1. Illinois Footprint Project
Josiah Alamu, PhD, MPH
Lenore Killam, DPAc, MPH
Sharron LaFollette, PhD

2. Overview Introduction Specific Aims Methods Results
Significance of findings
Conclusion

3. Illinois Footprint Policy
Section Measurement Protocol
Short-term or long-term measurements
Measurements shall be made at the same time, in each lowest structural area suitable for occupancy

4. Three Homes – Different Foundation Types

5. A Home - Three Foundation Types

6. Specific Aims From the Aggregate Data From the Individual Homes
To present summary statistics of radon measurements according to the footprint
From the Individual Homes
To examine the correlation between radon concentration by footprint

7. Methods Data from: Licensee residential radon measurement data (IEMA)
Year: to 2011
Location: All counties in Illinois

8. Statistical Analysis For specific Aim 1
ANOVA & Tukey Studentized (HSD) Test
For specific Aim 2
Pearson Correlation coefficient
Proportion test

9. Description of Data General Description of Data
237,061 measurements from 144,832 unique addresses
360 Illinois licensed radon measurement professionals
68.75% of measurement device was CR

10. Results – Summary Statistics
Description
Basement
Crawlspace
Slab
No. of houses monitored
121,203
24,313
11,388
Mean (pCi/L)
5.13
3.58
3.59
SD (pCi/L)
5.33
3.40
4.75
Min (pCi/L)
1.01
1.10
Max pCi/L)
442.50
116.50
362.60
Median(pCi/L)
3.60
2.60
2.50
P25 – P75
2.20 – 6.30
1.70 – 4.30
1.60 – 4.30

11. Results – ANOVA (Tukey)
Comparison
Difference Between Means
95% CI
Significant at 𝛂=𝟎.𝟎𝟓
Basement vs. Slab –
***
Basement vs. Crawlspace –
Crawlspace vs. Slab – NS

12. Results
General
45% of the basement radon concentration exceeded the US EPA action level of 4 pCi/L
28% of the radon measurement above crawlspace exceeded the US EPA action level of 4 pCi/L
27% of the radon measurement above the slab exceeded the US EPA action level of 4 pCi/L

13. Basement vs. Crawlspace

14. Basement vs. Crawlspace
Crawlspace GT Basement
Number of Houses
Proportion (%)
16949
Yes
2096
12.37 No
14853
87.63

15. Basement vs. Crawlspace
424 (20.23%) of 2,096 houses have their crawlspace radon concentration greater or equal to 4pCi/L

16. Basement vs. Slab

17. Basement vs. Slab Slab GT Basement Number of Houses Proportion (%)
5336
Yes
1165
21.83 No
4171
78.17

18. Basement vs. Slab
232 (19.91%) of 1165 houses have their slab radon concentration greater or equal to 4pCi/L

19. Slab vs. Crawlspace

20. Slab vs. Crawlspace Crawlspace GT Slab Number of Houses Proportion (%)
1819
Yes
618
33.97 No
1201
66.03

21. Slab vs. Crawlspace
79 (12.78%) 618 houses have their crawlspace radon concentration greater or equal to 4pCi/L

22. Significance of Findings 1
19.91 % to 20.23% of radon measurement at Crawlspace and Slab would have been missed, if we measure at basement alone

23. Significance of Findings 2
False sense of safety to home owners
Approximately, $1 million loss to business in the state of Illinois

24. Conclusion
Based on the results and findings, the current Illinois footprint requirement policy should be maintained

25. Reference
Field RW, et al. Residential radon gas exposure and lung cancer: the Iowa Radon Lung Cancer Study. Am J Epidemiol Jun 1;151(11):109 – 102
IEMA Status report for radon in Illinois. State of Illinois (IISG 1095 – 200 – 8/06) PO # 214
Field RW, et al. The Iowa radon lung cancer study- Phase I: Residential radon gas exposure and lung cancer. Sci Total Environ May 14;272(1 – 3):67 – 72
Darby S, et al. Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies. BMJ, doi: /bmj (published 21 December 2004)

26. Acknowledgement
In partnership with:

27. Presenter’s Information
Josiah Alamu, PhD, MPH
Tel: