PM 2.5 & NITROGEN DIOXIDE

Subject : Environment

Context : PM2.5 and NO2 contributing to the spread and virulence of SARS-CoV-2 infections, says Health Minister.

Concept :

PM 2.5

5 refers to particles that have diameter less than 2.5 micrometres (more than 100 times thinner than a human hair) and remain suspended for longer.
These particles are formed as a result of burning fuel and chemical reactions that take place in the atmosphere. Natural processes such as forest fires also contribute to PM2.5 in the air. These particles are also the primary reason for occurrence of smog.

Nitrogen oxide (NOx)

NOx is a generic term for the various nitrogen oxides produced during combustion.
They are produced mainly in internal combustion engines and coal-burning power plants.
They are also produced naturally by lightning.
Oxygen and nitrogen do not react at ambient temperatures. But at high temperatures, they produce various oxides of nitrogen. Such temperatures arise inside an internal combustion engine or a power station boiler.
Agricultural fertilisation and the use of nitrogen-fixing plants also contribute to atmospheric NOx, by promoting nitrogen fixation by microorganisms.