Health Policies Health effects of radon

1 health policies

1.1 current public health policy efforts
1.2 federal radon action plan
1.3 national radon action plan
1.4 dose-effect model retained
1.5 death toll attributed radon
1.6 radon testing
1.7 mitigation
1.8 detractors

health policies
current public health policy efforts
federal radon action plan

the federal radon action plan, known frap, created in 2010 , launched in 2011. piloted u.s. environmental protection agency in conjunction u.s. departments of health , human services, agriculture, defense, energy, housing , urban development, interior, veterans affairs, , general services administration. goal set forth frap eliminate radon induced cancer can prevented expanding radon testing, mitigating high levels of radon exposure, , developing radon resistant construction, , meet healthy people 2020 radon objectives. identified barriers change limited public knowledge of dangers of radon exposure, perceived high costs of mitigation, , availability of radon testing. result, identified major ways create change: demonstrate importance of testing , ease of mitigation, provide incentives testing , mitigation, , build radon services industry. complete these goals, representatives each organization , department established specific commitments , timelines complete tasks , continued meet periodically. however, frap concluded in 2016 national radon action plan took over. in final report on commitments, found frap completed 88% of commitments. reported achieving highest rates of radon mitigation , new construction mitigation in united states of 2014. frap concluded because of efforts, @ least 1.6 million homes, schools, , childcare facilities received direct , immediate positive effects.  

the national radon action plan

the national radon action plan, known nrap, created in 2014 , launched in 2015. led american lung association collaborative efforts american association of radon scientists , technologists, american society of home inspectors, cancer survivors against radon, children’s environmental health network, citizens radioactive radon reduction, conference of radiation control program directors, environmental law institute, national center healthy housing, u.s. environmental protection agency, u.s. department of health , human services, , u.s. department of housing , urban development. goals of nrap continue efforts set forth frap eliminate radon induced cancer can prevented expanding radon testing, mitigating high levels of radon exposure, , developing radon resistant construction. nrap aims reduce radon risk in 5 million homes, , save 3,200 lives 2020. complete these goals, representatives each organization have established following action plans: embed radon risk reduction standard practice across housing sectors, provide incentives , support test , mitigate radon, promote use of certified radon services , build industry, , increase public attention radon risk , importance of reduction. nrap in action, implementing programs, identifying approaches, , collaborating across organizations achieve these goals.

dose-effect model retained

the dose-effect relationship available of miners cohorts (for higher exposures), exposed radon. studies of hiroshima , nagasaki survivors less informative (the exposure radon chronic, localized, , ionizing radiations alpha rays). although low-exposed miners experienced exposures comparable long-term residence in high-radon dwellings, mean cumulative exposure among miners approximately 30-fold higher associated long-term residency in typical home. moreover, smoking significant confounding factor in miners studies. can concluded miner studies when radon exposure in dwellings compares in mines (above 1000 bq/m), radon proven health hazard; in 1980s little known on dose-effect relationship, both theoretically , statistical.

studies have been made since 1980s, both on epidemiological studies , in radiobiology field. in radiobiology , carcinogenesis studies, progress has been made in understanding first steps of cancer development, not point of validating reference dose-effect model. certainty gained process complex, resulting dose-effect response being complex, , not linear one. biologically based models have been proposed project substantially reduced carcinogenicity @ low doses. in epidemiological field, no definite conclusion has been reached. however, evidence available, threshold exposure, is, level of exposure below there no effect of radon, cannot excluded. l

given radon distribution observed in dwellings, , dose-effect relationship proposed given model, theoretical number of victims can calculated, , serve basis public health policies.

with beir vi model, main health effect (nearly 75% of death toll) found @ low radon concentration exposures, because of population (about 90%) lives in 0-200 bq/m range. under modeling, best policy reduce radon levels of homes radon level above average, because leads significant decrease of radon exposure on significant fraction of population; effect predicted in 0-200 bq/m range, linear model has maximum uncertainty. statistical evidence available, threshold exposure cannot excluded; if such threshold exists, real radon health effect in fact limited homes radon concentrations reaches observed in mines — @ few percent. if radiation hormesis effect exists after all, situation worse: under hypothesis, suppressing natural low exposure radon (in 0-200 bq/m range) lead increase of cancer incidence, due suppression of (hypothetical) protecting effect. low-dose response unclear, choice of model controversial.

no conclusive statistics being available levels of exposure found in homes, risks posed domestic exposures estimated on basis of observed lung-cancer deaths caused higher exposures in mines, under assumption risk of developing lung-cancer increases linearly exposure increases. basis model proposed beir iv in 1980s. linear no-threshold model has since been kept in conservative approach unscear report , beir vi , beir vii publications, lack of better choice:

until [...] uncertainties on low-dose response resolved, committee believes [the linear no-threshold model] consistent developing knowledge , remains, accordingly, scientifically defensible approximation of low-dose response. however, strictly linear dose response should not expected in circumstances.

the beir vi committee adopted linear no-threshold assumption based on understanding of mechanisms of radon-induced lung cancer, recognized understanding incomplete , therefore evidence assumption not conclusive.

death toll attributed radon

in discussing these figures, should kept in mind both radon distribution in dwelling , effect @ low exposures not precisely known, , radon health effect has computed (deaths caused radon domestic exposure cannot observed such). these estimations dependent on model retained.

according these models, radon exposure thought second major cause of lung cancer after smoking. iowa has highest average radon concentration in united states; studies performed there have demonstrated 50% increased lung cancer risk prolonged radon exposure above epa s action level of 4 pci/l.

based on studies carried out national academy of sciences in united states, radon second leading cause of lung cancer after smoking, , accounts 15,000 22,000 cancer deaths per year in alone. united states environmental protection agency (epa) says radon number 1 cause of lung cancer among non-smokers. general population exposed small amounts of polonium radon daughter in indoor air; isotopes po , po thought cause majority of estimated 15,000–22,000 lung cancer deaths in every year have been attributed indoor radon. surgeon general of united states has reported on 20,000 americans die each year of radon-related lung cancer.

in united kingdom, residential radon be, after cigarette smoking, second frequent cause of lung cancer deaths: according models, 83.9% of deaths attributed smoking only, 1.0% radon only, , 5.5% combination of radon , smoking.

the world health organization has recommended radon reference concentration of 100 bq/m (2.7 pci/l). european union recommends action should taken starting concentrations of 400 bq/m (11 pci/l) older dwellings , 200 bq/m (5 pci/l) newer ones. after publication of north american , european pooling studies, health canada proposed new guideline lowers action level 800 200 bq/m (22 5 pci/l). united states environmental protection agency (epa) recommends action dwelling concentration higher 148 bq/m (4 pci/l), , encourages action starting @ 74 bq/m (2 pci/l).

epa recommends homes should monitored radon. if testing shows levels less 4 picocuries radon per liter of air (160 bq/m), no action necessary. levels of 20 picocuries radon per liter of air (800 bq/m) or higher, home owner should consider type of procedure decrease indoor radon levels. instance, radon has half-life of 4 days, opening windows once day can cut mean radon concentration 1 fourth of level.

the united states environmental protection agency (epa) recommends homes fixed if occupant s long-term exposure average 4 picocuries per liter (pci/l) 148 bq/m. epa estimates 1 in 15 homes in united states has radon levels above recommended guideline of 4 pci/l. epa radon risk level tables including comparisons other risks encountered in life available in citizen s guide. epa estimates nationally, 8% 12% of dwellings above maximum safe levels (four picocuries per liter—the equivalent 200 chest x-rays). united states surgeon general , epa both recommend homes tested radon.

the limits retained not correspond known threshold in biological effect, determined cost-efficiency analysis. epa believes 150 bq/m level (4 pci/l) achievable in majority of homes reasonable cost, average cost per life saved using action level $700,000.

for radon concentration in drinkable water, world health organization issued guidelines (1988) remedial action should considered when radon activity exceeded 100 kbq/m in building, , remedial action should considered without long delay if exceeding 400 kbq/m.

radon testing

a radon test kit.

there relatively simple tests radon gas. radon test kits commercially available. short-term radon test kits used screening purposes inexpensive, in many cases free. discounted test kits can purchased online through national radon program services @ kansas state university or through state radon offices. information local radon zones , specific state contact information can accessed through epa map @ https://www.epa.gov/radon/find-information-about-local-radon-zones-and-state-contact-information.  the kit includes collector user hangs in lowest livable floor of dwelling 2 7 days. charcoal canisters type of short-term radon test, , designed used 2 4 days. user sends collector laboratory analysis. both devices passive, meaning not need power function.

it should noted accuracy of residential radon test depends upon lack of ventilation in house when sample being obtained. thus, occupants instructed not open windows, etc., ventilation during pendency of test, 2 days or more.

long-term kits, taking collections 3 months 1 year, available. open-land test kit can test radon emissions land before construction begins. lucas cell 1 type of long-term device. lucas cell active device, or 1 requires power function. active devices provide continuous monitoring, , can report on variation of radon , interference within testing period. these tests require operation trained testers , more expensive passive testing. national radon proficiency program (nrpp) provides list of radon measurement professionals.

radon levels fluctuate naturally. initial test might not accurate assessment of home s average radon level. transient weather can affect short term measurements. therefore, high result (over 4 pci/l) justifies repeating test before undertaking more expensive abatement projects. measurements between 4 , 10 pci/l warrant long-term radon test. measurements on 10 pci/l warrant short-term test abatement measures not unduly delayed. purchasers of real estate advised delay or decline purchase if seller has not abated radon 4 pci/l or less.

since radon concentrations vary substantially day day, single grab-type measurements not useful, except means of identifying potential problem area, , indicating need more sophisticated testing. epa recommends initial short-term test performed in closed building. initial short-term test of 2 90 days allows residents informed in case home contains high levels of radon. long-term tests provide better estimate of average annual radon level.

mitigation

transport of radon in indoor air entirely controlled ventilation rate in enclosure. since air pressure lower inside houses outside, home acts vacuum, drawing radon gas in through cracks in foundation or other openings such ventilation systems. generally, indoor radon concentrations increase ventilation rates decrease. in ventilated place, radon concentration tends align outdoor values (typically 10 bq/m, ranging 1 100 bq/m).

radon levels in indoor air can lowered in several ways, sealing cracks in floors , walls increasing ventilation rate of building. listed here of accepted ways of reducing amount of radon accumulating in dwelling:

·         improving ventilation of dwelling , avoiding transport of radon basement, or ground, living areas;

·         installing crawlspace or basement ventilation systems;

·         installing sub-slab depressurization radon mitigation systems, vacuum radon under slab-on-grade foundations;

·         installing sub-membrane depressurization radon mitigation systems, vacuum radon under membrane covers ground used in crawlspace

foundations;

·         installing radon sump system in basement;

·         sealing floors , walls (not stand-alone solution); and

·         installing positive pressurization or positive supply ventilation system.

the half-life radon 3.8 days, indicating once source removed, hazard reduced within approximately 1 month (seven half-lives).

positive-pressure ventilation systems can combined heat exchanger recover energy in process of exchanging air outside, , exhausting basement air outside not viable solution can draw radon gas dwelling. homes built on crawl space may benefit radon collector installed under radon barrier, or membrane (a sheet of plastic or laminated polyethylene film covers crawl space floor).

astm e-2121 standard reducing radon in homes far practicable below 4 picocuries per liter (pci/l) in indoor air.

in us, approximately 14 states have state radon programs train , license radon mitigation contractors , radon measurement professionals. determine if state licenses radon professionals contact state health department. national environmental health association , national radon safety board administer voluntary national radon proficiency programs radon professionals consisting of individuals , companies wanting take training courses , examinations demonstrate competency. without proper equipment or technical knowledge, radon levels can increase or create other potential hazards , additional costs. list of certified mitigation service providers available through state radon offices, listed on epa website @ www.epa.gov/radon/whereyoulive.html. indoor radon can mitigated sealing basement foundations, water drainage, or sub-slab, or sub-membrane depressurization. in many cases, mitigators can use pvc piping , specialized radon suction fans exhaust sub-slab, or sub-membrane radon , other soil gases outside atmosphere. of these solutions radon mitigation require maintenance, , important continually replace fans or filters needed continue proper functioning.

since radon gas found in soil , rocks, not able move air, underground water sources. radon may present in water , can released air in homes when water used showering , other household uses. if suspected private or drinking water may affected radon, national radon program services hotline @ 1-800-sos-radon can contacted information regarding state radon office phone numbers. state radon offices can provide additional resources, such local laboratories can test water radon.

if determined radon present in private well, installing either point-of-use or point-of-entry solution may necessary. point-of-use treatments installed @ tap, , helpful in removing radon drinking water. address more common problem of breathing in radon released water used during showers , other household activities, point-of-entry solution may more reliable. point-of-entry systems involve granular activated carbon filter, or aeration system; both methods can remove radon before enters home’s water distribution system. aeration systems , granular activation carbon filters both have advantages , disadvantages, recommended contact state radon departments or water treatment professional specific recommendations.

detractors

the high cost of radon remediation in 1980s led detractors arguing issue financial boondoggle reminiscent of swine flu scare of 1976. further argued results of mitigation inconsistent lowered cancer risk, when indoor radon levels in lower range of actionable exposure level.