National Ambient Air Quality Standards (NAAQS) 2009 – A Complete Guide & Quiz

Air pollution affects health and the environment. To control it, the Indian government introduced National Ambient Air Quality Standards (NAAQS). These standards were revised in 2009 by the Central Pollution Control Board (CPCB) under the Ministry of Environment, Forest and Climate Change (MoEFCC).

Let’s understand the NAAQS 2009 in simple words.

What are NAAQS?

NAAQS are air quality standards. They define the maximum acceptable limit of pollutants in outdoor air. These limits protect human health and the environment.

Why were the 2009 standards introduced?

Earlier, different areas had different standards. But pollution was spreading fast. So in 2009, the government made uniform standards for all types of areas:

• Industrial
• Residential
• Rural
• Ecologically sensitive areas

The 2009 standards also included new pollutants like PM2.5, ozone, ammonia, benzene, and heavy metals.

Key Pollutants Covered in NAAQS 2009

Here are the 12 key pollutants under NAAQS 2009:

Note: All values are applicable to both general and sensitive areas.

How are these pollutants measured?

The government uses advanced methods to check pollution:

• Gravimetric and Beta Attenuation for PM
• UV Fluorescence for SO₂
• Chemiluminescence for NO₂ and NH₃
• Gas Chromatography for Benzene
• Non-Dispersive Infrared (NDIR) for CO
• ICP or AAS methods for metals like Lead, Nickel, and Arsenic

NAAQS Gazette Notification

Guidelines for the Measurement of
Ambient Air Pollutants

✅ Here’s a printer-friendly version of the full NAAQS 2009 table.
👉 Paste it in front of your study table – glance at it daily!

💥 Do you think you’ve memorized it all?
🎯 Then take this quiz and challenge yourself!

/11

14

---

NAAQS 2009

Download TES Academy for more…

1 / 11

1. Why does NAAQS 2009 specify a lower annual limit for PM2.5 compared to PM10

a. PM10 is less common in urban areas

b. PM10 comes from natural sources only

c. PM2.5 poses a greater health risk

d. PM2.5 is easier to measure accurately

2 / 11

2. What is the annual average limit in Industrial areas for sulfur dioxide (SO₂) under NAAQS 2009?

a. 40 µg/m³

b. 80 µg/m³

c. 50 µg/m³

d. 100 µg/m³

3 / 11

3. The NAAQS 2009 introduced uniform air quality standards across India, eliminating distinctions between industrial and residential areas. Why was this change significant for urban areas like Delhi, which face severe air pollution?

a. It ensured stricter compliance in industrial zones, previously subject to lenient limits, reducing urban pollution.

b. It simplified monitoring by reducing the number of pollutants from 12 to 8, aligning with the AQI.

c. It lowered permissible limits for PM10 only, targeting vehicular emissions in cities like Delhi.

d. It prioritized rural areas over urban centers, redistributing monitoring resources to less polluted regions.

4 / 11

4. A city records a 24-hour average NO₂ concentration of 85 µg/m³, exceeding the NAAQS 2009 limit of 80 µg/m³. Which action would most effectively address this violation in the context of India’s urban pollution sources?

a. Ban biomass burning to reduce secondary NO₂ formation from organic aerosols.

b. Increase coal plant scrubbers to limit NOₓ emissions contributing to urban NO₂.

c. Enforce stricter vehicular emission norms to curb primary NO₂ from diesel exhausts.

d. Expand green cover to absorb NO₂, despite slow impact on traffic-heavy areas.

5 / 11

5. The NAAQS 2009 lowered permissible limits for ozone (O₃) to 100 µg/m³ (8-hour) compared to earlier standards. Why is this significant for India’s developing cities, and what challenge does it pose for compliance?

a. Ozone’s high toxicity demands lower limits, but vehicular emissions make compliance easier.

b. Ozone’s role in crop damage necessitates stricter limits, but monitoring is costly in smaller cities.

c. Lower limits protect against respiratory irritation, but ozone’s short lifespan reduces monitoring needs.

d. Ozone as a primary pollutant requires industrial controls, complicating urban compliance.

6 / 11

6. If a city’s 1-hour ozone (O₃) level is 101 µg/m³, does it meet NAAQS 2009 standards?

a. No, the limit is 100 µg/m³

b. No, the limit is 60 µg/m³

c. No, the limit is 80 µg/m³

d. Yes, the limit is 180 µg/m³

7 / 11

7. What is the 24-hour permissible limit for PM10 under NAAQS 2009?

a. 50 µg/m³

b. 60 µg/m³

c. 40 µg/m³

d. 100 µg/m³

8 / 11

8. The NAAQS 2009 includes ammonia (NH₃) as a pollutant, unlike earlier standards. Why was NH₃ added, and how does its monitoring challenge urban air quality management in India?

a. NH₃ emissions from vehicles dominate urban pollution, necessitating automated monitoring systems.

b. NH₃ forms secondary PM2.5 via reactions with NOₓ and SO₂, but its monitoring is limited by sparse data.

c. NH₃ is a direct respiratory irritant, and its inclusion aligns with WHO’s stricter urban standards.

d. NH₃ contributes to acid rain, and its high urban emissions require simplified monitoring techniques.

9 / 11

9. Why is PM2.5 considered more dangerous than PM10 under NAAQS 2009?

a. PM2.5 is smaller and can enter deep into the lungs

b. PM2.5 is bigger and blocks airways

c. PM10 stays in the air longer

d. PM2.5 comes only from vehicles

10 / 11

10. How often must nitrogen dioxide (NO₂) levels be measured to check compliance with NAAQS 2009 annual standards?

a. Once a month

b. atleast once a day

c. atleast once a week

d. atleast twice a week

11 / 11

11. Under NAAQS 2009, the annual average permissible limit for PM2.5 is 40 µg/m³ in residential areas. If a city’s annual PM2.5 average is 60 µg/m³, which statement best reflects the implications for public health and compliance?

a. The city’s violation is irrelevant, as PM2.5 is monitored only for 24-hour averages under NAAQS.

b. The city meets NAAQS for PM2.5, as the 24-hour limit (60 µg/m³) is not exceeded annually.

c. The city complies with NAAQS, but only if industrial emissions are below 50 µg/m³ annually.

d. The city violates NAAQS, increasing risks of respiratory diseases due to prolonged exposure

Your score is

The average score is 57%

LinkedIn Facebook VKontakte

0%

Restart quiz

Importance of NAAQS in Exams

This topic is highly important in:

• CPCB and state pollution Board exams
• UGC NET Environmental Science
• GATE Ecology and Environmental Science/Eng.