Indoors, however, the air within your home turns over slowly and radon has a tendency to concentrate.
Entry points are cracks in slabs and foundations, unsealed penetrations for plumbing and sumps, the seams between slabs and walls, and, to lesser degrees, from the use of well water, concrete from certain sources, and natural gas heating. The seasonal variation of water table height is also a factor. Modern homes are built with more efficient and better-sealed moisture barrier membranes and a higher degree of insulation than in the past. Despite achieving the desired improvement in energy efficiency, this has led to a lesser degree of passive ventilation. Depending upon the season, indoor warmer air being at a lower pressure than its surroundings, a home may exhibit a “chimney effect,” actively drawing in radon. Stanley, et al. [Ref. 6] point out that higher footprint homes provide more opportunity for radon intrusion, and low-rise construction promotes greater accumulation in living spaces, as does increased ceiling height. This is especially true in the case of homes with larger basement square footage and taller basement ceilings.
Stanley et al. also point out lifestyle effects: we now spend an estimated 87% of our time indoors and the use of air conditioning is increasingly prevalent. Frequent opening of windows is consequently now a less common behavior. Necessary to an acceptable energy efficiency, air conditioning recirculates residential air, thus increasing the oppor-tunity for the accumulation of radon in summer months.
As important as radon assessments are, there has been confusion over the appropriate roles for short and longer-term measurements. Stanley, et al. show that while there is a R2 = 0.805 correlation between 5-day testing and 90+ (average 108) day testing in central Canada, there is essentially zero (R2 = 0.011) correlation between 5-day winter and 5-day summer testing. Longer term testing across several seasons is thus needed for accurate radon assessments.
The EPA has recommended mitigation actions definitely be taken when radon, as measured by its radioactive decay, exceeds 4 pico-Curies per hour per liter of air (4 pCi/hr/L). [Ref. 5] Consideration of mitigation actions is recommended at 2 pCi/hr/L. Some 34 states have also put in place various regulations. [Ref 7] These mainly relate to testing upon the pending sale of real estate (and bear civil and criminal penalties for non-disclosure) and mandatory testing in schools and certain civic buildings.
If your readings are high
There are several actions that may be taken if radon in your home is found to be high. If actionable levels of radon are found, then well known and effective mitigation steps may be taken, some of which are not even very costly. First, it would be wise to see how readings trend over time by moving about an electronic consumer radon detector between different locations of your home. Opening windows more often on hot days may prove helpful. If readings are consistently high, you may wish to explore means of sealing cracks in your slab or foundation should they be accessible. Similarly, are through-holes for sumps or piping well sealed? In the case of consistently elevated readings, it may be wise to bring in a radon mitigation professional, who may recommend installing a 24-hour fan to duct basement or crawl space air above your roofline. Such work may run $2,000 or so. The installation of an HRV (Heat Recovery Ventilator) may be even lower cost. (However, if you elect not to remediate, do quit smoking, since together the outcomes of both exposures are worse than individually.)
The beauty of having a consumer electronic radon measurement device is that a sequence of steps may be explored in determining whether progressive levels of expenditure are necessary. Whatever the expenditure may be, avoiding the chances of serious health issues may be well worth the peace of mind.
Ecosense, Inc.: Solely Dedicated to Radon Measurement Technology
Have the conversation!
If the physician does not ask about whether the patient’s home has been tested, we suggest the patient initiates the conversation. How does your doctor view the importance of testing? There are many resources a doctor can “prescribe” to help with a patient’s decisions on the testing of their home: for instance, the EPA has compiled a convenient guide to state-by-state resources on radon. [Ref. 5] The general practitioner is also critical to the tax-efficient financing of any needed corrective actions. Perhaps not very well known, but with a doctor’s support, before-tax health savings accounts can be tapped to perform potentially lifesaving radon remediations.
In conclusion, if you are a general practitioner, ask the question. If you are a patient, get an opinion from someone you trust. Let’s work together to manage a manageable situation!
References:
1. Field, R.W., American Family Physician, 2018 Sep 1; 98(5): 280-282
2. New lung cancer cases diagnosed annually: Sheehan, D.F., et al., Cancer Med. 2019Jan; 8(1): 94–103.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6346221/
3. Lung cancer deaths due to radon: https://www.epa.gov/radon/health-risk-radon
4. Lifetime costs of lung cancer: https://healthpayerintelligence.com/news/cost-of-cancer-care-reaches-nearly-150b-nationally
5. Radon map of the U.S.: https://www.epa.gov/radon/find-information-about-local-radon-zones-and-state-contact-information#radonmap
6. Stanley, F.K.T., Irvine, J.L., Jacques, W.R. et al., “Radon exposure is rising steadily within the modern North American residential environment and is increasingly uniform across seasons,” Sci Rep 9, 18472 (2019). https://doi.org/10.1038/s41598-019-54891-8
7. State regulations:https://www.ncsl.org/research/environment-and-natural-resources/radon.aspx#2
8. Ecosense, Inc. website: https://ecosense.io
9. “Intercomparison of Commercially Available Active Radon Measurement Devices in a “Discovered” Radon Chamber,” Marco Carmona, et al., Radiological Health Engineering Laboratory Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Consortium for Verification Technology under the Department of Energy National Nuclear Security Administration, award number DE-NA0002534.
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