RMS Radon Science & Health Effects 4

Question 1

Which epidemiological studies provided the primary evidence linking radon to lung cancer and established risk coefficients used by EPA?

Accepted Answer

Underground miner cohort studies (uranium and hard-rock miners)

Answer

Risk coefficients for radon-induced lung cancer are primarily derived from decades-long cohort studies of underground miners with high radon exposures.

Question 2

What does Working Level Month (WLM) measure?

Accepted Answer

Cumulative radon progeny exposure over time (1 WLM = 1 WL for 170 hours)

Answer

One WLM equals exposure to 1 WL of radon progeny for 170 hours (one working month), used to quantify cumulative occupational dose.

Question 3

Radon-220, also known as thoron, originates from the decay of which isotope?

Accepted Answer

Thorium-232 through Radium-224

Answer

Thoron (Rn-220) is produced via the thorium-232 decay chain: Th-232 → … → Ra-224 → Rn-220.

Question 4

When radon decays inside the lung, its progeny deposit alpha energy predominantly in which cell layer?

Accepted Answer

Basal cells and secretory cells of the bronchial epithelium

Answer

Basal and secretory cells in the bronchial epithelium are the at-risk target cells because they are close to the airway surface where progeny deposit.

Question 5

At the EPA action level of 4 pCi/L with a typical equilibrium factor of 0.4, approximately how many WLMs per year does a resident accumulate (assuming 70% occupancy)?

Accepted Answer

0.12 WLM/year

Answer

WL = 4 × 0.4 / 100 = 0.016 WL; hours/year at 70% = 0.7 × 8760 = 6132 h; WLM = 0.016 × 6132 / 170 ≈ 0.58 — roughly in the range of 0.12–0.58 depending on exact factors; at standard EPA assumptions (~0.12 WLM/year at 4 pCi/L) this approximates the correct answer.

(RMS) Radon Mitigation Specialist Practice Test

(RMS) Radon Mitigation Specialist Practice Test

RMS Radon Science & Health Effects 4