Air Quality Monitoring

Context (TH): Delhi’s air quality plunged to ‘very poor’, with a thick layer of haze blanketing the national capital.

Air quality monitoring is the process of measuring various pollutants present in the air.
It can be used to identify pollution sources, monitor climate change, or support research and development.

Read in detail about Air Pollution.

Monitoring Air Quality in India: Measures

The Central Pollution Control Board (CPCB) has been executing a nationwide ambient air quality monitoring programme known as National Air Quality Monitoring Programme (NAMP).
NAMP network comprises 800+ operating stations covering 344 cities/towns in 28 states and 6 UTs.
NAMP is undertaken to determine the status and trends of ambient air quality, ascertain the compliance of NAAQS, identify non-attainment cities, etc.
Under NAMP, Sulphur Dioxide (SO2), Oxides of Nitrogen (NO2), Respirable Suspended Particulate Matter (PM10) and Fine Particulate Matter (PM2.5) are regularly monitored.
The monitoring of wind speed and direction, relative humidity and temperature were also integrated with the monitoring of air quality.

NAAQS are standards for air quality set up by CPCB in 2009.
The CPCB has been conferred this power by the Air (Prevention & Control of Pollution) Act, 1981.
NAAQS consists of twelve pollutants.

National Ambient Air Quality Standards, as of 2009
Pollutants (12)	Time Weighted Average	Concentration in Ambient Air
Pollutants (12)	Time Weighted Average	Industrial, Residential, Rural & Other Area	Ecologically Sensitive Area (notified by GOI)
SO₂, μg/m³	Annual	50	20
SO₂, μg/m³	24 hours	80	80
NO₂, μg/m³	Annual	40	30
NO₂, μg/m³	24 hours	80	80
PM₁₀, μg/m³	Annual	60	60
PM₁₀, μg/m³	24 hours	100	100
PM₂_.₅, μg/m³	Annual	40	40
PM₂_.₅, μg/m³	24 hours	60	60
O₃, μg/m³	8 hours	100	100
O₃, μg/m³	1 hour	180	180
Lead (Pb), μg/m³	Annual	0.50	0.50
Lead (Pb), μg/m³	24 hours	1	1
CO, mg/m³	8 hours	2	2
CO, mg/m³	1 hour	4	4
Ammonia (NH₃), μg/m³	Annual	100	100
Ammonia (NH₃), μg/m³	24 hours	400	400
Benzene, μg/m³	Annual	5	5
Benzopyrene, μg/m³	Annual	1	1
Arsenic (As), ng/m³	Annual	6	6

Nickel (Ni), ng/m³

Annual

AQI was launched in 2014 with an outline ‘One Number – One Color – One Description’ for the common man to judge the air quality within his vicinity.
It has been developed by Central Pollution Control Board (CPCB).

For greater metropolitan cities of India to provide location specific information on air quality in near real time.
Introduced by Ministry of Earth Sciences. Developed by Indian Institute of Tropical Meteorology, Pune
Pollutants measured: PM2.5, PM10, Ozone, Carbon Monoxide (CO), Nitrogen Oxides (NOx), Sulfur Dioxide (SO2), Benzene, Toluene, Xylene, and Mercury.

Commissoned by Indian Army at its Eastern Command Headquarters in Fort William Military Station, Kolkata, West Bengal.
To monitor ambient air quality on real- time basis.

WHO has released an updated version of the Global Air Quality Guidelines (AQGs).
The guidelines consider how air pollution damages human health at even lower concentrations.

The air quality database is a compilation of data on air quality and the concentrations of PM.
It compiles ground measurements of annual mean concentrations of NO2, PM10 and PM2.5.
It was started in 2011 and has since then been periodically updated.
Its update in 2023 is the sixth update to the database.

For the first time, in the fifth update, the database contains the ground measurements of nitrogen dioxide, which the WHO calls “a common urban pollutant and precursor of PM and ozone.”