US Standards			W.H.O. Standards
	Standard Value	Standard Type
Carbon Monoxide (CO)
8-Hour Average	9 ppm	(10 mg/m3)**	Primary	30 mg/m3
1-Hour Average	35 ppm	(40 mg/m3)**	Primary	10 mg/m3
Nitrogen Dioxide
Annual Arithmetic Mean	0.053 ppm	(100 ug/m3)**	Primary & Secondary	30 mg/m3
24-Hour Average				150 mg/m3
Ozone (O3)
8-Hour Average	0.08 ppm	(157 ug/m3)**	Primary & Secondary
1-Hour Average	0.12 ppm	(235 ug/m3)**	Primary & Secondary	150-200 ug/m3
Lead (Pb)
Quarterly Average		1.5 ug/m3	Primary & Secondary
24-Hour				1.5 ug/m3

* The ozone1-hour standard applies only to areas that were designated no attainment when the ozone-8 hour standards was adopted in July 1997. This provision allow a smooth, legal, and practical transition to the 8-hour standard
** Parenthetical value is an approximately equivalent concentration

	US Standards			W.H.O. Standards
	Standard Value	Standard Type
Particulate <10 micrometers(PM-10)
Annual Arithmetic Mean		50 ug/m3	Primary & Secondary	60-90ug/m3
24-Hour Average		150 ug/m3	Primary & Secondary	150-230 ug/m3
Particulate <2.5 micrometers(PM-2.5)
Annual Arithmetic Mean		15 ug/m3	Primary & Secondary
24-Hour Average		65 ug/m3	Primary & Secondary
Sulfur Dioxide (SO2)
Annual Arithmetic Mean	0.03 ppm	(80 ug/m3)**	Primary	40-60ug/m3
24-Hour Average	0.14 ppm	(365 ug/m3)**	Primary	100-150 ug/m3
3-Hour Average	0.50 ppm	(1300 ug/m3)**	Secondary

*The ozone1-hour standard applies only to areas that were designated no attainment when the ozone-8 hour standards was adopted in July 1997. This provision allow a smooth, legal, and practical transition to the 8-hour standards
** Parenthetical value is an approximately equivalent concentration

Time Weighted Average	Industrial Areas		Residential Rural & Other Areas		Sensitive Areas		Method of Measurement
	ug/m3	ppm	ug/m3	ppm	ug/m3	ppm
Sulphur Dioxide (SO2)
Annual *	80	0.0302	60	0.0226	15	0.00567	-Improved West and Geake  Method -Ultraviolet Fluorescence
24 Hours **	120	0.453	80	0.0302	30	0.0113
Oxide Nitrogen as (NO2)
Annual *	80	0.042	60	0.0315	15	0.0078	-Jacob & Hochheiser  Modiifed (Na Arsenite Method) -Gas Phase   Chemiluminescense
24 Hours **	120	0.0631	80	0.042	30	0.0157
Suspended Particulate Matter (SPM)
Annual *	360	--	140	--	70		-High Volume Sampling  (Average flow rate note less  than 1.1 m3 minute)
24 Hours **	500	--	200	--	100	--

Time Weighted Average	Industrial Areas		Residential Rural & Other Areas		Sensitive Areas		Method of Measurement
	ug/m3	ppm	ug/m3	ppm	ug/m3	ppm
Respirable Particulate Matter (RSPM)
Annual *	120	--	60	--	50	--	-Respirable particulate -Matter Sampler
24 Hours **	150	--	100	--	75	--
Lead (Pb)
Annual *	1.0	0.00116	0.75	0.00087	0.50	0.00058	-ASS Method after Sampling using -EPM 2000 or Equivalent Filter Paper
24 Hours **	1.5	0.00174	1.00	0.00116	0.75	0.00087
Carbon Monoxide (CO)
8 Hours	5.0	2.751	2.0	1.1	1.0	0.550	-Non depressive IR -Spectroscopy
1 Hours	--	5.502	4.0	2.2	2.0	1.1

Annual Arithmetic mean of minimum 104 measurements in a year taken twice a week 24 hourly at uniform interval ** 24Hourly /8 Hourly values should be met 98% of the time in a year. However, 2% of the time, it may exceed but not on two consecutive days

Note : NAAQS –The levels of air quality with an adequate margin of safety, to protect the public health, vegetation and property. Whenever and wherever two consecutive values exceeds the limit specified above for the respective category it would be considered adequate reason to institute regular/continuous monitoring and further investigations