Air Quality Assessment MCQs January 8, 2026August 13, 2024 by u930973931_answers 40 min Score: 0 Attempted: 0/40 Subscribe 1. Which of the following is a primary pollutant? (A) Ozone (B) Sulfur dioxide (C) Smog (D) Peroxyacetyl nitrate 2. The Air Quality Index (AQI) is used to measure: (A) Air pollution levels (B) Soil contamination (C) Water quality (D) Noise pollution 3. Which gas is the main contributor to the greenhouse effect? (A) Nitrogen (B) Oxygen (C) Methane (D) Carbon dioxide 4. The Clean Air Act was enacted in which year in the United States? (A) 1990 (B) 1965 (C) 1980 (D) 1970 5. PM2.5 refers to particulate matter that is less than how many micrometers in diameter? (A) 2.5 micrometers (B) 5 micrometers (C) 10 micrometers (D) 1 micrometer 6. Which of the following is a secondary pollutant? (A) Ozone (B) Nitric oxide (C) Carbon monoxide (D) Lead 7. Ground-level ozone is formed by the reaction of: (A) Nitrogen oxides and volatile organic compounds (B) Carbon monoxide and sulfur dioxide (C) Lead and particulate matter (D) Ozone and nitrogen dioxide 8. Which of the following is an indoor air pollutant? (A) Sulfur dioxide (B) Ozone (C) Nitric oxide (D) Radon 9. The term “smog” is derived from which two words? (A) Sulfur and fog (B) Soot and smog (C) Smoke and fog (D) Smoke and dust 10. Which pollutant is primarily responsible for acid rain? (A) Nitrogen dioxide (B) Carbon monoxide (C) Ozone (D) Sulfur dioxide 11. Which of the following methods is commonly used for measuring particulate matter in the air? (A) Gas chromatography (B) Spectrophotometry (C) Gravimetric analysis (D) Colorimetry 12. Which of the following pollutants is monitored under the National Ambient Air Quality Standards (NAAQS)? (A) Lead (B) Radon (C) Water vapor (D) Chlorofluorocarbons (CFCs) 13. Which device is commonly used to control particulate emissions from industrial sources? (A) Scrubber (B) Catalytic converter (C) Electrostatic precipitator (D) Baghouse filter 14. The “Greenhouse Gas Protocol” is an international accounting tool for: (A) Water pollution (B) Greenhouse gas emissions (C) Air pollution (D) Noise pollution 15. Which of the following is a natural source of air pollution? (A) Power plant emissions (B) Automobile exhaust (C) Industrial emissions (D) Volcanic eruptions 16. What is the main component of natural gas that contributes to greenhouse gas emissions? (A) Methane (B) Butane (C) Propane (D) Ethane 17. Which of the following is NOT a major greenhouse gas? (A) Carbon dioxide (B) Methane (C) Nitrogen (D) Water vapor 18. The “Montreal Protocol” is an international treaty designed to protect the ozone layer by phasing out the production of: (A) Chlorofluorocarbons (CFCs) (B) Nitrous oxide (C) Carbon dioxide (D) Sulfur dioxide 19. What is the maximum allowable concentration of carbon monoxide (CO) in the air, according to WHO guidelines, for an 8-hour exposure? (A) 10 ppm (B) 9 ppm (C) 35 ppm (D) 50 ppm 20. The term “PM10” refers to particulate matter with a diameter less than: (A) 10 micrometers (B) 5 micrometers (C) 2.5 micrometers (D) 1 micrometer 21. Which of the following pollutants can cause respiratory problems, particularly in children and the elderly? (A) Argon (B) Nitrogen (C) Oxygen (D) Ozone 22. The term “bioaerosols” refers to: (A) Volatile organic compounds (B) Particles of biological origin (C) Industrial emissions (D) Gaseous pollutants 23. Which of the following gases is a major component of photochemical smog? (A) Carbon dioxide (B) Methane (C) Ozone (D) Nitrous oxide 24. What is the primary source of sulfur dioxide in the atmosphere? (A) Automobile exhaust (B) Power plants (C) Forest fires (D) Residential heating 25. Which of the following methods is used to control nitrogen oxides (NOx) emissions from industrial sources? (A) Flue gas desulfurization (B) Carbon sequestration (C) Electrostatic precipitation (D) Selective catalytic reduction 26. Which of the following is considered a greenhouse gas? (A) Oxygen (B) Argon (C) Carbon dioxide (D) Nitrogen 27. Which of the following is the main source of indoor air pollution in developing countries? (A) Smoking (B) Combustion of solid fuels (C) Volatile organic compounds from paint (D) Radon 28. Which of the following is the major source of carbon monoxide in urban areas? (A) Automobile exhaust (B) Industrial emissions (C) Residential heating (D) Forest fires 29. Which of the following pollutants is mainly responsible for the depletion of the ozone layer? (A) Nitric oxide (B) Chlorofluorocarbons (CFCs) (C) Carbon monoxide (D) Sulfur dioxide 30. What does the acronym “VOC” stand for in the context of air pollution? (A) Volatile Oxygen Compounds (B) Variable Organic Chemicals (C) Volatile Organic Compounds (D) Voluminous Organic Carbon 31. The term “thermal inversion” refers to: (A) An increase in temperature with altitude (B) A decrease in temperature with altitude (C) The mixing of warm and cold air masses (D) The dispersion of pollutants 32. Which of the following pollutants can cause damage to the nervous system when inhaled at high concentrations? (A) Lead (B) Carbon dioxide (C) Oxygen (D) Nitrogen 33. Which of the following is a major anthropogenic source of methane emissions? (A) Livestock digestion (B) Automobile exhaust (C) Volcanoes (D) Forest fires 34. Which of the following technologies is commonly used to monitor air quality in real-time? (A) Gas chromatography (B) Mass spectrometry (C) Gravimetric analysis (D) Laser scattering 35. What is the primary component of smog that irritates the eyes and throat? (A) Nitrogen dioxide (B) Ozone (C) Carbon monoxide (D) Lead 36. The “Kyoto Protocol” is an international agreement aimed at reducing: (A) Ozone depletion (B) Greenhouse gas emissions (C) Airborne particulate matter (D) Acid rain 37. What is the main source of volatile organic compounds (VOCs) in the atmosphere? (A) Natural gas (B) Paints and solvents (C) Forest fires (D) Automobile exhaust 38. The term “acid rain” refers to precipitation with a pH lower than: (A) 7 (B) 6.5 (C) 4.5 (D) 5.6 39. Which of the following pollutants is the primary cause of respiratory illnesses in urban areas? (A) Ozone (B) Carbon dioxide (C) Methane (D) Sulfur dioxide 40. Which of the following is a consequence of air pollution on human health? (A) Reduced immunity (B) Improved lung function (C) Increased energy levels (D) Enhanced cognitive function