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www.pehsu.net/nationalclassroom.html
Webinars
Series of scientific webinars that provide a forum for discourse on scientific
issues.
Live and On-Demand
Case Conferences Journal ClubsGrand Rounds
CE Available
Online Courses
Interactive and Self-Paced
Evidence-based online courses on a variety of
children's environmental health topics.
CE Available
Resource Catalog
Fact sheets, journal publications, reports, and
other resources for parents, community members,
patients and healthcare professionals
Topics included: Air Quality, Pesticides, Natural
Disasters, BPA, Mold, Lead, Mercury
Radon: Is My Family At Risk?Nicklaus Brandehoff, MD and Keith Baker, MDMedical Toxicology FellowsRocky Mountain Poison and Drug CenterDenver, CO
1) Describe radon and where it can be found.
2) Describe known and hypothesized health risks associated with radon exposure.
3) Identify the EPA action level for radon.
4) Examine literature investigating whether there is evidence radon increases the risk of developing lung cancer, leukemia, lymphoma, and CNS malignancies.
5) Apply this information to discussing radon mitigation with patients and with the community.
Objectives
Introduction to Radon
http://www.radontestinginma.com/what-is-radon.html
Ionizing Radiation
What are the types of ionizing radiation?
What are the routes of exposure?
How is radiation and radiation exposure measured?
Ionizing Radiation
Measurements
Disintegrations/ second measured in Becquerels (Bq)
Can also be measured in Picocuries (pCi)
1 pCi = 0.037 Bq
1 pCi/ L = 37 Bq/ m3
Ionizing Radiation
Measurements
Amount of energy of ionizing radiation absorbed by the body or an organ measured in the S.I. unit Grays (Gy)
Different types of different ionizing radiation have different health effects, so a radiation weighting factor (K) is used to convert to a dose equivalent
For alpha K = 20For beta K = 1For gamma K = 1For neutrons K = 5-20
Ionizing Radiation
Measurements
The dose equivalent is then measured using the unit Sieverts (Sv)
1 Gy of alpha radiation = 20 Sv1 Gy of beta radiation = 1 Sv
Exposure to roughly 60 Bq/m3 over the year = exposure to roughly 1 mSv of background radiation
Ionizing Radiation
Radon Mitigation
https://www.youtube.com/watch?v=Mwuev8WTitM
EPA action level for radon is 4 pCi/ L
https://en.wikipedia.org/wiki/Radium_and_radon_in_the_environment
1) Lung cancer is leading causing of cancer related deaths world wide.
2) Radon is an IARC1 for lung cancer.
3) Unclear the role of lung cancer for indoor housing exposures.
4) Limitations of epidemiologic studies.
Background
International Agency of Research on Cancer
IARC Background
Group 1 Carcinogenic to humans 120 agents
Group 2A Probably carcinogenic to humans 81
Group 2B Possibly carcinogenic to humans 299
Group 3Not classifiable as to its carcinogenicity to humans
502
Group 4 Probably not carcinogenic to humans 1
Pubmed search of case-control studies
Search terms “radon exposure” and ”lung cancer”
All studies through December 31, 2015
143 total results -> 100 in English language
Inclusion = 100 cases + 100 controls in study + English language
24 papers included in review
Methods
There is an association between exposure to radon and lung cancer.
Effect is increased in smokers vs non-smokers.
Literature is mixed on the dose response relationship between radon and lung cancer in non-smokers.
Associated lung cancer types include small cell carcinomas, squamous cell carcinomas, and large cell carcinomas.
Results
Heterogeneous study cohort
Variability of “low, medium, high” radon concentrations
Limited studies looking at non-smokers
Limitations
Radon causes lung cancer in all comers
It is unclear the relationship between low exposure to radon and lung cancer in non-smokers
Further studies need to implement further controls to assess the relationship between non-smokers, radon concentrations, and lung cancer
Conclusions
Lung cancer is leading cause of cancer related deaths in Utah.
Utah has the lowest smoking prevalence in the United States.
80% of population in metropolitan areas/20% in rural areas
30% of homes with radon >[4 pCi/L]- National average is 7%
Background
Surveillance and Epidemiology, and End Results Program (SEER) 1991 - 2010
- Lung cancer cases- Stage of cancer- Age and sex of patient- Population attributes
EPA predicted radon concentrations from 1991 - 2010
Multivariate Poisson regression model
Methods
Low = < 2 pCi/L
Moderate = 2 – 4 pCi/L
High = > 4 pCi/L
Smoking rates determined from previous study
Methods
Results
Non-metropolitan areas- poorer- higher smoking rates- less access to health care
Retrospective review
Large data bases compared
Limitations
• Nonmetropolitan counties have a higher rates of lung cancer
compared to metropolitan counties,
• Opposite of other SEER sites.
• Similar rates between metropolitan and nonmetropolitan
counties with similar radon levels.
• Significantly higher among high radon counties than
moderate radon counties.
Conclusion
Radon and Childhood Leukemia, Lymphoma, and CNS Malignancies
Keith Baker, MD
Radon and Leukemia/CNS Malignancies
1) Radon exposure has clearly been associated with development of lung cancer.
2) What about other cancers?
3) Previous studies have shown conflicting results.
4) Limitations of epidemiologic studies.
Background
Specifically examining risk of leukemia or CNS malignancies
Prospective cohort
Children ages 0-15 years
712,674 children in the Oslo, Norway region
437 leukemia cases, 427 CNS cancer cases
Sub-analyses, etc.
Methods
Exposures measured in Bq/m3
EPA action level is 4 pCi/L
For the purpose of this presentation I have converted results from Bq/ m3 to pCi/ L to help make sense of the results in light of EPA recommendations.
Methods
Radon exposure divided into tertiles which were rounded.
1) < 1.4 pCi/L (< 50 Bq/m3)
2) 1.4 – 2.7 pCi/L (50-100 Bq/m3)
3) > 2.7 pCi/L (> 100 Bq/m3)
Methods
Further exposure grouping
1) < 2.7 pCi/L (< 100 Bq/m3)
2) 2.7 – 5.4 pCi/L (100-200 Bq/m3)
3) > 5.4 pCi/L (> 200 Bq/m3)
Also analyzed as continuous variable grouped into 5 groups by increments of 2.7 pCi/L (100 Bq/m3)
Methods
Table 2
1) Results of tertiles without subanalyses showed a few small differences
2) Results of tertiles with subanalyses did not show any statistically significant differences
Results
No association was observed when radon exposure was classified into the exposure categories:
1) < 2.7 pCi/L
2) 2.7 – 5.4 pCi/L
3) > 5.4 pCi/L
Results
Discussion of Results
What can we take from these results?
How does this affect our patients/ our communities?
http://he.memegenerator.net/instance/66439261/linda-richman-mike-myers-coffee-talk-discuss-amongst-yourselves
1) Radon exposure has clearly been associated with development of lung cancer.
2) What about other cancers?
3) Previous studies have shown conflicting results.
4) Limitations of epidemiologic studies.
Background
Specifically examining risk of radon exposure and development of lymphoma
Lymphoma divided into subtypes
Study population estimate 6,523,632 children in Texas
2147 total lymphoma cases further divided into subtype
Sub-analyses, etc.
Methods
Exposures measured in Bq/m3
EPA action level is 4 pCi/L
For the purpose of this presentation I have converted results from Bq/m3 to pCi/L to help make sense of the results in light of EPA recommendations.
Methods
Regional mean radon concentrations assessed by quartile
Cut points based on the distribution across the state
Methods
Arithmetic Mean: 1.24 pCi/LGeometric Mean (95% CI): 1.02 pCi/L (0.68 – 1.53 pCi/L)
Minimum: 0.25 pCi/LMaximum: 3.30 pCi/L
Percentile25th 0.70 pCi/L50th 1.10 pCi/L75th 1.30 pCi/L90th 2.60 pCi/L99th 3.30 pCi/L
Results
Discussion of Results
What can we take from these results?
How does this affect our patients/ our communities?
http://children-learningreading.info/kwrbinfo-boardroom-suggestion.htm
Baseline lymphoma rate 23 per million
DLBCL in this study made up 14.67% of cases so we can extrapolate rate to about 3.4 per million
aIRR of 73% for high exposure group increases rate to 5.9 per million
This would mean an addition of 2.5 cases per million or 1 per 400,000
Prevention/NNT
Assuming approximately 2 children per household this would mean 200,000 homes would need mitigation to prevent 1 case of DLBCL.
Average cost of mitigation is about $1200
200,000 X $1200 = $240,000,000
So we can estimate that to prevent 1 case of DLBCL in the high radon exposure group (in this study), almost a quarter of a billion dollars would have to be spent on mitigation.
Prevention/NNT
Conclusion
What do I tell the public about the risks associated with radon?
Who should have radon mitigation?
What recommendations should I make to my patients and my community?
ACKNOWLEDGEMENTS
Thanks to:
Christopher Hoyte, MDMichael Kosnett, MDMelinda Malamaco, MS
This was supported, in part, by the American College of Medical Toxicology (ACMT) and funded (in part) by the cooperative agreement award number 1 U61TS000238-04 from the Agency for Toxic Substances and Disease Registry (ATSDR).
The U.S. Environmental Protection Agency (EPA) supports the PEHSU by providing partial funding to ATSDR under Inter-Agency Agreement number DW-75-92301301-9. Neither EPA nor ATSDR endorse the purchase of any commercial products or services mentioned in PEHSU publications.
www.pehsu.net/nationalclassroom.html
Webinars
Series of scientific webinars that provide a forum for discourse on scientific
issues.
Live and On-Demand
Case Conferences Journal ClubsGrand Rounds
CE Available
Online Courses
Interactive and Self-Paced
Evidence-based online courses on a variety of
children's environmental health topics.
CE Available
Resource Catalog
Fact sheets, journal publications, reports, and
other resources for parents, community members,
patients and healthcare professionals
Topics included: Air Quality, Pesticides, Natural
Disasters, BPA, Mold, Lead, Mercury