Air quality

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Air quality refers to the presence or absence of air pollution. The presence of substances such as particulates or acid gases (which cause acid rain), or toxins such as dioxin can harm the health of humans and other organisms. Air pollution from human sources has increased greatly in recent centuries; however air quality can also be influenced by the release of these substances from natural sources such as forest fires and volcanoes.

Air quality can be measured by simple physical and chemical methods though these are rapidly being replaced by more sophisticated techniques that use electronics. The simplest and cheapest way of measuring air quality is by analyzing the quality of air.

The Air Quality Index (AQI)[edit | edit source]

The Air Quality Index (AQI) is an indicator of air quality which is previously used to measure Ontario's air quality. The Air Quality Health Index (AQHI) replaced the AQI on June 24, 2015. The AQI is based on air pollutants that have adverse effects on human health and the environment.

AQI (Air Quality Index) number is calculated from 6 key pollutants. While this is true, the AQI formula itself does not use all 6 pollutants in one equation. Rather, each of the 6 pollutants has both a concentration and AQI value. The pollutant with the highest AQI level, or 'risk to health', is deemed the "main pollutant" and that pollutant's AQI determines the overall AQI number across all the included pollutants.

AQI is calculated by using the following formula:

Ip = [(Ihi-Ilow)/(BPhi-BPlow)] (Cp-BPlow)+Ilow,

Where Ip is the index of the pollutant; Cp is the rounded concentration of pollutant p; BPhi is the breakpoint greater or equal to Cp; BPlow is the breakpoint less than or equal to Cp; Ihi is the AQI corresponding to BPhi; Ilow is the AQI corresponding to BPlow.

Open hardware for monitoring air quality[edit | edit source]

See also[edit | edit source]