Air Pollution In Homes: What's The Quality Like Indoors?

Air pollution is a serious global issue, and while we often associate it with outdoor environments, it is also a significant problem in our homes. Indoor air pollution is caused by various factors, including inefficient ventilation, the use of polluting fuels for cooking and heating, and the presence of allergens and toxins. This issue is particularly prevalent in developing countries, where solid fuels such as wood, crop waste, and charcoal are commonly burned indoors, and it can have severe health consequences, including respiratory problems, cardiovascular issues, and even certain types of cancer. With people spending the majority of their time indoors, understanding and addressing household air pollution are crucial steps towards improving public health and reducing the burden of pollution-related diseases.

Indoor air pollution sources

Indoor air pollution is a serious issue, with various sources contributing to poor air quality in homes. Here are some of the key indoor air pollution sources:

Combustion and Fuel-Burning Appliances:

• The use of inefficient and polluting fuels, such as solid fuels (wood, crop waste, charcoal, coal, and dung) and kerosene, for cooking and heating, releases harmful emissions.
• Fuel-burning appliances, including cooking stoves, furnaces, and water heaters, can emit dangerous pollutants, especially if improperly maintained or vented.
• Gas stoves, if not properly adjusted, can emit high levels of carbon monoxide, and gas ranges used for cooking can produce nitrogen oxide, a respiratory irritant.
• Fireplaces, chimneys, and wood stoves without proper ventilation can release pollutants like hydrocarbons and back-drafted smoke into the living space.

Building Materials and Products:

• Building materials, such as paint, carpets, and textiles, can release pollutants. For example, certain types of paint can emit volatile organic compounds (VOCs).
• Home improvement products, including cleaning supplies and air fresheners, can also be sources of indoor air pollution.

Biological Pollutants:

• Plants, people, and animals are sources of indoor biological pollutants.
• Mold and mildew, often caused by excessive moisture, release disease-causing toxins and can trigger allergies and respiratory issues.
• Contaminated central air handling systems can become breeding grounds for certain types of asthma and infectious illnesses like influenza, measles, and chickenpox.

Outdoor Air Pollution:

• Outdoor air pollutants can easily enter indoor spaces through open doors and windows, as well as on shoes, clothing, and pets.
• Inadequate ventilation can increase indoor pollutant levels by not diluting emissions and carrying pollutants out of the indoor space.

Human Activities:

• Smoking, cleaning, redecorating, and hobbies can release pollutants into the indoor environment.
• Incomplete or improper removal of certain building materials, such as asbestos, can release harmful fibers into the indoor air.

Health risks of household air pollution

Household air pollution is a serious health risk, causing 6.7 million premature deaths annually. The burning of solid fuels, such as wood, charcoal, coal, and kerosene, in open fires and inefficient stoves, is a major source of indoor air pollution. The use of polluting fuels and technologies in and around the home releases a range of health-damaging pollutants, including small particles that penetrate deep into the lungs and enter the bloodstream.

The health effects of household air pollution are far-reaching and include both immediate and long-term impacts. Immediate effects of exposure to indoor air pollutants can include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. These symptoms are usually short-term and treatable, and may fade or disappear when the person is no longer exposed to the pollution source. However, repeated or prolonged exposure to indoor air pollutants can lead to more severe and long-lasting health issues.

One of the most significant risks associated with household air pollution is the development or exacerbation of respiratory diseases. Exposure to indoor air pollution almost doubles the risk of acute lower respiratory infections in children and contributes to a significant number of pneumonia deaths in children under five. In adults, household air pollution is responsible for 22% of all pneumonia-related deaths and 19% of chronic obstructive pulmonary disease (COPD) cases.

Additionally, household air pollution has been linked to an increased risk of non-communicable diseases such as stroke, ischaemic heart disease, and lung cancer. The ingestion of kerosene by accident is the leading cause of childhood poisonings, and the use of polluting fuels and inefficient stoves for cooking, heating, and lighting has been associated with severe burns and injuries, particularly in low- and middle-income countries.

Women and children are disproportionately affected by the health risks of household air pollution as they typically carry out household chores such as cooking and collecting firewood, spending more time exposed to harmful smoke and pollutants. The use of inefficient and polluting fuels also requires significant time for gathering, preparing, and using fuel, limiting opportunities for education, leisure, and other productive activities. Furthermore, in less secure environments, women and children are at risk of injury and violence while gathering fuel.

Clean air solutions for homes

Poor indoor air quality can cause or worsen lung diseases, and in some cases, even lead to death. Household air pollution exposure leads to non-communicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary disease (COPD), and lung cancer, low birth weight, tuberculosis, and more. In poorly ventilated dwellings, indoor smoke can have levels of fine particles up to 100 times higher than acceptable.

To improve indoor air quality, it is important to reduce or remove sources of indoor air pollutants and to ventilate with clean outdoor air. Here are some clean air solutions for homes:

• Use clean fuels and technologies: The World Health Organization (WHO) recommends the use of clean fuels and technologies such as solar, electricity, biogas, liquefied petroleum gas (LPG), natural gas, alcohol fuels, and biomass stoves that meet emission targets. Avoiding the use of kerosene and unprocessed coal can also help reduce household air pollution.
• Improve ventilation: Increasing ventilation by opening windows or using fans can help reduce indoor air pollution. Running an air conditioning system with a good filter can also improve indoor air quality.
• Use air purifiers: Portable air purifiers can help remove pollutants from the air, especially in smaller spaces such as bedrooms, offices, and living rooms. Look for purifiers with high Clean Air Delivery Rates (CADR) and consider smart capabilities for added convenience.
• Reduce indoor pollutants: Some sources of indoor air pollution include cooking, cleaning, second-hand smoke, building materials, and consumer products. Reducing these pollutants, such as by switching to non-toxic cleaning products or reducing exposure to second-hand smoke, can improve indoor air quality.
• Control moisture: Excessive moisture indoors can promote the growth of mould, dust mites, cockroaches, bacteria, and viruses. Controlling moisture through proper ventilation and dehumidification can help improve indoor air quality.
• Regular cleaning: Regularly cleaning surfaces with soap, detergent, or all-purpose cleaner can help reduce viruses and bacteria. Vacuuming and dusting can also help remove allergens and pollutants from surfaces.

Fuel-burning appliances and health

The use of fuel-burning appliances at home, such as cooking stoves, furnaces, and water heaters, can have significant health impacts. These appliances can emit harmful pollutants, including carbon monoxide, nitrogen oxides, and particulate matter, which can adversely affect indoor air quality and subsequently, our health.

One of the critical health risks associated with fuel-burning appliances is carbon monoxide (CO) poisoning. Incomplete combustion of fuels, such as gas, oil, kerosene, or wood, can lead to the production of CO. This colorless and odorless gas can be deadly if accumulated to high levels in poorly ventilated areas. Proper installation, maintenance, and use of appliances fueled by these sources are crucial to mitigate this risk. Additionally, ensuring adequate ventilation and regular cleaning of chimneys, flues, and other exhaust systems are essential to prevent the buildup of harmful gases.

The combustion of fuels in appliances also contributes to indoor particulate matter pollution. Fine particles can penetrate deep into the lungs and enter the bloodstream, causing or worsening lung diseases. In poorly ventilated homes, indoor smoke can reach levels of fine particles up to 100 times higher than acceptable limits. Prolonged exposure to these particles can lead to coughing, wheezing, asthma attacks, and increased risks of heart attacks, lung cancer, and even premature death.

The use of fuel-burning appliances also has environmental implications, contributing to global warming emissions. Petroleum-based fuels, including natural gas, propane, fuel oil, and kerosene, are major drivers of these emissions. To protect our health and the environment, it is essential to transition to cleaner fuels and technologies, as recommended by organizations like the World Health Organization (WHO). These include solar, electricity, biogas, liquefied petroleum gas (LPG), and natural gas, which produce fewer emissions and are considered cleaner alternatives for household energy needs.

The impact of outdoor air pollution on indoor air quality

Spending the majority of our time indoors means that exposure to air pollution in our homes is a pressing concern. Indoor air quality is influenced by both indoor and outdoor sources of air pollution. While most indoor air pollutants come from indoor sources, outdoor air pollution can infiltrate homes and significantly impact indoor air quality.

Outdoor air pollution can enter homes through open windows and doors, ventilation systems, and cracks in walls, doors, and window sealants. This is particularly true during extreme air pollution events like wildfires, when opening windows and doors to ventilate the home can worsen indoor air quality. Outdoor air pollutants that enter the home include particulate matter, ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead. These pollutants can have severe health impacts, including irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue, respiratory diseases, heart disease, and cancer.

Several factors influence the interaction between indoor and outdoor air pollutants, including individual behavior and the surrounding environment. For example, energy-efficient building construction without sufficient mechanical ventilation can increase indoor concentrations of pollutants. Additionally, outdoor climate and weather conditions affect whether occupants keep windows open or closed and whether they use air conditioners, humidifiers, or heaters, all of which can impact indoor air quality.

Understanding the relationship between indoor and outdoor air quality is crucial for minimizing the health effects of air pollutants. While outdoor air pollution can worsen indoor air quality, taking steps to improve ventilation, minimize outdoor pollutant infiltration, and reduce indoor sources of pollution can help improve overall air quality in homes.

Frequently asked questions