Air Pollution Engineers: Enhancing Indoor Air Quality Solutions

Air pollution is a pressing issue that poses a significant risk to human health and prosperity. While outdoor air pollution has been a primary concern, indoor air quality is equally crucial as people spend most of their time indoors. Air pollution engineers play a vital role in improving indoor air quality by identifying and mitigating atmospheric pollutants. They employ various strategies, including source control, improved ventilation, and air cleaning or filtration. Source control involves eliminating or reducing emissions from sources like gas stoves or sealing off asbestos-containing materials. Improved ventilation dilutes indoor air pollutants by increasing the influx of outdoor air through natural means, such as open windows, or mechanical systems like HVAC. Air cleaning or filtration devices, such as HEPA filters, are also used to remove pollutants like mould spores, pet dander, and dust mites. Additionally, the use of natural cleaning products and indoor plants can help purify the air and reduce the concentration of pollutants. Overall, air pollution engineers employ a combination of these strategies to enhance indoor air quality, protect public health, and reduce the adverse impacts of air pollution.

Improving ventilation

For Homes

• Opening windows and doors, operating window or attic fans, or running a window air conditioner with the vent control open increases the outdoor ventilation rate.
• Local bathroom or kitchen fans that exhaust outdoors remove contaminants directly from the room and increase the outdoor air ventilation rate.
• Energy-efficient heat recovery ventilators (also known as air-to-air heat exchangers) are mechanical systems that bring outdoor air into the home.
• Natural ventilation, such as opening windows and doors, can help moderate indoor air temperature and improve indoor air quality by reducing indoor pollutants.
• Infiltration, the process by which outdoor air flows into the house through openings, joints, and cracks, occurs in all homes to some extent and can help improve ventilation.

For Buildings

• Ventilation systems, designed and maintained by air quality engineers, can help improve indoor air quality by bringing outdoor air into the building.
• The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62.1, Ventilation for Acceptable Indoor Air Quality, provides guidelines for achieving good indoor air quality through proper ventilation.
• Mechanical equipment and building surfaces should be maintained in a sanitary condition.
• Significant emission sources, such as large copy machines, should be separated from occupied spaces and air intakes.
• Regular cleaning of occupied areas and good housekeeping practices are important for maintaining good indoor air quality.
• Building maintenance activities, such as pest control and engineering or contractor maintenance, should be carefully managed to ensure they do not negatively impact indoor air quality.
• During renovation activities, discuss indoor air quality concerns with architects and contractors to ensure that materials and procedures used minimize airborne contaminants.
• Modification of the ventilation system may be necessary to resolve indoor air quality complaints. Contaminants can be diluted with outdoor air or managed by changing air pressure relationships between adjoining areas.
• Air cleaning can be used to control indoor air contaminants, especially when the contaminant source is outside the building. Higher-efficiency air filters can be installed in existing HVAC systems.

Using air cleaners/filtration

Air cleaners and filters are an effective strategy to improve indoor air quality. The use of air filtration can supplement source control and ventilation efforts to reduce indoor air pollution.

There are a variety of air cleaners available, ranging from inexpensive tabletop models to whole-house systems. Air cleaners can be highly effective at particle removal, with some utilising High-Efficiency Particulate Air (HEPA) filters, which can remove 99.97% of airborne particles that are 0.3 microns or larger. HEPA filters are often used in hospitals and have been incorporated into home air purifiers.

When selecting an air cleaner, it is important to consider the size of the room and the type of pollutants you want to target. Most air cleaners are designed to filter either particles or gases, so it may be necessary to have two filters or an air cleaner with two filters to target both. For particle removal, the clean air delivery rate (CADR) should be considered, with a higher CADR indicating greater particle filtration and a larger area served. For gas removal, an activated carbon filter or other gas-targeting filter is recommended.

It is also important to note that air cleaners and filters require regular maintenance and replacement to function effectively. Additionally, they should be used in conjunction with other measures to reduce indoor air pollution, such as source control and proper ventilation.

Reducing emissions from individual sources of pollution

Improving Ventilation

Proper ventilation is essential for maintaining good indoor air quality. This can be achieved by:

• Opening windows and doors to increase the amount of outdoor air coming indoors.
• Using local bathroom or kitchen fans that exhaust air outdoors to remove contaminants directly from the room.
• Installing mechanical systems that bring outdoor air into the home, such as energy-efficient heat recovery ventilators.
• Using natural ventilation techniques like opening windows and window shading.

Air Cleaners and Filtration

Air cleaners and filtration systems can help remove pollutants from indoor air. It is important to choose the right type of air cleaner and ensure proper maintenance for effective pollutant removal. Some specific measures include:

• Using High-Efficiency Particulate Air (HEPA) filters, which can remove various pollutants like mould spores, pet dander, and tobacco smoke.
• Opting for green cleaners made with natural ingredients like white vinegar, baking soda, and essential oils instead of conventional cleaning products that contain harmful chemicals.

Source Control

Source control involves eliminating or reducing emissions from individual sources of pollution. Some ways to achieve this include:

• Sealing or enclosing sources that contain asbestos.
• Adjusting gas stoves to decrease emission levels.
• Using electric or gas stoves instead of wood stoves or fireplaces.
• Restricting smoking and vaping to outdoor areas away from doors and windows.
• Avoiding the use of strongly scented products and air fresheners.
• Minimising the use of products containing per- and polyfluoroalkyl substances (PFAS), which can be found in items like stain/water repellents and non-stick cookware.
• Using high-emitting products like paint and glue outdoors or increasing ventilation when using them indoors.

Controlling moisture to prevent mould

Mould is an indoor air pollutant that can cause a variety of health problems, including respiratory infections, asthma, and allergies. It grows in damp and humid environments and can be found in various places in the home, such as walls, floors, ceilings, and basements. Therefore, controlling moisture levels is crucial to preventing mould growth and improving indoor air quality. Here are some measures that can be taken to control moisture and prevent mould:

Identify Moisture Sources

The first step in controlling moisture is to identify the sources of moisture in your home. Common sources include plumbing leaks, roof leaks, condensation on cold surfaces, flooding, and daily activities such as showering, cooking, and indoor drying of clothes.

Repair Leaks and Improve Ventilation

Once the sources of moisture are identified, take action to address them. Repair any plumbing or roof leaks promptly. Improve ventilation in areas prone to moisture, such as kitchens and bathrooms, by using exhaust fans or opening windows during activities that generate moisture. Ensure that exhaust fans are properly vented to the outdoors.

Maintain Humidity Levels

Maintain indoor humidity levels between 30% and 50%. Use a dehumidifier in damp areas like basements to remove excess moisture from the air. Keep windows closed when using a dehumidifier to ensure effectiveness.

Slope the Ground Away from the House Foundation

Ensure that the ground around the foundation of your house slopes away from the structure. This helps prevent water from seeping into your basement and creates a barrier against moisture intrusion.

Promptly Address Water Damage

If your home experiences water damage due to flooding or leaks, act quickly. Dry wet areas within 24 to 48 hours to prevent mould growth. Use fans and dehumidifiers to speed up the drying process.

Use Moisture-Resistant Materials

In areas likely to get wet, such as kitchens, bathrooms, and laundry rooms, use moisture-resistant materials. This includes using waterproof paints and materials that are less susceptible to water damage and mould growth.

Regular Cleaning and Maintenance

Keep your home clean and dry, especially in areas prone to moisture and mould, such as kitchens and bathrooms. Regularly clean and dry surfaces, fix leaks, and address any signs of water damage immediately.

By implementing these measures, you can effectively control moisture levels in your home, prevent mould growth, and improve indoor air quality. Remember that mould can have serious health implications, so taking proactive steps to control moisture is essential for creating a healthy indoor environment.

Using carbon monoxide and radon detectors

Carbon monoxide and radon detectors are crucial tools for improving indoor air quality. Carbon monoxide (CO) is a colorless, odourless, and deadly gas that can quickly reach dangerous levels in enclosed spaces. Radon, similarly, is a radioactive gas that is the leading cause of lung cancer in non-smokers.

The use of detectors and monitors for these gases is an essential step in mitigating their harmful effects. Modern homes, built to be as airtight as possible, can suffer from a lack of circulation, which can contribute to poor air quality. By monitoring levels of these gases, homeowners can take timely action to improve ventilation and protect their health.

Carbon monoxide detectors are designed to alert occupants to the presence of this dangerous gas, often produced by the incomplete combustion of fossil fuels. Radon detectors, meanwhile, can be simple test kits or digital monitors that provide real-time data on radon levels. These detectors are especially important in areas where radon is known to occur naturally, as it can infiltrate homes through cracks in floors and walls, or via the water supply.

Both types of detectors are widely available and easy to use, with some models offering additional features such as mould risk indicators, air quality indices, and notifications when levels of gases exceed safe limits. For example, the Airthings View Plus monitor detects PM2.5, CO2, and radon, while the Lüft® Radon and Indoor Air Quality Monitor measures radon, chemicals, carbon dioxide, temperature, pressure, and humidity.

While these detectors are important tools, it is also crucial to address the sources of indoor air pollution. This may involve reducing emissions from gas stoves, sealing off asbestos-containing materials, and improving ventilation by opening windows and doors, or using fans and air conditioners.

Frequently asked questions