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

Overview Introduction Specific Aims Methods Results Significance of findings Conclusion

Illinois Footprint Policy Section 422.130 Measurement Protocol Short-term or long-term measurements Measurements shall be made at the same time, in each lowest structural area suitable for occupancy

Three Homes – Different Foundation Types

A Home - Three Foundation Types

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

Methods Data from: Licensee residential radon measurement data (IEMA) Year: 2003 to 2011 Location: All counties in Illinois

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

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

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

Results – ANOVA (Tukey) Comparison Difference Between Means 95% CI Significant at 𝛂=𝟎.𝟎𝟓 Basement vs. Slab 1.54791 1.41976 – 1.67606 *** Basement vs. Crawlspace 1.54973 1.45784 – 1.64161 Crawlspace vs. Slab -0.00182 -0.15029 – 0.14665 NS

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

Basement vs. Crawlspace

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

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

Basement vs. Slab

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

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

Slab vs. Crawlspace

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

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

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

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

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

Reference Field RW, et al. Residential radon gas exposure and lung cancer: the Iowa Radon Lung Cancer Study. Am J Epidemiol. 2000 Jun 1;151(11):109 – 102 IEMA 2006. 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. 2001 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:10.1136/bmj.38308.477650.63 (published 21 December 2004)

Acknowledgement In partnership with:

Presenter’s Information Josiah Alamu, PhD, MPH jalam3@uis.edu Tel: 217-206-8485