Minnesota Radon Mitigation
Professional Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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1. What is the primary purpose of a radon mitigation system?
A. Increase indoor humidity
B. Reduce airborne dust
C. Reduce indoor radon concentrations
D. Increase ventilation only
Answer: C. Reduce indoor radon concentrations
Rationale: Radon mitigation systems are designed specifically to lower
radon gas levels inside buildings to reduce health risks associated with
long-term exposure.
2. Radon is produced by the natural decay of:
,A. Carbon
B. Nitrogen
C. Uranium
D. Oxygen
Answer: C. Uranium
Rationale: Radon is a radioactive gas formed during the decay process of
uranium found naturally in soil, rock, and groundwater.
3. Which type of radon mitigation system is most commonly used in
homes with basements?
A. Heat recovery ventilation
B. Crawlspace pressurization
C. Sub-slab depressurization
D. Air purification
Answer: C. Sub-slab depressurization
Rationale: Sub-slab depressurization creates negative pressure beneath
the foundation to prevent radon from entering the building.
4. The EPA action level for radon is:
A. 2.0 pCi/L
B. 3.0 pCi/L
,C. 4.0 pCi/L
D. 5.0 pCi/L
Answer: C. 4.0 pCi/L
Rationale: The Environmental Protection Agency recommends mitigation
when indoor radon levels are 4.0 pCi/L or higher.
5. Which foundation type commonly requires sub-membrane
depressurization?
A. Slab-on-grade
B. Basement
C. Crawlspace
D. Pier foundation
Answer: C. Crawlspace
Rationale: Sub-membrane depressurization is installed beneath a plastic
membrane covering exposed soil in crawlspaces.
6. What unit is commonly used to measure radon concentration?
A. ppm
B. mg/L
C. Bq/cm³
D. pCi/L
, Answer: D. pCi/L
Rationale: Picocuries per liter (pCi/L) is the standard unit used in the
United States.
7. A mitigation fan should generally be located:
A. In occupied spaces
B. In bedrooms
C. Outside conditioned living areas
D. In kitchens
Answer: C. Outside conditioned living areas
Rationale: Fans are installed in attics, garages, or outside the building
envelope to prevent radon leakage indoors.
8. Which gas is colorless, odorless, and radioactive?
A. Carbon monoxide
B. Methane
C. Nitrogen
D. Radon
Answer: D. Radon
Rationale: Radon cannot be detected by human senses and requires testing
equipment for identification.
Professional Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a radon mitigation system?
A. Increase indoor humidity
B. Reduce airborne dust
C. Reduce indoor radon concentrations
D. Increase ventilation only
Answer: C. Reduce indoor radon concentrations
Rationale: Radon mitigation systems are designed specifically to lower
radon gas levels inside buildings to reduce health risks associated with
long-term exposure.
2. Radon is produced by the natural decay of:
,A. Carbon
B. Nitrogen
C. Uranium
D. Oxygen
Answer: C. Uranium
Rationale: Radon is a radioactive gas formed during the decay process of
uranium found naturally in soil, rock, and groundwater.
3. Which type of radon mitigation system is most commonly used in
homes with basements?
A. Heat recovery ventilation
B. Crawlspace pressurization
C. Sub-slab depressurization
D. Air purification
Answer: C. Sub-slab depressurization
Rationale: Sub-slab depressurization creates negative pressure beneath
the foundation to prevent radon from entering the building.
4. The EPA action level for radon is:
A. 2.0 pCi/L
B. 3.0 pCi/L
,C. 4.0 pCi/L
D. 5.0 pCi/L
Answer: C. 4.0 pCi/L
Rationale: The Environmental Protection Agency recommends mitigation
when indoor radon levels are 4.0 pCi/L or higher.
5. Which foundation type commonly requires sub-membrane
depressurization?
A. Slab-on-grade
B. Basement
C. Crawlspace
D. Pier foundation
Answer: C. Crawlspace
Rationale: Sub-membrane depressurization is installed beneath a plastic
membrane covering exposed soil in crawlspaces.
6. What unit is commonly used to measure radon concentration?
A. ppm
B. mg/L
C. Bq/cm³
D. pCi/L
, Answer: D. pCi/L
Rationale: Picocuries per liter (pCi/L) is the standard unit used in the
United States.
7. A mitigation fan should generally be located:
A. In occupied spaces
B. In bedrooms
C. Outside conditioned living areas
D. In kitchens
Answer: C. Outside conditioned living areas
Rationale: Fans are installed in attics, garages, or outside the building
envelope to prevent radon leakage indoors.
8. Which gas is colorless, odorless, and radioactive?
A. Carbon monoxide
B. Methane
C. Nitrogen
D. Radon
Answer: D. Radon
Rationale: Radon cannot be detected by human senses and requires testing
equipment for identification.
