Radon in Ontario: A public health perspective

Emily Peterson, MPH

Environmental Health and Knowledge Translation Scientist National Collaborating Centre for Environmental Health

Environmental Health Services, BC Centre for Disease Control

March 6th, 2015

1

Overview

• Background

• Lung cancer burden from radon in Ontario

• Knowledge to action – How did we communicate the burden results?

– Some of the challenges we face

2

Public Health Perspective

• Population level health analysis

• How can we prevent the largest number of lung cancer cases dues to radon ?

Public Health in Ontario

• Population of 13 million

• 36 Health Units

• Need for local level research and information

Burden of Illness Project: Purpose

• Calculate the lung cancer burden of illness attributable to Radon in Ontario

• Estimate number of lung cancer deaths that can be prevented through remediation

• Perform calculations separately for each of the 36 health units in Ontario

5

Results: Overview • 13.6% (95% CI: 11.0-16.7%) of lung cancer

deaths in Ontario attributable to radon

• 847 (95% CI: 686-1039) lung cancer deaths (2007) due to radon

– 84% in ever-smokers – 16% in never-smokers

• Radon is an important contributor to lung

cancer deaths in Ontario 7

8

91 (11%) deaths prevented

Current Canadian Guideline

9

149 (18%) deaths prevented

US Guideline = 148Bq/m3

10

233 (28%) deaths prevented

WHO suggested guideline

11

389 (46%) deaths prevented

• Large portion of radon related lung cancer deaths in Ontario are from exposures to levels below the current Canadian guideline

• 11% of radon related lung cancer deaths prevented if we test and remediate all homes in Ontario using the current Canadian guideline

12

Health Unit Burden Estimates

13

Health Unit

Percent of lung cancer deaths caused by Radon

Number of Lung Cancer

Deaths Due to Radon

Number (percentage) of radon-related lung cancer

deaths that can be prevented

Mean (95% Confidence Interval) 100 (Bq/m3) 200 (Bq/m3)

Health Unit 1 25.3 (21.7-29.6) 21 9 (42%) 5 (23%)

Health Unit 2 9.1 (6.9-11.6) 24 1 (4%) 0 (0%)

• For some but not all Health Units, testing and

remediation to current guideline may prevent a portion of radon related lung cancer deaths

14

15

Available at: http://www.publichealthontario.ca/en/eRepository/radonInfographic_Final.pdf

16

Available at: http://www.publichealthontario.ca/en/DataAndAnalytics/Pages/Ontario-Health-Profile.aspx#.VG0JpzTF-So

Bill 11, Radon Awareness and Prevention Act 2014

“…if we adopted the American guideline, we would save some 149 individuals from lung cancer deaths, the WHO guideline, at 100 Bq/m3 would prevent some 233 lungs cancer deaths.” “………..A snippet of that says: “An alternative approach to promoting individual adherence to the radon guideline is to design and install effective radon-preventive measures into buildings during initial construction through mandatory building codes…”

Quote: Ontario, Legislative Assembly, Official Report of Debates (Hansard), 40th Parl, 2nd Sess, No. 57 (12 September 2013). Available from: http://www.ontla.on.ca/house-proceedings/transcripts/files_pdf/12-SEP-2013_L057.pdf

Quote: Ontario, Legislative Assembly, Official Report of Debates (Hansard), 41st Parl, 1st Sess, No10 (17 July 2014) http://www.ontla.on.ca/house-proceedings/transcripts/files_pdf/17-JUL-2014_L010.pdf

Test and Remediate: Does it work?

• Onus on individual

• How many homeowners test? Of those who test, how many remediate? Are those most at risk testing and remediating?

• 96% of Canadians have not tested their home (Canadian Cancer Society, 2014)

• Only addresses 11% of the burden with current guideline

• Test and remediate only option for older buildings

• Need for evaluation of what works

18 Canadian Cancer Society (2014) (http://www.cancer.ca/en/about-us/for-media/media-releases/national/2014/radon-survey/?region=on),

The role of home warranties

• Radon home warranty in Ontario: • up to 7 years after purchase • homes above Canadian guideline

• Economic incentive to test and remediate after buying a new home?

• Lower guideline for new homes?

• Way to drive building practices to prevent radon entry?

19

http://tarion.intelliresponse.com/index.jsp?interfaceID=1&respId=-1&requestType=&sourceId=1&question=%20radon

Building codes: Do they work?

• Prevent radon entry/buildup

• Address exposure to lower levels of radon and larger portion of burden in Ontario

• What are effective building codes? • National vs Ontario building codes

• Building turnover • 37 years for 50% turnover in Ontario

20

Next Steps

• Continue to develop and implement radon resistant building technologies

• Continue to increase awareness, but evaluate effectiveness

• Consider a lower radon guideline

• Consider the role of home warranties

Contributors o Work done at Public Health Ontario o Ray Copes o Lennon Li o JinHee Kim o Amira Aker o Keven Brand o Elaina MacIntyre o Public Health Ontario Communications o Public Health Ontario Central Analytics

22

Thank You

Questions?

emily.peterson@bccdc.ca

23

Appendix

24

Approach • Used methodology proposed by Brand et al. (2005)

based on the BEIR VI report (1999)

• Calculated population attributable risk percent (PAR%) by health unit

– PAR% = Percent of all lung cancer deaths that are due to radon

• Estimated number of lung cancer deaths that can be prevented if all homes above 50, 100, 150 and 200 Bq/m3 were remediated to background levels

25

Methodology: Calculations • Calculated excess risk ratio of radon related lung cancer

mortality

• Used Monte Carlo Simulation to account for variability – 120M simulations

• Abridged life tables used to calculate risk of lung cancer and life expectancy in the exposed and unexposed populations

• Calculated PAR% and Estimated number of radon attributable lung cancer deaths

• All calculations completed by health unit for ever-smokers, never-smokers and the complete population

26

Methodology: Data Sources

• Cross-Canada Survey of Radon in Homes (Health Canada)

• Proportion of population living in apartment buildings by health unit (Statistics Canada)

• Proportion of ever-smokers in population by health unit (CCHS)

• All cause and lung cancer mortality by health unit (InteliHEALTH Ontario)

• RR for lung cancer mortality and all-cause mortality due to smoking (American Cancer Society)

27