and pets, and even through cracks in the foundation. Natural ventilation, where air moves through open windows and doors, can help to increase the outdoor ventilation rate and reduce exposure to indoor air pollutants, although this may not be sufficient to prevent the buildup of pollutants from smoking or certain short-term activities, such as painting, heating with kerosene heaters, cooking, welding, or soldering.

Indoor air pollution can be tackled with air purifiers, HEPA filters, and exhaust fans

Poor indoor air quality can have adverse effects on health, ranging from irritation of the eyes, nose and throat, to headaches, dizziness, asthma attacks, and even respiratory and heart disease. It may also carry cognitive risks, with one study showing that workers performed worse on cognitive tests when office ventilation rates were lower.

One way to tackle indoor air pollution is to use air purifiers. Portable air purifiers can be particularly useful when outdoor air quality is poor, such as during wildfire smoke events, helping to clean the air inside your home. The CDC recommends using air purifiers with High-Efficiency Particulate Air (HEPA) filters, which can effectively capture and remove a wide range of airborne particles, including smoke, dust, pollen, mold spores, bacteria, and germs. HEPA filters are designed to remove at least 99.97% of particles with a size of 0.3 microns, which is the most challenging particle size to capture.

To further enhance indoor air quality, it is essential to address the sources of indoor air pollution. This can be achieved through source control, which involves keeping contaminants out of the indoor environment. For example, eliminating scented candles and air fresheners that release volatile organic compounds into the air, opting for hardwood floors instead of carpets to reduce dust mites, and adjusting or replacing combustion sources like gas stoves, which can be significant contributors to indoor air pollution.

Additionally, increasing ventilation is a common method to reduce exposure to indoor air pollutants. Opening windows, operating fans, or using exhaust fans in areas where smoking or cooking takes place can help dilute and remove pollutants from the indoor air. Advanced home designs are also incorporating mechanical systems that improve ventilation and bring in fresh outdoor air, such as energy-efficient heat recovery ventilators or air-to-air heat exchangers.

By combining air purifiers with HEPA filters, addressing source control, and improving ventilation, you can effectively tackle indoor air pollution and create a healthier indoor environment.

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