Radon Deck

Question 1

Occupational limit for radon exposure in the United States is:

Answer 1

4 WLM/year. One working level-month produces about one rem CEDE.

Question 2

The ‘unattached fraction’ discussed when evaluating radon concentrations:

Answer 2

Used by the EPA to estimate the amount of actual radon progeny present. Sometimes called the equilibrium factor - typical factor starts at 0.5

Question 3

Radon gas can be found in which naturally occurring decay chain(s)?

Answer 3

All of them. Thorium (Rn-220), Uranium (Rn-222), and Actinium (Rn-219)

Question 4

Definition of ‘Working Level’

Answer 4

Measurement of atmospheric concentration of radon progeny. Any combination of short lived radon daughters in 1L of air that will result in the ultimate emission of 1.3E5 MeV of alpha energy.

Question 5

The Working Level used in Canada and the USA as a unit of radon decay is:

Answer 5

a liter of air with the emission of 1.3E5 MeV alpha. 1 WL is equal to 100 pCi/L air of Rn-222 in equilibrium with its daughters. The DAC for Rn-222 is 1/3 the working level.

Question 6

Radon daughters inhaled during uranium mining are normally deposited in:

Answer 6

The lungs

Question 7

Suggested action level for Radon concentrations in homes

Answer 7

4 pCi/L

Question 8

What report is titled “The Health Effects of Exposure to Indoor Radon,” ?

Answer 8

BEIR VI 1999

Question 9

Working Level Month (WLM) is

Answer 9

the exposure resulting from inhalation of air with a 1-WL concentration for a period of 1 working month (170 hours)

Question 10

What is the Critical Organ and by what mechanism is the Critical Organ exposed to Radon?Rev. 1

Answer 10

Critical Organ is the lungs. Excess cancers in urainum minors have been observed in the Bronchial Epithelium.

Question 11

If 1,000 people who never smoked were exposed to this level over a lifetime about how many people could get lung cancer if exposed to a concentration of 4 pCi/L?Rev. 1

Answer 11

23 Reference: EPA Assessment of Risks from Radon in Homes

Question 12

Explain why the “oxygen effect” is or is not significant with radon exposureRev. 1

Answer 12

The effect is not signification for radon exposure because alpha radiation released from radon is high-LET radiation. The oxygen effect describes the enhanced biological damage that occurs in the cells when dissolved oxygen is present as a result of the formation of long-lived free radicals. This is more significant in low-LET radiation events as they are likely to produce more free-radicals.