Air Pollution Index

Satellite image of 2019 Southeast Asian haze in Borneo - 20190915

Air Pollution Index (API) is a numerical scale used to communicate the level of air pollution to the public. It is a crucial tool for environmental monitoring and public health advisories. The API is calculated based on the concentrations of various pollutants in the air, including particulate matter (PM), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃).

History

The concept of an air pollution index was first developed in the 1960s as a means to provide a simple, understandable way to report daily air quality levels to the public. Over time, different countries have developed their own versions of the API, such as the Air Quality Index (AQI) in the United States and the Pollutant Standards Index (PSI) in Singapore.

Calculation

The API is calculated using the concentrations of specific pollutants measured over a set period, typically 24 hours. Each pollutant's concentration is converted into a sub-index value, and the highest sub-index value among the pollutants is reported as the API. The formula and breakpoints for converting pollutant concentrations to sub-index values vary by country and organization.

Health Implications

The API is divided into several categories, each corresponding to a different level of health concern. These categories typically range from "Good" to "Hazardous," with specific health advisories for sensitive groups such as children, the elderly, and individuals with pre-existing health conditions like asthma or cardiovascular disease.

Global Standards

Different countries have established their own standards and breakpoints for the API. For example:

• In the United States, the Environmental Protection Agency (EPA) uses the AQI, which includes breakpoints for PM2.5, PM10, SO₂, NO₂, CO, and O₃.
• In China, the Ministry of Environmental Protection (MEP) uses a similar index but includes additional pollutants like volatile organic compounds (VOCs).

Public Awareness

Public awareness campaigns and real-time reporting of the API are essential for protecting public health. Many countries provide daily API updates through various media, including websites, mobile apps, and public displays.

See Also

• Air Quality Index
• Environmental monitoring
• Particulate matter
• Sulfur dioxide
• Nitrogen dioxide
• Carbon monoxide
• Ozone
• Pollutant Standards Index