The quality and condition of the air that we breathe has been steadily declining over the years. It has become an urgent concern because of the increasing health problems arising due to the intake of bad quality air. Although there are specific cities in India that suffer from the severest air quality, we need to look at the problem from a broader perspective.
Breathing clean air has become alarmingly uncommon, especially so in big cities. The air quality index pollutants in the rapidly developing cities such as Delhi have reached dreadful heights. Each year, the residents face growing problems because of it, notably so during the winter season.
However, this does not mean that air pollution is only a problem in one or two cities. Even the cities with the best air quality index in India does not ensure healthy quality of air. Knowing about the significant air quality index pollutants can be helpful to determine the necessary measures to reduce its impact.
But, first, let’s understand how the national air quality index works.
What is Air Quality Index?
The national air quality index is a measurement of the air quality index pollutants on any given day. It is calculated on a daily basis to help understand the impact on the local population. Depending on the country, different parameters and scales are used to report the air quality index pollutants.
There are five major air quality index pollutants according to which the Environmental Protection Agency (EPA) calculates the national air quality index. These are:
- Ground-level ozone
When you hear ozone layer, you think of the protective layer in the atmosphere that protects us against the damaging ultraviolet rays from the sun. But, you may be surprised to know ozone at ground-level is among the worst air quality index pollutants.
Smog is mainly made up of ground-level ozone, which is the product of sunlight and vehicular emissions. During the summer months, it is readily created and remains at the highest concentrations in the afternoons. It can be detrimental to health, even at low levels.
- Particle pollution/particulate matter (PM2.5/pm 10)
Particulate matter refers to minute solid particles or liquid droplets present in the air. It can include a variety of components such as soil, metal or dust particles, organic compounds, nitrate, sulfates, etc.
Their impact on health depends on the size of the particulate matter, i.e., PM 2.5 or PM 10. The smaller the particle, the easier they can reach the lungs or even enter the bloodstream.
- Carbon Monoxide
Carbon monoxide is formed when the carbon in fuels doesn’t burn completely. The main sources of such air quality index pollutants are motor vehicles, industries, wood-burning heaters, bushfires, etc. They are highly present in the air during colder weather and can cause harmful effects on a person’s health. It reduces the amount of oxygen reaching different parts of the body.
- Sulfur dioxide
These are the air quality index pollutants which are by the combustion of fossil fuels and industrial facilities. Some natural processes such as decomposition also contribute to it. Prolonged exposure to it can result in respiratory and cardiovascular diseases.
- Nitrogen dioxide
This is another air quality index pollutant formed by emissions from vehicles, industries, and gas-heaters. There is a significant amount of it present on busy roads. Like the other air quality index pollutants, it can lead to respiratory problems in people.
In India, we follow the 500 point scale to record the air quality index pollutants. Here’s how it works:
Good (0–50) – The impact is minimal.
Satisfactory (51–100) – It can lead to minor difficulties in breathing in people who are sensitive to it.
Moderately polluted (101–200) – If the air quality index pollutants rate within this bracket, it can lead to more serious breathing problems in people who suffer from respiratory issues such as asthma or heart diseases.
Poor (201–300) – A rating within this bracket can cause breathing issues and discomfort upon prolonged exposure.
Very Poor (301–400) – This may result in the development of respiratory disorders among people if they are exposed to it for long. People suffering from heart problems or lung diseases are at a greater risk.
Severe (401-500) – If the air quality index pollutants fall in this bracket, it can lead to respiratory diseases in healthy people and a more pronounced impact on people with lung or heart problems.