Understanding Aqi: Air Quality Simplified

The Air Quality Index (AQI) is a tool that provides real-time information on the amount of pollution in the air. It is a scale that runs from 0 to 500, with the higher the number, the greater the level of air pollution and the associated health concerns. The AQI is calculated by measuring the concentration of common air pollutants like ozone and particulate matter, and it can be used to advise sensitive groups to take necessary precautions during periods of poor air quality.

How to find the AQI

The Air Quality Index (AQI) is a tool that provides a daily report of the air quality in your location. It tells you how clean or polluted the air is and what associated health effects might be a concern. The AQI uses a scale from 0 to 500, with higher values indicating increased levels of air pollution and potential health risks.

• Visit www.airnow.gov: This website provides air quality data for your local area, as well as state, national, and world views. You can enter your zip code, city, or state to find the AQI for your specific location. The website uses an interactive map and provides a dial or chart with the AQI value and colour for your selected area.
• Check the newspaper: The AQI is often included in the weather section of newspapers.
• Listen to the radio or watch the news: The weather segment on TV or radio may include the AQI for the day and sometimes even provide predictions for the following day.
• Use a mobile app: Air quality-focused mobile apps, such as AirNow, can provide you with real-time air quality data for your location.
• Set up an air quality monitor: You can purchase or set up your own air quality monitor, such as the GAIA air quality monitor. These devices provide real-time air pollution levels for your specific location and can be integrated with maps and APIs to give you a comprehensive understanding of the air quality. You can also refer to real-time air pollution maps for over 100 countries to get an idea of the air quality in your region.

How AQI is calculated

The Air Quality Index (AQI) is a tool developed by the Environmental Protection Agency (EPA) to communicate information about outdoor air quality and health. The AQI is calculated by converting measured pollutant concentrations to a uniform index based on the health effects associated with a pollutant. The health benchmarks used for calculating the AQI are pollutant-specific and are established by the EPA through the National Ambient Air Quality Standards. The Clean Air Act requires the EPA to review these standards every five years.

The AQI is based on the concentrations of five pollutants: ozone, nitrogen dioxide, sulfur dioxide, PM2.5, and PM10. The breakpoints between index values are defined for each pollutant separately, and the overall index is defined as the maximum value of the index. The final AQI value can be calculated per hour or per 24 hours and is the maximum of these six scores. The score for each pollutant is non-linear, as is the final AQI score. The pollutant with the highest AQI value determines the overall AQI for that hour.

AQI values are divided into six categories, each corresponding to a range of index values and represented by a different color. The six categories are: Good, Moderate, Unhealthy for Sensitive Groups (USG), Unhealthy, Very Unhealthy, and Hazardous. An AQI value of 50 or below represents good air quality, while an AQI value over 300 represents hazardous air quality. When AQI values are above 100, air quality is considered unhealthy for certain sensitive groups of people, and as AQI values increase, it becomes unhealthy for everyone.

AQI forecasts take into account factors such as temperatures, precipitation, wind, and cloud cover, as weather conditions can affect pollution creation and transport from other areas. These forecasts help residents make informed decisions to avoid potential health risks associated with poor air quality.

What to do when AQI is high

The Air Quality Index (AQI) is a tool for reporting daily air quality. It tells you how clean or polluted the air is and what associated health effects you might experience within a few hours or days of breathing it in. The AQI uses a scale that runs from 0 to 500, with colours and numbers to indicate the air quality on a given day. The higher the AQI value, the greater the level of air pollution and the greater the health concern.

When the AQI is high, there are several actions you can take to protect your health and reduce your exposure to air pollution. Here are some recommendations:

• Stay away from high-traffic areas, and avoid exercising near those locations.
• On days with very poor air quality (indicated by purple or maroon AQI), try to remain inside as much as possible.
• Keep an eye on the daily air quality index for your region, which you can usually find in the weather forecast, on TV or radio, in the newspaper, or via an app on your phone.
• If you are a member of a vulnerable group, such as children, the elderly, those with asthma or other lung diseases, diabetics, or those with cardiovascular disease, take extra precautions to avoid exposure to polluted air.
• Reduce the amount of time spent outdoors, especially on days with high ozone levels (code red or orange).
• Contact your local officials to express your concerns about the impact of air pollution on your health and to advocate for stricter pollution control measures.

How AQI impacts health

The Air Quality Index (AQI) is a tool used to communicate about outdoor air quality and health. It was developed by government agencies to measure the quality of air and inform the public about the level of air pollution. The AQI tracks six widespread air pollutants, including ozone (smog) and particle pollution.

The AQI value ranges from 0 to 500, with higher values indicating greater air pollution and health concerns. An AQI value of 50 or below represents good air quality, while a value over 300 indicates hazardous air quality and can cause various health issues.

The impact of air pollution on health depends on factors such as the concentration and duration of exposure, individual susceptibility, and other variables. Prolonged exposure to elevated levels of particulate matter and other pollutants can cause irritation and inflammation of the respiratory system, leading to chronic coughing, wheezing, and throat discomfort. It can also result in reduced lung function, exacerbating symptoms for individuals with pre-existing respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD).

Additionally, air pollution can have systemic effects on the body. Fine particulate matter can penetrate deep into the lungs, enter the bloodstream, and travel to other organs, causing tissue damage. This can lead to inflammation, oxidative stress, immunosuppression, and mutagenicity, impacting organs such as the lungs, heart, and brain.

Certain groups are more vulnerable to the health effects of air pollution, including children, the elderly, people with existing health conditions, pregnant women, and those who work or exercise outdoors. It is important for individuals to stay informed about the AQI in their area and take necessary precautions to protect their health when air pollution levels are high.

AQI and wildfires

The Air Quality Index (AQI) is a nationally uniform, colour-coded index developed by the Environmental Protection Agency (EPA) to give the public a tool to understand how good or bad the air is throughout the day. It uses data collected by 5,000 air monitors across the US to track the levels of specific pollutants in the air, assigning a number that corresponds with a colour-coded category. This helps people understand the quality of the air and what activities are safe to do outdoors. The AQI is reported in several ways, but the two most helpful during a wildfire are the AQI forecast and the NowCast AQI, which can be found on AirNow.

The AQI is calculated based on five criteria air pollutants regulated by the Clean Air Act: fine particulate matter (PM2.5), ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. The AQI reports the most common ambient air pollutants, including ozone and particle pollution (PM10 and PM2.5). However, the AQI does not account for all pollutants caused by wildfires. For example, it does not always take into account larger particles such as ash or vapours that may be off-gassing from burned materials. It also does not account for other toxic compounds that may be released during wildfires, such as airborne arsenic, lead, PCBs, VOCs, and burning synthetic materials.

During a wildfire, it is important to use common sense to reduce smoke exposure. Even if the AQI says it is good or moderate, your nose is a good detector, so if the air smells smoky, you should try to stay indoors or find a cleaner air shelter. If you are outdoors and smell smoke or see ash, you may want to wear a mask, especially if you have a respiratory, lung, or heart condition. N95 and P100 respirators are recommended in these situations.

The AQI forecast can help people plan their activities by providing information about when pollution and smoke levels are expected to be highest and when they are expected to be lower. It is important to check the AQI forecast and take the necessary steps to reduce exposure to air pollution, especially for those in sensitive groups, such as children, seniors, pregnant people, and those with respiratory or cardiovascular diseases.

Frequently asked questions