Environmental Engg. 3(2+1)

Lesson-32 ISI standards for air pollutants and their abatements

This chapter deals with the Indian standards for Air quality and their abatements

National Ambient Air Quality Standards (Source: Central Pollution Control Board)

Pollutants	Time Weighted average	Concentration in ambient air
		Industrial areas, Residential, Rural and other areas	Sensitive areas
Sulphur Dioxide (SO2), μg/m3	Annual Average*	50	20
	24 hours**	80	80
Oxides of Nitrogen as (NO2) , μg/m3	Annual Average*	40	30
	24 hours**	80	80
Particulate Matter (RSPM) (size less than 10 microns),  μg/m3	Annual Average*	60	60
	24 hours**	100	100
Particulate Matter (RSPM) (size less than 2.5 microns),  μg/m3	Annual Average*	40	40
	24 hours**	60	60
Ozone (O3), μg/m3	8 hours	100	100
	1 hour	180	180
Lead (Pb), μg/m3	Annual Average*	0.5	0.5
	24 hours**	1.0	1.0
Carbon Monoxide (CO) , mg/m3	8 hours	2	2
	1 hour	4	4
Ammonia, μg/m3	Annual Average*	100	100
	24 hours**	400	400
Benzene	Annual Average*	5	5
Benzo Pyrene – particulate phase only, ng/m3	Annual Average*	1	1
Arsenic, ng/m3	Annual Average*	6	6
Nickel, ng/m3	Annual Average*	20	20

* Annual arithmetic mean of minimum 104 measurements in a year at a particular site taken twice a week 24 hourly at uniform intervals

** 24 hourly or 8 hourly or 1 hourly monitored values, as applicable, shall be compiled with 98 % of the time in a year, 2 % of the time, they may exceed the limits but not on two.

Abatement of air pollution

The air pollution and the resultant air quality can be attributed to emissions from vehicular, industrial and domestic activities. The air quality has been, therefore, an issue of social concern in the backdrop of various developmental activities. The norms for ambient air quality and industry specific emissions have been notified. For control of air pollution, with a view to initiate policy measures and to prepare ambient air quality management plans, 321 Air Quality Monitoring Stations are operational covering twenty five States and four Union Territories.

The CPCB has evolved a format for preparation of action plans, which has been circulated to all State Pollution Control Boards/Committees. The action plans emphasize identification of sources of air pollution, assessment of pollution load and adoption of abatement measures for identified sources. Setting up interdepartmental task force for implementation of city specific action plan has also been suggested.

In order to control vehicular pollution, a road map has been adopted as per the schedule proposed in Auto Fuel Policy, which includes use of cleaner fuels, automobile technologies and enforcement measures for in use vehicles through improved Pollution Under control (PUC) certification system. As per the Auto Fuel Policy, Bharat Stage-II norms for new vehicles have been introduced through out the country from first April, 2005. However, EURO-III equivalent emission norms for all new vehicles, except 2-3 wheelers, have been introduced in 11 major cities from April 1, 2005. To meet Bharat Stage-II, EURO-III and EUROIV emission norms, matching quality of petrol and diesel is being made available.