Limitations of the Air Quality Index: What is Often Not Revealed

Air Quality Index, commonly abbreviated as AQI, is an international instrument used to quantify levels of air pollution and publicly report these levels as a single value that describes the quality of the air regarding specific pollutants. The AQI is, however not without its limitations and can, therefore, potentially lead to a representation of air quality that is much more favorable than what the actual conditions might suggest.. The following article explains what the AQI tells us and what it leaves out, why there can be such differences between measurements from different sources, and what we can do to better safeguard ourselves against this harmful air.

What the AQI Measures (and What It Misses)

The Air Quality Index (AQI) mainly monitors the levels of five significant pollutants.

1. PM10 and PM2.5: These finely divided particles are generally emitted from sources such as wildfires, vehicle exhaust, and a range of industrial processes.

2. O3: A dangerous gas and a by-product of a chemical reaction when direct sun comes in contact with pollutants.

3. CO: Highly toxic gas; it results when fuel is burning.

4. SO2: This gas is produced through combustion of coal and oil.

5. NO2: These gases are due to vehicle emissions or from an industrial problem.

While these pollutants are very relevant, there are many dangerous pollutants not included in the AQI. A very good example is that of wildfires because they release all sorts of toxic chemicals when buildings, plastics, and treated wood burn. Most of these dangerous substances don't show up reliably in AQI measurements; the air quality can actually be much more dangerous than readings would suggest.

Reasons for the Differences in AQI Readings from Different Sources

While checking air quality on various apps or websites, one would always find a difference in AQI readings. This is because different agencies use different methodologies to estimate the AQI. Here are some reasons for this discrepancy:

Data Sources: some service providers use only official government sensors, while others also incorporate private, low-cost sensors.

Time Delays: Most are not fresh; they are a 24-hour average, although some are updated hourly.

Different Formulas: While some AQI calculators are pegged to short-term spikes in pollution, others reflect long-term averages.

For instance, one day this wildfire season, the Air Quality Index listed Los Angeles as "moderate" on the U.S. Environmental Protection Agency's AirNow website, but a private air quality app graded the air quality as "hazardous." Those kinds of discrepancies make it difficult to determine whether it is safe to go outside.

One more major weakness of the AQI is that the air quality can change drastically from place to place. For example, if there is a raging wildfire nearby, then the amount of pollution in areas with a high concentration will be way higher compared to the less distant areas.

This means that for people living near highways or industrial areas, the AQI can be substantially worse than the general urban readings. Also, AQI does not always issue real-time updates to alert people of sudden spikes in pollution, such as might be caused by a nearby fire or factory accident.

How Air Pollution Affects Different People

AQI provides the general indication of air quality but can't point out the individual effects of pollution. The most vulnerable population to air pollution includes:

Children and elders: Their lungs are more sensitive to the pollutants.

People suffering from asthma, heart disease, or lung conditions: Even "moderate" AQI levels can trigger health problems.

Pregnant women: Air pollution has been linked with complications in pregnancy.


This would even imply that even when AQI records "moderate" or "good" air, the sensitive individual would develop cough, headache, breathing problems, etc.

How to Safeguard Oneself against Air Pollution

As told earlier, most of the times AQI reading mislead and extra caution just in case, becomes a binding necessity. Well here goes a practical approach to just do that:

1. Check Multiple Sources: More than one air quality app or website is needed to ensure that the information is complete. If AQI levels vary in multiple sources, err on the side of caution and take precautions.

If the pollution level is high, it is better to stay indoors. Close all windows and doors, turn on an air purifier with a HEPA filter, and avoid using candles or fireplaces, as those things can further decrease indoor air quality.


2. Wear an N95 Mask Outdoors: If one has to go outdoors when the levels of pollution are extremely high, such as those caused by wildfires, then masks that fit properly will block out the intake of particles that could harm them.

4. Protect Your Health: Be sensitive to coughing, wheezing, or dizziness-even if AQI values appear to be within acceptable levels. Persons with lung and heart disease take precautions as advised by physicians about exposure to air pollutants.

Conclusion

AQI will give you some indication, but do not take it as the complete story behind the pollution of the air. It only reflects some pollutants, and it may vary between various sources. It also may or may not be representative of local air quality or personal health risk. You must ensure that you are checking numerous sources and understand the limitations of the AQI while applying other precautionary measures during these times of heightened pollution levels. Only through an informed and proactive approach can we, and our communities, truly be safe from the dangers of polluted air.