Q. Which of the following pollutants are listed under the National Ambient Air Quality Standards (NAAQS)?

1. Benzene
2. Arsenic
3. Toluene
4. PM 2.5
5. Ozone

Select the correct answer using the codes given below:
Answer: Only 1, 2, 4 & 5
Notes: Under NAAQS, the notified pollutants include PM10, PM2.5, SO2, NO2, CO, NH3, Ozone, Lead, Benzene, Benzo(a)Pyrene, Arsenic, and Nickel. Toluene is not covered under NAAQS, whereas Benzene, Arsenic, PM2.5, and Ozone are explicitly mentioned. Therefore, the correct combination is 1, 2, 4, and 5 only.