Air Pollution: IAQ, SBS & AQI
1. Indoor Air Quality (IAQ)
Overview: Indoor air quality (IAQ) refers to the quality of the air within buildings and structures. Poor IAQ can affect the health, comfort, and well-being of occupants.
Indoor Air Pollution in Developing Countries
📝 Exam Focus: In less developed countries, indoor exposure to hazardous air pollutants is much severe.
📝 Exam Focus: Traditional cooking methods often involve fuels such as coal, wood, animal dung, kerosene etc.
This "household air pollution" affects approximately 3 billion people, mainly women and children.
Common Indoor Air Pollutants
- Secondhand Tobacco Smoke
- Indoor Combustion Pollutants
- Radon, Asbestos Fibers, and Carbon Monoxide
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Volatile Organic Compounds (VOCs):
📝 Exam Focus: Concentration of Formaldehyde in indoor environment can be thousand times higher than outdoor environment.📝 Exam Focus: Formaldehyde is a known carcinogen.
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Molds and Allergens:
📝 Exam Focus: Allergens are substances that activate the immune system.📝 Exam Focus: Concentration of allergens in an indoor environment can be thousand times higher than in the air outside.
2. Sick Building Syndrome (SBS)
📝 Exam Focus: Sick Building Syndrome (SBS) is a condition of human health due to indoor air pollution.
📝 Exam Focus: Polluted indoor air causes Sick Building Syndrome (SBS).
📝 Exam Focus: Some people suffer from what is called Sick Building Syndrome (SBS).
Symptoms include headaches, dizziness, fatigue, and eye/nose/throat irritation. Symptoms typically worsen inside the building and improve upon leaving.
Causes
SBS is primarily associated with poor indoor air quality due to factors such as:
- Inadequate ventilation
- Chemical contaminants from indoor sources (adhesives, upholstery, carpeting, copy machines).
- Biological contaminants (mold, bacteria, pollen).
- Other factors like inadequate temperature, humidity, or lighting.
3. Air Quality Index (AQI)
Exam Focus: Air Quality Index (AQI) is used to report to the public an overall assessment of a given day's air quality.
📝 Exam Focus: The AQI typically includes multiple key pollutants: PM10, PM2.5, NO₂, SO₂, CO, O₃, and sometimes Lead (Pb).
Pollutants Monitored
📝 Exam Focus: TSP (Total Suspended Particles) and PM10 are used in calculation.
📝 Exam Focus: NO₂ (Nitrogen dioxide) is included while estimating AQI.
AQI Categories and Health Impact
0-50 Good (Air quality is satisfactory)
51-100 Moderate (Acceptable for most people)
101-150 Unhealthy for Sensitive Groups
151-200 Unhealthy (Everyone may experience health effects)
201-300 Very Unhealthy (Health alert)
301-500 Hazardous (Emergency conditions)
Key Pollutants Monitored
💨 PM10 & PM2.5
🏭 NO₂
🌫️ SO₂
🚗 CO
☀️ O₃
⚗️ Pb (Lead)
4. India's National Air Quality Index (NAQI)
🇮🇳 Launched: September 17, 2014 (Swachh Bharat Abhiyan)
Goal: One Number, One Color, One Description.
The 8 Pollutants in NAQI
1. PM10
2. PM2.5
3. NO₂
4. SO₂
5. CO
6. O₃
7. NH₃ (Ammonia)
8. Pb (Lead)
📝 Exam Focus: Sulphur dioxide pollutants are included in the Air Quality Index in India.