Air Quality Alert: What's Making It So Bad?

Poor air quality can have a range of negative health effects, from irritating the eyes, nose, and throat to more serious problems like lung damage, asthma attacks, and heart attacks. Children, older adults, and people with certain health conditions are especially vulnerable to the impacts of air pollution. Both outdoor and indoor air quality can be affected by various factors, including weather conditions, proximity to high-traffic areas, and the accumulation of contaminants from different sources. Understanding and monitoring air quality is crucial to protect ourselves and our loved ones from the harmful effects of air pollution.

Outdoor air pollution: ozone, particle pollution, and weather conditions

Outdoor air quality is influenced by a combination of factors, including ozone levels, particle pollution, and weather conditions.

Ozone, a colourless gas composed of three oxygen atoms, can be either beneficial or harmful depending on its concentration and location in the atmosphere. Stratospheric ozone is beneficial as it shields the Earth from harmful ultraviolet radiation. In contrast, ground-level ozone is considered a harmful air pollutant and is the primary component of smog. It is formed through complex chemical reactions between oxides of nitrogen and volatile organic compounds, which are emitted by vehicles, power plants, industrial boilers, and other sources. Ground-level ozone can irritate the lungs, causing coughing, breathing difficulties, and increased susceptibility to infections and lung diseases. It is particularly harmful to children, the elderly, and individuals with pre-existing lung conditions such as asthma.

Particle pollution, another critical component of outdoor air quality, refers to the presence of fine solid or liquid particles in the air. These particles can include smoke, dust, and other aerosols, emitted directly or resulting from chemical transformations. Sources of particle pollution include vehicles, factories, power plants, fires, and various human activities. This type of pollution can lead to coughing, wheezing, reduced lung function, asthma attacks, and even more severe health issues such as heart attacks and strokes. Wildfires significantly contribute to particle pollution, releasing harmful particulate matter and gases, including nitrogen dioxide, volatile organic compounds, and carbon monoxide. These emissions play a crucial role in the formation of ozone, especially under sunny and hot weather conditions.

Weather conditions play a significant role in determining outdoor air quality. Sunshine, temperature, rain, wind speed, air turbulence, and mixing depths all influence the concentration and dispersal of pollutants. Sunshine, for example, can trigger chemical reactions that lead to the formation of smog, while higher temperatures accelerate these reactions. Rain typically reduces pollution by washing away particulate matter and soluble pollutants. Wind speed and air turbulence impact the dispersal of pollutants, affecting their concentration in specific areas. Therefore, understanding the interplay between these weather factors and pollution sources is essential for comprehending outdoor air quality dynamics.

Indoor air pollution: tobacco smoke, aerosol sprays, and poor ventilation

Indoor air pollution is a serious issue that can have a significant impact on health. People often underestimate the extent of the problem, focusing on outdoor sources of pollution, such as factories, without considering the many contaminants found within their own homes. On average, Americans spend 70-90% of their time indoors, with more than half of that time spent at home, so it is important to ensure that indoor air quality is well-managed.

Tobacco smoke is a major contributor to indoor air pollution. The combustion of cigarettes and other tobacco products releases harmful chemicals and particles into the air, which can be inhaled by occupants. Even if no one is actively smoking indoors, secondhand smoke can still enter the home from outside sources, such as neighbouring apartments or outdoor areas where smoking takes place.

Aerosol sprays, perfumes, and fragrances are another source of indoor air pollution. These products release tiny particles and chemicals into the air, which can accumulate and be inhaled. While they may not seem as harmful as tobacco smoke, they can still contribute to poor indoor air quality, particularly if used frequently or in enclosed spaces with inadequate ventilation.

Poor ventilation can exacerbate the problem of indoor air pollution by allowing contaminants to build up. Inadequate ventilation means that outdoor air is not able to dilute emissions from indoor sources, and indoor pollutants are not carried out of the home. Ventilation systems, such as HVAC systems, should be properly maintained and regularly cleaned to ensure they are functioning effectively. Filters should be replaced frequently to prevent clogging and the growth of bacteria and mould, which can then be distributed throughout the home.

The health effects of indoor air pollution can be serious and range from short-term to long-term issues. Headaches, eye irritation, fatigue, dizziness, and respiratory problems are all common symptoms of poor indoor air quality. Prolonged exposure to certain pollutants can lead to more severe health issues, including heart disease, lung cancer, and respiratory illnesses such as asthma and COPD. It is important for individuals to be aware of the potential risks and take steps to improve indoor air quality, such as increasing ventilation, reducing the use of aerosol sprays, and avoiding smoking indoors.

Health risks: respiratory issues, cardiovascular problems, and eye irritation

Poor air quality can lead to a range of respiratory issues. Air pollution is the presence of contaminants in the atmosphere, such as dust, fumes, gases, mist, odours, smoke, and vapours. These pollutants are inhaled, leading to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, particularly impacting the lungs. Short-term exposure to fine particles in the air can aggravate lung disease, trigger asthma attacks and acute bronchitis, and increase the risk of respiratory infections. Over time, breathing in these fine particles increases the chances of developing chronic obstructive pulmonary disease (COPD), chronic bronchitis, and lung cancer.

Fine particulate matter, with diameters less than 2.5 µm or PM2.5, is of particular concern. These particles can penetrate deep into the lungs, enter the bloodstream, and travel to other organs, causing systemic damage to tissues and cells. This can lead to reduced lung function and an increased risk of respiratory infections. Outdoor particle pollution exposure is especially harmful, and certain areas, such as near roadways, railyards, seaports, or industrial areas, may have higher levels of PM2.5.

Air pollution also poses significant risks to cardiovascular health. It can exacerbate existing cardiovascular conditions and contribute to the development of cardiovascular disease. The evidence is particularly strong for the impact of outdoor particle pollution, specifically fine particulate matter (PM2.5). Exposure to increased concentrations of PM2.5 over a short period can trigger cardiovascular events, such as heart attacks. Longer-term exposure is associated with an increased risk of cardiovascular mortality and decreased life expectancy.

Additionally, air pollution can contribute to eye irritation. While there is limited direct evidence of the impact of air pollution on eye health, it is known that pollutants can enter the body through the eyes. The eyes are also sensitive to irritants, and air pollution can potentially lead to eye strain and other ocular issues.

Air Quality Index: AQI forecasts, maps, and local alerts

The Air Quality Index (AQI) is a system that warns the public about dangerous levels of air pollution. It is calculated based on the levels of five major air pollutants: ground-level ozone, particle pollution (or particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. These pollutants are known to have harmful health effects, especially for vulnerable individuals such as children, the elderly, and people with pre-existing health conditions.

The AQI is divided into six categories, each with a corresponding colour and recommendations for protective actions. When the AQI value exceeds 100, the air quality is considered unhealthy, and the risk to public health increases. It is important to stay informed about the AQI in your local area and take necessary precautions to minimise potential health risks.

There are various tools available to access AQI forecasts and real-time data. Websites, mobile apps, and interactive maps provide up-to-date information on air quality. For example, AirNow.gov offers an interactive map with data for air quality monitors in the U.S., Canada, and Mexico. The map includes features such as forecast loops and archive data, allowing users to track changes in air quality over time.

Additionally, local weather forecasts often include AQI information, such as "code orange" days, indicating elevated levels of air pollution. Newspapers, radio, television, and weather apps on mobile phones are other sources of local AQI data. The EPA also provides year-round AQI forecasts with maps that show how pollution levels change and move throughout the day.

By utilising these resources, individuals can make informed decisions to protect their health. For instance, on days with high AQI values, it is advisable to limit outdoor activities, stay indoors, and use air purifiers if possible. Staying informed about the AQI can help individuals take proactive measures to minimise the potential health risks associated with air pollution.

Action plan: limiting outdoor time, wearing masks, and indoor activities

Air pollution can be harmful to anyone, but some people are especially vulnerable to its adverse effects. This includes children and teens, the elderly, people with asthma and other lung diseases, those who are pregnant, and people with diabetes or cardiovascular disease. Even healthy adults who spend a lot of time outdoors or exercise vigorously can experience negative health consequences from poor air quality.

When the air quality is poor, it is essential to take proactive steps to safeguard your health and that of your loved ones. Here is an action plan with specific recommendations to follow:

• Limit outdoor time: Reducing the amount of time spent outdoors is crucial when air pollution levels are high. The longer you remain outdoors in poor air quality, the higher your chances of developing health issues. Adjust your daily plans to minimize prolonged exposure to polluted air. Opt for indoor activities and avoid extended periods of outdoor exercise or strenuous work.
• Wear masks: When venturing outdoors, consider wearing a well-fitted mask, such as an N95 respirator, to provide a barrier against harmful pollutants. Masks can help filter out particulate matter and reduce the amount of contaminated air you inhale.
• Stay informed: Stay updated about the air quality in your area by checking the Air Quality Index (AQI) or using air quality monitoring apps. The AQI provides a numerical value and color-coded categories to indicate the level of air pollution. When the AQI exceeds 100, the air quality is considered unhealthy and may require additional precautions.
• Avoid high-traffic areas: Keep away from areas with heavy traffic, as these zones tend to have higher levels of air pollution due to vehicle emissions. If possible, choose less congested routes for your outdoor activities or opt for green spaces and parks where air quality may be relatively better.
• Indoor activities: When outdoor air quality is poor, focus on indoor activities that don't involve strenuous exercise or deep breathing. This could be a perfect time to catch up on reading, watch movies, play board games, or engage in light indoor hobbies and crafts.
• Improve indoor air quality: Ensure that your indoor air quality remains as good as possible. Keep windows closed during periods of high outdoor pollution, and consider running an air conditioner with a recirculate setting to filter and maintain clean air inside your home. Regularly check and replace air filters as needed. Avoid high-heat cooking and the use of gas stoves, opting for a microwave instead to reduce nitrogen dioxide (NO₂) fumes and other pollutants.

Remember, while it may be safe to engage in light outdoor activities during moderate air quality days, always prioritize your health and well-being. If you or your family members belong to a vulnerable group, take extra precautions and limit outdoor exposure when air pollution levels are elevated.

Frequently asked questions