Which of the following pollutants was not included in the original National Ambient Air Quality Standards (1982) but was added later to the 12 parameters?
- ASulfur Dioxide (SO2)
- BNitrogen Dioxide (NO2)
- CBenzeneCorrect
- DSuspended Particulate Matter (SPM)
Solution
Concept
Historical evolution and expansion of NAAQS pollutants
Formula
NONE
Step-by-step solution
1. Original 1982 standards monitored conventional pollutants: SO2, NO2, SPM, and CO. 2. The revised NAAQS 2009 expanded monitoring to 12 parameters. 3. Newly introduced hazardous air pollutants include Benzene, Benzo(a)pyrene, Arsenic, and Nickel. 4. Among the options, Benzene is the pollutant added in the revised standards. Answer: C
Explanation
The original NAAQS notified by CPCB in 1982 (and amended in 1994) covered SO2, NO2, SPM, RPM/PM10, CO, and Lead. In the revised 2009 NAAQS notification, CPCB expanded the scope to 12 parameters, adding volatile organic compounds and air toxics including Benzene (C6H6), Benzo(a)pyrene, Ozone (O3), Ammonia (NH3), Arsenic (As), and Nickel (Ni).
Why the other options are wrong
A) SO2 was among the first parameters monitored in the 1982 standards. B) NO2 was included in the 1982 standards. D) SPM was the primary particulate parameter in 1982 (later phased out for PM10 and PM2.5 in 2009).
Shortcut
Benzene, Benzo(a)pyrene, O3, NH3, As, Ni were added in NAAQS 2009; SO2, NO2, SPM were in 1982.
Common mistake
Selecting SO2 or NO2, which were the founding criteria pollutants present since 1982.
Correct answer: C) Benzene