PM 2.5, Sulphur Dioxide, and more: What are the pollutants in our air, and how they impact health

  • November 8, 2023
  • Posted by: OptimizeIAS Team
  • Category: DPN Topics
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PM 2.5, Sulphur Dioxide, and more: What are the pollutants in our air, and how they impact health

Subject: Environment

Section: Pollution

Context:

  • Rising pollution levels in north India have led to focus returning on the Air Quality Index (AQI) score, a measure of air pollution.

AQI Index score:

  • The AQI transforms complex air quality data of various pollutants into a single number for ease of understanding. The pollutants include PM 10, PM 2.5, Nitrogen Dioxide, Ozone, Carbon, etc.
PollutantsDescription
PM 2.5 and PM 10
  • These are extremely fine particulate matter (PM) particles.
  • PM 10 and PM 2.5 are smaller than 10 and 2.5 microns in their diameter, respectively.
  • The PM 2.5 particles can easily bypass the nose and throat and can enter the circulatory system.
  • The particles can also lead to chronic diseases such as asthma, heart attack, bronchitis and other respiratory problems.
  • Byproducts of emissions from factories, vehicular pollution, construction activities and road dust, such particles are not dispersed and stay suspended in the air that we breathe.
Nitrogen Oxides (NOx)
  • It gets in the air from the burning of fuel, with sources including emissions from vehicles and power plants.
  • Short-term exposure to high levels of NO2 can aggravate respiratory diseases like asthma, and lead to other problems such as coughing or difficulty in breathing. Long-term exposure may also contribute to the development of asthma and could increase susceptibility to respiratory infections.
Ozone
  • The surface-level ozone is among the most significant air pollutants. It is formed by the reaction of atmospheric pollutants in the presence of sunlight.
  • Related health hazards include: Chronic Obstructive Pulmonary Disease (COPD), and cardiovascular and respiratory deaths.
Sulfur Dioxide (SO2)
  • The largest source of SO2 in the atmosphere is the burning of fossil fuels by power plants and other industrial facilities. Additional sources are industrial processes and natural sources such as volcanoes.
  • Health hazards include: Damage to the cardiovascular system and respiratory illnesses.
    • SO2 can also react with other compounds to form particulate matter.
    • At high concentrations, gaseous SOx can harm trees and plants by damaging foliage and decreasing growth.
Ammonia (NH3)
  • A broad increase in fertilizer use coupled with large contributions from livestock waste have resulted in the world’s highest concentrations of atmospheric ammonia in India.
  • While gaseous ammonia is a natural part of Earth’s nitrogen cycle, excess ammonia is harmful to plants and reduces air and water quality.
  • In the troposphereammonia gas reacts with nitric and sulfuric acids to form nitrate-containing particles. Those particles contribute to aerosol pollution that is damaging to human health. Ammonia gas can also fall back to Earth and enter lakes, streams and oceans, where it contributes to harmful algal blooms and dead zones with dangerously low oxygen levels
Lead (Pb)
  • It is a naturally occurring toxic metal found in the Earth’s crust.
  • But in increased quantities, exposure to it becomes extremely dangerous to health.
  • Important sources of environmental contamination come from mining, smelting, manufacturing and even recycling activities.
  • Young children are particularly vulnerable to lead poisoning because they absorb four to five times as much ingested lead as adults from a given source.
  • Children who survive severe lead poisoning may be left with permanent intellectual disability and behavioural disorders. At lower levels of exposure that cause no obvious symptoms, lead is now known to produce a spectrum of injury across multiple body systems.
  • There is no known safe level of exposure to lead contamination.
Carbon Monoxide (CO)
  • A toxic, colourless and odourless gas, it is given off when fuel containing carbon, such as wood, coal and petrol, is burned.
  • If CO levels are high enough, a person may become unconscious and die.
  • Long-term exposure has been linked with an increased risk of heart disease.

Source of this article: Indian Express

Environment What are the pollutants in our air