- Why in news?
- The presence of Particulate matter is contributing more to the pollution scenario.
- What is particulate matter?
- Particulate matter (PM), also called particle pollution is a mixture of solid particles and liquid droplets found in the air.
- Particles can be suspended in the air for long periods of time.
- Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye.
- Others are so small that they can only be detected using an electron microscope.
- Particle pollution includes:
- PM10 : inhalable particles, with diameters that are generally 10 micrometers and smaller; and
- 5: fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller.
- Sources of PM:
- Some are emitted directly from a source, such as construction sites, unpaved roads, fields, smokestacks or fires.
- Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles.
- They are indirectly formed when gases from burning fuels react with sunlight and water vapor.
- Harmful Effects of PM:
- They are so small that they can be inhaled and cause serious health problems.
- Some particles less than 10 micrometers in diameter can get deep into lungs and some may even get into the bloodstream.
- Fine particles are also the main cause of reduced visibility (haze).
- According to a study, an increase in PM2.5 by one microgram per cubic metre reduces life expectancy by three weeks.
