1. Lesson 6 What are the testing strategies for radon?

2. Slide 6-1 EPA goals Are timely Are simple Are cost effective Protect human health Help people make decisions about radon reduction that

3. Slide 6-2 Importance of reliable measurement Helps property owners decide whether to mitigate May be part of price negotiations in real estate transactions What should I do to protect my family? If the mitigation system on our new home will cost $1500, will the seller reduce the asking price?

4. Slide 6-3 Measures radon levels during brief test period Often used in real estate transactions Devices include –Charcoal canisters –Charcoal liquid scintillation detectors –Electret ion chamber devices –Continuous monitors Length of test Short-term test 91-365 days Provides more information about a home’s year- round average radon level Devices include –Alpha track devices –Electret ion chamber devices Long-term test 2-90 days

5. Slide 6-4 Length of test Both types of test can provide accurate results Both types of test usually lead to same decisions about mitigation

6. Slide 6-5 General testing process (not related to sale of a home) Step 1Conduct a short-term test Step 2Determine what follow-up strategy is needed Step 3Conduct any needed follow-up test Step 4Examine results of all tests to determine what to advise the homeowner

7. Slide 6-6 General testing strategies Determine what follow-up strategy is needed Follow-up depends on the first test result 0–under 4 pCi/L (0–under 0.02 WL) 4–under 10 pCi/L (0.02–under 0.05 WL) 10 pCi/L and above (0.05 WL and above)

8. Slide 6-7 General testing Advise the owner to test again in the future, especially if An unused lower level becomes used as a living space Structural changes are made Changes in the HVAC system are made If the first test result is 0–under 4 pCi/L You do not have to conduct a follow-up test now

9. Slide 6-8 General testing If the first test result is 4 pCi/L or more, conduct a follow-up test 4–under 10 pCi/L10 pCi/L and above

10. Slide 6-9 General testing If the first test result is 4 pCi/L or more but under 10 pCi/L Conduct a follow-up short-term test or long-term test With another short-term test, average the results of the first and follow-up tests With a long-term test, use the long-term results If the average is under 4 pCi/L, advise the owner to test again in the future If the average is 4 pCi/L or more, advise the owner to mitigate If the result is under 4 pCi/L, advise the owner to test again in the future If the result is 4 pCi/L or more, advise the owner to mitigate

11. Slide 6-10 General testing If the first test result is 10 pCi/L or more Conduct a follow-up short-term test Average the results of the first and follow-up tests If the average is under 4 pCi/L, advise the owner to test again in the future If the average is 4 pCi/L or more, advise the owner to mitigate

12. Slide 6-11 Example First short-term test result = 5.4 pCi/L –Advise follow-up test –Either short-term or long-term test Second short-term test result = 3.8 pCi/L Average = 4.6 pCi/L –Recommend mitigation

13. Slide 6-12 General testing strategies Summary First test result 0–under 4 pCi/L 4–under 10 pCi/L and above No immediate follow-up Follow-up with short-term or long-term test Follow-up with short-term test

14. Slide 6-13 Questions?

15. Slide 6-14 Testing associated with home sales Potential problems Time pressure Accidental violation of test conditions Possibility of tampering

16. Slide 6-15 Testing associated with home sales Short-term options Passive tests –Two sequential tests (one test right after another) –Two simultaneous tests (two tests at the same time) Active test –One continuous monitor

17. Slide 6-16 Real estate option 1 Two sequential tests First test Run the first test for at least 48 hours Return the device to the lab promptly Immediately after the first test is finished, run a follow-up test March 2010 5 6 Begin Test 1 7 8 9 Conduct one short-term test after another

18. Slide 6-17 Real estate option 1 Two sequential tests Follow-up test Use identical device and method Use same units (pCi/L or WL) Place device in same location Run follow-up test for same period as first test –Up to 2 hours difference allowed –Run for at least 48 hours Return device to lab promptly March 2010 5 6 Begin Test 1 7 8 End Test 1 Begin Test 2 9

19. Slide 6-18 Sequential tests Variation in results Expect some variation between any two results Radon levels vary from day to day If variation is large, consider possible causes –Weather –Air pressure –Season –Accidental disturbance of device –Opening of doors or windows –Tampering –Lab error Moderate variation Large variation

20. Slide 6-19 Sequential tests Reporting results What to report –Report both results –Use average of two test results to determine need for mitigation When to report –After second test to discourage tampering

21. Slide 6-20 Real estate option 2 Two simultaneous tests 1.Use two identical devices and methods 2.Test in same location –Place two devices 4 inches apart 3.Run tests for at least 48 hours 4.Return devices to lab promptly March 2010 5 6 Begin Tests 1 and 2 7 8 End Tests 1 and 2 9 Conduct two short-term tests at the same time

22. Slide 6-21 Simultaneous test results Both results are under 4 pCi/L Average will be under 4 pCi/L Report both results and average Recommend future retesting Both results are 4 pCi/L or more Average will be 4 pCi/L or more Report both results and average Recommend mitigation

23. Slide 6-22 Simultaneous test results Special situation One result is under 4 pCi/L and one result is 4 pCi/L or more Average may be under, at, or over 4 pCi/L Consider the difference between the two results

24. Slide 6-23 Simultaneous test results Special situation One result is under 4 pCi/L and one result is 4 pCi/L or more Consider the difference between the two results L = lower result H = higher result Multiply L by 2 and compare with H If H is less than L x 2, the difference is acceptable Report results and average If average is under 4 pCi/L, recommend future retesting If average is 4 pCi/L or more, recommend mitigation If H is greater than or equal to L x 2, the difference is too large Report that the results do not agree Retest

25. Slide 6-24 Simultaneous test results Special situation example L = lower result H = higher result Example 1: L = 3.2 H = 4.2 L x 2 = 6.4 H (4.2) is less than L x 2 (6.4), so the difference is acceptable Report results and average (3.7) Example 2: L = 2.2 H = 4.6

26. Slide 6-25 Simultaneous test results Special situation example L = lower result H = higher result Example 1: L = 3.2 H = 4.2 L x 2 = 6.4 H (4.2) is less than L x 2 (6.4), so the difference is acceptable Report results and average (3.7) Example 2: L = 2.2 H = 4.6 L x 2 = 4.4 H (4.6) is greater than L x 2 (4.4), so the difference is too large Report disagreement of results and retest

27. Slide 6-26 Simultaneous test results Summary Expect some difference between the two results Both results are under 4 pCi/L One result is under 4 pCi/L and one result is 4 pCi/L or more Both results are 4 pCi/L or more Average will be under 4 pCi/L If the higher result is twice the lower result or more, retest If the higher result is less than twice the lower, report both results and average Recommend retesting or mitigation based on average Average will be 4 pCi/L or more Report both results and average Recommend future retesting Report both results and average Recommend mitigation

28. Slide 6-27 Questions?

29. Slide 6-28 Option 3 One continuous test Use any EPA-approved continuous monitor or continuous working-level monitor Use monitor that integrates and records at least every hour If device cannot integrate every hour, use a second device –Use another active device (continuous monitor) or a passive device –Measure sequentially or simultaneously

30. Slide 6-29 Option 3 One continuous test Run test for at least 48 hours Requires about 4 hours for conditions to stabilize –Discard data from these 4 hours or correct them Must have at least 44 continuous (uninterrupted) hours of data for valid average –If you remove any data within that period (for example, if severe weather occurs), results will not be valid

31. Slide 6-30 Option 3 One continuous test Results 0–under 4 pCi/L 4 pCi/L or more Recommend future testing Recommend mitigation

32. Slide 6-31 Questions?

33. Slide 6-32 Summary Testing period –Short-term (2-90 days) –Long-term (91-365 days) –Both provide accurate results Testing strategies –General testing –Testing associated with real estate transactions

34. Slide 6-33 Summary General testing steps 1.Conduct short-term test 2.Determine what follow-up strategy is needed, depending on first result  0 to under 4 pCi/L  4 to under 10 pCi/L  10 pCi/L or above 3.Conduct any required follow-up 4.Examine results to determine what to advise homeowner  When result is under 4 pCi/L, advise future follow-up, especially if major changes are made  When final result is 4 pCi/L or more, advise mitigation

35. Slide 6-34 Summary Real estate options 1.Two sequential tests using passive devices 2.Two simultaneous tests using passive devices 3.One continuous test

36. Slide 6-35 Questions?