Be Air Aware
When we talk about air pollution we must know it in more concrete terms. Today the level of pollution can be measured using AQI or US AQI. This is an index to show the air quality. It is measured on a scale that ranges from 0 to 500.
An AQI value of 100 normally corresponds with the Air Quality Standard for Protection of Public Health. This means if the ambient air pollution level of your area is 100 or less than 100, you should not be worried, but it is more than 100 than you do need to worry.
The AQI measures Five Major Pollutants. I hope everyone knows what is a pollutant? Well, it is a substance that pollutes or changes the normal/healthy consistency of a given medium, here the air is the medium we are talking about. So the five pollutants are;
1) 1). Ground-level Ozone
2) 2). Particle Pollution: It is measured as PM2.5 and PM10 where PM stands for Particulate Matter.
3) 3).Carbon Monoxide (CO)
4) 4). Sulfur Dioxide
5) 5). Nitrogen Dioxide
The concentration of these pollutants in air is directly related to health issues. Most of them are related to respiratory diseases and death due to over exposure to them.
It must be noted that there are many particles that are released from terrestrial and marine ecosystems, such as fungi, pollen, bacteria and viruses. They are present in the form of bio-aerosol and transported through wind. AQI measures the particles based on size but does not specify the type.
The AQI is user friendly. It is divided into six catagories which are demarcated with a special colour. These colours correspond to a different level of health concern. Let us take a look at it.
|
Daily AQI Colour |
Levels of Concern |
Values of Index |
Description of Air Quality |
|
Green |
Good |
0 to 50 |
Air quality is satisfactory, and air pollution poses little or no risk. |
|
Yellow |
Moderate |
51 to 100 |
Air quality is acceptable. However there may be a risk for some people, particularly those who are usually sensitive to air pollution. |
|
Orange |
Unhealthy for sensitive groups |
101 to 150 |
Members of sensitive groups may experience health effects. The general public is less likely to be affected. |
|
Red |
Unhealthy |
151 to 200 |
Some members of the general pulic may experience helath effects; members of sensitive groups may experience more serious health effects. |
|
Purple |
Very unhealthy |
201 to 300 |
Health alert: The risk of health effects is increased for everyone. |
|
Maroon |
Hazardous |
301 and higher |
Health warning of emergency conditions: everyone is more likely to be affected. |
Let us know a bit more about the pollutants:
1) Ground Level Ozone
It is quite strange that Ozone layer around the Earth protects us from the harmful radiations of Sun but Ozone in the lower region is a major pollutant that forms Smog and causes respiratory diseases.
How is it formed?
Human activities produce lot of smoke from the vehicles and factories containing primary pollutants in the form of Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOCs). When these pollutants react in sunlight and stagnant air, the secondary pollutant, Ground-level Ozone is produced.
2) Particle Pollution
Suspension of microscopic solid and liquid particles floating in the air refer to particulate pollution.
How is it formed?
It is formed through natural or anthropogenic sources.
· Smoke is produced by combustion of organic matter. For example; cigarette, garbage, dry leaves,fossel fuel, oil, forest fire, etc.
· Dust more than 1 micrometer in diameter originates from grinding and crushing, wood work (saw dust), Pulversization of coal, release of fly ash, cement dust, dust storms.
· Mist is formed by condensation of vapours in the air containing herbicides and pesticides.
3) Carbon Monoxide
It is a toxic air pollutant.
How is it formed?
It is produced by incomplete combustion of carbon containing fuels, such as natural gas, gasoline, oil, coal, and wood.
It is mostly produced by vehicle emissions.
Sulfer Dioxide SO2
Sulfer Dioxide is a bad smelling toxic gas. It is a part of a bigger group known as Sulfer Oxides (SOx).
These gases are produced by burning of fossil fuels like, coal, oil and diesel.
Sources include power plants, metal processing facilities, and vehicles.
When it is released it forms sceondary pollutants like sufate aerosols, PM, and acid rain.
It contributes in the formation of smog which can impair visibility.
Nitrogen Dioxide NO2
NO2 is a gaseous pollutant. It is part of a bigger group of gases called Nitrogen Oxides or NOX.
These gases are produced by burning of fossil fuels like coal, oil, gas, or diesel.
Sources include cars, trucks, buses, etc., which are the main sources.
What have we learnt?
- We can always check the quality of air we are breathing in our respective area.
- We can analyse the reason or the major pollutants present in our area.
- We can arrive at proper solutions to do away with air pollution in our area.
