What’s an Air Quality Index, and When Should I Worry About It?

With the recent Canadian wildfires spreading pollution across the Eastern United States, you may have seen a new term popping up all over the news: the Air Quality Index, or AQI. People are understandably scared about the possibility that the very air they’re breathing might be dangerous, but what is the AQI, and when should you really be worried about it? This article cuts through the smog and gets to the details you care about – what the AQI is, when you should be worried, and what precautions you can take to keep yourself safe from air pollution.

Air quality is an essential determinant of our overall well-being, with far-reaching implications for both physical and respiratory health. While it affects everyone, individuals with chronic lung disease face are particularly susceptible to issues related to poor air quality. This is where the AQI comes in. With the rise in pollution levels globally, it becomes imperative for patients with chronic lung disease to pay close attention to the AQI and take necessary precautions to safeguard their respiratory health.

What is the AQI?

The Air Quality Index (AQI) is a standardized measurement system that provides information about the quality of air in a particular area. It considers various pollutants and converts their concentrations into an easy-to-understand index value, ranging from good to hazardous. There are five major types of air pollution that feed into the AQI:

1. Particulate Matter (PM): Fine particles present in polluted air can penetrate deep into the lungs, causing inflammation, oxidative stress, and respiratory irritation. They can worsen symptoms and increase the risk of respiratory infections in patients with chronic lung disease. Inhalation of particulate matter is the major concern in events like the recent Canadian wildfires.
2. Ozone (O3): Ground-level ozone is formed when pollutants like nitrogen oxides react with sunlight. Ozone exposure can lead to airway inflammation, increased respiratory symptoms, and reduced lung function in individuals with chronic lung disease. Ozone pollution comes mainly from industrial sources, and from motor vehicle exhaust.
3. Nitrogen Dioxide (NO2): Commonly emitted by vehicles and power plants, nitrogen dioxide can irritate the airways, exacerbate symptoms, and increase the risk of respiratory infections in patients with chronic lung disease.
4. Sulfur Dioxide (SO2): Industrial emissions and burning fossil fuels release sulfur dioxide, which can aggravate respiratory symptoms, trigger asthma attacks, and worsen lung function in individuals with chronic lung disease.
5. Carbon Monoxide (CO): Carbon monoxide is produced by the incomplete combustion of carbon-containing fuels such as gasoline, coal, natural gas, and wood. When released into the air, it can accumulate in enclosed or poorly ventilated spaces, leading to potential health risks.

The AQI ranges from 0 to 500, with higher numbers corresponding to worse levels of air pollution and increased healthy risks. AQI values above 100 are considered unhealthy, at first for only sensitive groups, but eventually for everyone as the number climbs.

When should I worry about air quality?

While air quality is important for everyone, individuals with chronic lung diseases like chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis, and interstitial lung disease are particularly susceptible to changes in air quality. These conditions are characterized by persistent respiratory symptoms, reduced lung function, and impaired breathing. Patients who have these types of lung problems have increased susceptibility to any sort of irritant that might not cause a problem for those with normal lung function. For patients with chronic lung disease, exposure to polluted air can exacerbate symptoms, trigger acute attacks, and lead to disease progression.

Monitoring the AQI is crucial for patients with chronic lung disease due to the following reasons:

1. Early Warning System: The AQI serves as an early warning system, alerting individuals about poor air quality conditions in their vicinity. By staying informed, patients can take proactive steps to minimize their exposure and protect their respiratory health.
2. Tailoring Activities: The AQI helps patients with chronic lung disease make informed decisions regarding their daily activities. For example, on days with high pollution levels, they can limit outdoor activities, plan indoor exercises, and avoid congested areas.
3. Medication Adjustment: Severe air pollution can necessitate adjustments in medication for patients with chronic lung disease. By closely monitoring the AQI, they can consult their doctor to ensure they have appropriate medications on hand to manage exacerbations.
4. Indoor Air Quality: While outdoor air quality is a concern, maintaining good indoor air quality is equally important. The AQI can guide patients in implementing measures such as using air purifiers, improving ventilation, and avoiding triggers like tobacco smoke and harsh chemicals indoors.
5. Advocacy and Policy Influence: Awareness of the AQI empowers patients to advocate for cleaner air and push for policies that prioritize environmental health. By joining forces with local initiatives, they can contribute to a broader effort to improve air quality and protect vulnerable populations.

People with chronic lung disease should pay particular attention if the AQI increases into the orange category (101-150), signaling and unhealthy level of air pollution for sensitive groups. People without chronic lung disease should be aware of when the AQI rises to the red category (>150), signaling that air pollution is at an unhealthy level for all persons, regardless of their risk factors.

How can I keep myself safe from air pollution?

The best way to stay safe when the AQI rises is to minimize time spent outdoors, and to maximize indoor air quality. If you do find yourself needing to go outdoors, a high quality mask designed to filter small particles, like an N95, can reduce your risk of problems. Indoors, equipment like HEPA filters can be used to filter air, windows should be kept closed, and smoking should be avoided. On a larger scale, using energy-efficient appliances and carpooling or using public transportation are ways to reduce pollution and improve air quality for everyone.

For patients with chronic lung disease, paying attention to the Air Quality Index is of paramount importance, but poor air quality can impact everyone. By staying informed about air quality conditions, individuals can take proactive measures to minimize exposure to harmful pollutants, reduce the risk of exacerbations, and protect their respiratory health. Through increased awareness and collective action, we can strive to create a cleaner and healthier environment for all.