Air Quality Index Explained: As NCR struggles against worsening AQI, learn what 200, 300, 400, 450+ readings mean for your lungs

Understanding the Air Quality Index: What AQI Readings Mean for Your Health in NCR

What is the Air Quality Index (AQI)?

The Air Quality Index (AQI) is a crucial tool used to report daily air quality levels, indicating how air pollution may affect health over short periods. The primary goal of the AQI is to inform the public about local air quality and its potential health impacts. The Environmental Protection Agency (EPA) in the United States calculates the AQI based on five major air pollutants, which adhere to established national air quality standards aimed at protecting public health:

• Ground-level ozone
• Particulate matter (PM2.5 and PM10)
• Carbon monoxide
• Sulfur dioxide
• Nitrogen dioxide

As AQI values rise, so do concerns about air pollution and associated health risks. Many developed countries have utilised the AQI concept for over thirty years, allowing real-time dissemination of air quality information.

How is AQI Calculated?

Different countries utilise various scales to report air quality. In the United States and India, the AQI operates on a 500-point scale, where a rating of 0 to 50 is considered "good," and a rating from 301 to 500 is classified as "hazardous." Daily monitoring stations measure the concentrations of the major pollutants. These raw data points are converted into individual AQI values for each pollutant using standard formulas established by the EPA. The highest value among these is reported as the day's overall AQI.

AQI Categories and Their Implications

• Good (0–50): Minimal impact on health.
• Satisfactory (51–100): May cause slight breathing difficulties in sensitive individuals.
• Moderately Polluted (101–200): Can lead to breathing difficulties for those with lung diseases like asthma, and discomfort for children and older adults.
• Poor (201–300): Prolonged exposure may result in breathing difficulties and discomfort for those with heart conditions.
• Very Poor (301–400): Prolonged exposure may lead to respiratory illnesses, particularly for those with pre-existing lung or heart conditions.
• Severe (401-500): May cause respiratory issues in healthy individuals, while seriously affecting those with lung or heart diseases; even light physical activity can exacerbate difficulties.

Importance of Monitoring AQI

Understanding daily air pollution levels is vital, particularly for individuals with health issues exacerbated by poor air quality. The AQI serves multiple objectives, including:

• Comparing air quality across different locations and cities.
• Identifying inadequate monitoring programs and faulty standards.
• Analysing changes in air quality, whether improvement or degradation.
• Informing the public about environmental conditions, especially benefiting those with pollution-related health concerns.

Who is Most Vulnerable to Air Pollution?

Certain groups are at a heightened risk of health problems related to air pollution:

• Individuals with lung diseases, such as asthma, chronic bronchitis, and emphysema.
• Children and teenagers.
• Active individuals of all ages who spend extensive time outdoors exercising or working.
• Some otherwise healthy individuals who are more sensitive to ozone.

By staying informed about AQI levels, residents of the National Capital Region (NCR) can take necessary precautions to protect their health, especially during periods of high pollution.