AQS AQS Indoor Air Quality 1 — Questions and Answers
Question 1: Which indoor air pollutant is classified as the second leading cause of lung cancer in the United States?
- Carbon monoxide
- Radon (Correct answer)
- Formaldehyde
- Asbestos
Correct answer: Radon
Radon, a naturally occurring radioactive gas that seeps from soil and rock, is the second leading cause of lung cancer in the US after cigarette smoking.
Question 2: The EPA's action level for radon in indoor air is:
- 2 pCi/L
- 4 pCi/L (Correct answer)
- 10 pCi/L
- 0.4 pCi/L
Correct answer: 4 pCi/L
The EPA recommends mitigating radon when indoor concentrations reach or exceed 4 picocuries per liter (pCi/L) of air.
Question 3: What is the primary health concern associated with indoor carbon monoxide (CO) exposure?
- Skin irritation
- Carboxyhemoglobin formation preventing oxygen transport (Correct answer)
- Lung fibrosis
- Neurological cancer risk
Correct answer: Carboxyhemoglobin formation preventing oxygen transport
CO binds to hemoglobin with ~250x greater affinity than oxygen, forming carboxyhemoglobin and reducing blood's oxygen-carrying capacity, causing hypoxia and potentially death.
Question 4: ASHRAE Standard 62.1 primarily governs:
- Outdoor ambient air quality limits
- Ventilation rates for acceptable indoor air quality in commercial buildings (Correct answer)
- Radon mitigation system design
- Asbestos abatement procedures
Correct answer: Ventilation rates for acceptable indoor air quality in commercial buildings
ASHRAE 62.1 specifies minimum ventilation rates and indoor air quality requirements for commercial, institutional, and high-rise residential buildings.
Question 5: Sick Building Syndrome (SBS) differs from Building-Related Illness (BRI) in that:
- SBS affects only industrial buildings
- SBS symptoms cannot be attributed to a specific identifiable cause, while BRI has a diagnosable cause (Correct answer)
- SBS only involves chemical exposures
- BRI does not involve occupants leaving the building
Correct answer: SBS symptoms cannot be attributed to a specific identifiable cause, while BRI has a diagnosable cause
SBS describes nonspecific symptoms (headache, irritation) that improve upon leaving the building without an identifiable cause, whereas BRI involves clinically diagnosed illness linked to a specific indoor exposure.
Question 6: Which chemical is commonly off-gassed by new furniture, carpets, and pressed-wood products and classified as a probable human carcinogen?
- Benzene
- Formaldehyde (Correct answer)
- Trichloroethylene
- Xylene
Correct answer: Formaldehyde
Formaldehyde is released from urea-formaldehyde resins in pressed wood, adhesives, and textiles; IARC classifies it as a Group 1 human carcinogen.
AQS AQS Indoor Air Quality 1
Which indoor air pollutant is classified as the second leading cause of lung cancer in the United States?