Particle Pollution: Least Effective Reduction Factors

Particle pollution, also known as particulate matter or PM, is a mix of solid particles and liquid droplets in the air. It is one of the six widespread air pollutants that have national air quality standards to limit their levels in the outdoor air. These particles vary in size and are categorised as coarse, fine, and ultrafine. While coarse particles are between 2.5 and 10 micrometres in diameter, fine particles are 2.5 micrometres or smaller, and ultrafine particles are less than 0.1 micrometres. The smaller the particles, the more harmful they are to human health. This article will explore the factors that have the least impact on reducing particle pollution.

Using air conditioning to filter indoor air

Air conditioning can be an effective way to filter indoor air and reduce particle pollution. Here are some ways that air conditioning can be used to improve indoor air quality:

Use Window or Portable Air Conditioners

Window or portable air conditioners can help improve indoor air quality if they recirculate air. By recirculating indoor air, these types of air conditioners can reduce the amount of outdoor particle pollutants that enter the home. It is important to check the user's manual to ensure that the air conditioner has this feature.

Set Central Air Conditioning and Heating Systems to "On"

For those with central air conditioning and heating systems, setting the system to "on" instead of "auto" can help improve indoor air quality. When set to "on," the system constantly filters the air, reducing the amount of particle pollutants in the indoor air.

Install a High-Efficiency Filter

Upgrading to a high-efficiency filter, such as a MERV 13 or higher, can further improve the air conditioning system's ability to filter out particle pollutants. It is important to consult the manufacturer's recommendations or a professional HVAC technician to determine the appropriate filter for your system.

Combine with Air Cleaners or Purifiers

In addition to air conditioning, using portable air cleaners or air purifiers can further enhance indoor air quality. These devices are designed to filter the air in a single room or area and can help remove particle pollutants that may be missed by the air conditioning system.

Ensure Adequate Ventilation

While air conditioning can help recirculate and filter indoor air, ensuring adequate ventilation is also crucial. Opening windows and doors when outdoor air quality is good can bring in fresh air and reduce the concentration of particle pollutants indoors.

Maintain Good Indoor Air Practices

Along with using air conditioning to filter indoor air, it is important to maintain good indoor air practices. This includes reducing indoor sources of particle pollution, such as tobacco smoke, cooking without proper ventilation, burning candles or incense, and using unvented space heaters. Regular cleaning and vacuuming can also help remove particle pollutants from surfaces and improve indoor air quality.

Avoiding outdoor physical activity

When outdoor particle pollution levels are high, limiting physical activity can reduce the inhaled dose of air pollutants. This is because the amount of pollutants inhaled depends on both the concentration in the air and the ventilation rate during breathing. However, it is important to note that the evidence regarding the effectiveness of this measure is limited, and there may be trade-offs between the benefits of physical activity and the risks of exposure to air pollution.

For example, while avoiding outdoor exercise may reduce exposure, it could also lead to a decrease in the positive health effects of regular physical activity. Therefore, it is recommended to modify the time and location of physical activity rather than avoiding it altogether. This could include choosing indoor activities, exercising away from pollution sources or busy roads, or altering the time of day to avoid peak pollution levels.

Additionally, it is worth noting that indoor air quality can also be influenced by outdoor particle pollution, especially if there is insufficient ventilation. In such cases, using air conditioning or air purifiers with high-efficiency filters can help reduce indoor pollutant levels.

Overall, while avoiding outdoor physical activity can be a strategy to reduce exposure to particle pollution, it should be considered alongside other measures and tailored to the specific circumstances and susceptibility of individuals.

Using air quality alerts

Air quality alerts are an important tool to protect yourself and others from the harmful effects of particle pollution. Particle pollution, or particulate matter (PM), is a complex mixture of small solid particles and liquid droplets found in the air. These particles can be harmful to human health, especially the smaller particles known as PM2.5, which can penetrate deep into the lungs and even enter the bloodstream.

Understanding Air Quality Index (AQI)

The Air Quality Index (AQI) is a useful tool provided by AirNow that tells you how clean or polluted the outdoor air is. It translates air quality data into numbers and colours, making it easier for people to understand the current air quality and take appropriate action. The AQI is available on AirNow's website and through notifications.

Adjusting Activities

When air quality alerts indicate unhealthy levels of particle pollution, it is important to adjust your activities accordingly. This is especially crucial for sensitive groups, such as children, teenagers, older adults, people with heart or respiratory problems, pregnant people, and those who work or exercise outdoors. During such times, it is recommended to spend more time indoors, reduce outdoor activities, and wear a well-fitting face mask, preferably an N95 or KN95, when outdoors. Schools, childcare facilities, employers, and activity programs should plan for more indoor activities to protect vulnerable individuals.

Indoor Air Quality

While spending more time indoors can help reduce exposure to outdoor particle pollution, it is also important to maintain good indoor air quality. Consider using air cleaners, window or portable air conditioners, and stand-alone fans to improve indoor air circulation and reduce particle levels. Additionally, avoid indoor activities that can contribute to particle pollution, such as smoking, frying food, or burning candles. Open windows and doors when outdoor air quality is good to bring in fresh air.

Notifications and Flag Programs

Stay informed about air quality alerts by signing up for notifications from AirNow or similar services. The Air Quality Flag Program is another useful initiative where organisations raise a flag to indicate the air quality for the day, helping community members easily recognise when to take action.

Long-term Strategies

While air quality alerts are crucial for taking immediate action, it is also important to support long-term strategies to reduce particle pollution. This includes regulations and programs aimed at reducing emissions from vehicles, industrial plants, and power generators, which are major sources of particle pollution.

Using air purifiers

Air purifiers are an effective way to reduce particle pollution, but they are not a cure-all. They are most effective when used in conjunction with other methods, such as improving ventilation and controlling the source of contaminants.

When choosing an air purifier, it is important to consider the specific needs and dimensions of the space you want to clean. Here are some key factors to keep in mind:

• Type of filter: HEPA (High-Efficiency Particulate Air) filters are highly effective at capturing particles, including dust, pollen, mold, and bacteria. They are designed to collect at least 99.5% of particles that are 3 microns or less in size. For the best results, look for a HEPA filter with a rating of at least MERV 13.
• Clean Air Delivery Rate (CADR): This is the volume of clean air your device will re-circulate, expressed in cubic feet per minute. As a general rule, the CADR of your air purifier should be equal to at least two-thirds of the room's area. For wildfire smoke or other intense pollution, the CADR should match the square footage of the room.
• Targeted pollutants: Different air purifiers are designed to target specific types of pollutants. For example, if you want to remove gaseous pollutants like volatile organic compounds (VOCs), you will need a purifier with an activated carbon filter. If you're specifically targeting viruses and bacteria, look for a purifier that uses UV light.
• Room size: The purifier should be designed for the size of the room you intend to use it in. A purifier that is too small for the space will not be effective, no matter how powerful it is.
• Portability: If you plan to move the purifier between rooms, look for a lightweight, portable model. Some purifiers can also be mounted on walls, and there are even wearable and desktop versions available.
• Maintenance: All filters need regular replacement as per the manufacturer's instructions. A dirty or overloaded filter will not work effectively.

In addition to these factors, it is important to address the source of the particle pollution as much as possible. This could include simple steps such as regularly cleaning your home to prevent dust accumulation, avoiding smoking indoors, and improving ventilation by opening windows and using fans.

By choosing the right air purifier for your needs and combining it with other strategies for reducing particle pollution, you can effectively improve your indoor air quality.

Avoiding candles and incense

Burning candles, incense, and wood are common indoor sources of particle pollution. Particle pollution, also known as particulate matter (PM), is a mixture of solid particles and liquid droplets found in the air. These particles can be emitted directly from sources such as construction sites, unpaved roads, fields, smokestacks, and fires. When candles are burned, they release carcinogenic toxins, such as benzene, toluene, formaldehyde, acetaldehyde, acrolein, and soot into the air. Similarly, incense can be a major source of particulate matter and is designed to produce soot.

The emissions from paraffin candles, which are made from petroleum, contain many of the same toxins produced by burning diesel fuel. These candles, along with scented or aromatic candles, are the most common offenders on the market. The fragrances in scented candles can also cause reactions in people prone to allergies. In addition, the dye used in coloured candles contains benzidine, which is linked to an increased risk of bladder cancer.

To reduce exposure to particle pollution from candles and incense, it is recommended to:

• Limit their use and opt for electric or gas heaters instead of wood stoves or fireplaces.
• Choose unscented, fragrance-free, and uncoloured candles made from highly-refined wax, such as beeswax or soy.
• Ensure proper ventilation in the room when burning candles or incense.
• Follow fire safety guidelines, such as trimming the wick, using a wick dipper, and never leaving a candle unattended.
• Consider alternatives like flameless candles, wax melts, or oil lamps.

Frequently asked questions