AccuTron Posted December 12, 2013 Posted December 12, 2013 The other night I was curious. My home had a radon test twenty years ago when it was purchased. The test struck me as a joke at the time. I was to seal off one room for a day, no people coming through, doors and windows closed. It is a converted garage that sits directly upon soil, under the flooring is a concrete pad without a crawlspace. The rest of the house has a crawlspace with limited ventilation, but in the winter the furnace is flushing it by using combustion air. In the summer, the windows are open. So what was being measured by this score of 11 pCi/liter? The first dozen sites said the same thing, radon causes residential lung cancer, and such and such are the desired radon levels. They were all repeating the same info from the EPA. (With this and climate fraud, I'm seeing why some conservatives want to defund the EPA.) Then I found this link at wiki.answers. When I first viewed this, it was a text slideshow, but now it's not. Maybe I got my links confused. Either way, it's the text we need. What is a dangerous level of radon Excerpts: "What we do know is that, contrary to popular belief, there is no known additional risk of cancer associated with radon levels as normally seen in houses. In fact, there is no science to support the common practice of radon measurement and radon mitigation in homes. The common practice is a "policy practice" not supported by science." and "...there is a growing body of data from epidemiological (case-control) studies showing a correlation between lung cancer and radon exposures in homes, that "correlation" to which they are referring is actually a NEGATIVE correlation. In other words, the correlation is inversely related to the radon concentration - This means that the growing body of data from epidemiological (case-control) studies are showing that the lung cancer rate DECREASES with increasing radon concentrations seen in residential settings." (Original boldface.) (Visitors: read further down this thread for more depth of topic.)
ribuck Posted December 12, 2013 Posted December 12, 2013 The wiki.answers page to which the OP links claims a negative correlation between radon and cancer. It mentions the BEIR VI report as the source of the claim, but doesn't link to it. You can find the BEIR VI report here:books.google.co.uk/books?isbn=0309056454 All I can see is solid evidence for positive correlation. The report's conclusions state that between 3000 and 33,000 deaths occur from radon-induced cancer each year in the United States, while acknowledging that the quantity and quality of data is not sufficient for a more precise estimate. This is followed by a couple of hundred pages of detailed data and careful analysis. If AccuTron (or anyone else) thinks the report's conclusions are flawed, they should point to the source of error within that report. However, one thing that AccuTron posted is not disputed by anyone: there is no known additional risk of cancer associated with radon levels as normally seen in houses The purpose of testing a house for radon is to identify the small number of houses that have radon levels well above those "normally seen in houses". We tested our house for radon last year. We paid £45 for two small devices that measured the radon. We left them in place for two months, one in a living room and one in a bedroom, then sent them off for analysis. As expected, our house had a very low level of radon, as do most houses.
AccuTron Posted December 13, 2013 Author Posted December 13, 2013 Thanks for the link. Another detective book! I'll take time on it. I first notice that it's a 1999 publication. The other source implied a growing body of data, so that's over a dozen years of research not yet done. What parts did you read? There are many pages, and some of them are omitted from this online sampler. (I may have not followed my own advice about digging and digging more. I probably should have put a question mark in the topic title, don't see how to edit that.) As I'm reading up on radon in general, before getting to your link, a question pops into my head. I've been following Fukushima closely at ENENews.com – Energy News and somewhere in the blizzard of info there, I was reading links from readers, and there seems to be a reasonable suspicion that if we have strong radiation doses, we're more or less done for, no surprise there -- but for minor doses, it may have some value regarding cellular repair mechanisms staying tuned up, similar to an immune system. We are reminded that all life has evolved with levels of natural background radiation, be it ground, solar, or galactic types. The fear from radon, as I make it so far, is the lodging in the lungs of what are minor doses with relatively short half lives. Short half life means it keeps going off rapidly, a down side, but not for long periods. Could that be considered a minor dose? The BEIR Introduction references miner studies as it's major input, along with animal studies, and follow up residential studies. I'm curious about the details. A miner is surrounded by rock with possible natural radiation.
AccuTron Posted December 13, 2013 Author Posted December 13, 2013 The story so far.... This seems written by responsible people, nice to see. The body of evidence is from 11 studies of underground miners, for uranium, or tin, or other things. "...And all inhale dust and other pollutants...." Only 6 of the 11 studies had "some" smoking information, so it sounds like cigarette smoking effects are strongly mixed in. There were 8 residential studies; and "the estimates obtained...are very imprecise...." "Other weaknesses...are errors in estimating exposure and the limited potential for studying modifying factors...." The residential studies were not included in analysis due to "very limited statistical power" but seemed to agree with linear downward extrapolation of miner data. Animal studies were "very limited" and seem mostly to be about comparing radon with and without cigarette smoke; they gave "conflicting" results. Responses to radon may vary markedly by animal species. NOTE: the miners showed a NEGATIVE cancer correlation when radon exposures were highest. (This is PDF and not easy to cut and paste, forgive my blurry eyes if I can't find it again.) I think they are referring to much higher exposures than even a high residential reading, but it's a curious thing to note. The exposure/effects curve is not purely linear. Elsewhere, the committee admits that they are assuming there is not a low-level threshold that is not dangerous, that they are extrapolating downward from high miner exposures. They freely admit it might be there, which is to say, the low level exposure data is unknown at the time. They also state that the linear model is an assumption, and it may be true that it's not linear, but was not within the limits of then-current studies to know. The committee felt that if there was a threshold below 4pC/l, it didn't change benefits from mitigating higher levels. Thus the "4" as a safe limit is introduced. They state that a given human lung epithelial cell, at low radon levels, would get only one alpha particle hit per human lifespan. They also point out that the miner data is from an environment in which multiple cell hits are the norm, and it is comparing two different things. The committee supports the notion that only a single hit can cause a cancer, and that single cells can become cancerous. I wonder how many of those single hits actually are carcinogenic. There must be a bunch of ways to damage a cell, and it's damaged in a way that doesn't involve runaway replication. I'll still read, but what I'm seeing is what the original link suggested: it's extrapolated from underground miners and leaves gaps and honest questions about residential exposure. To quote from a Harry Nilsson work, The Point, "You see what you want to see, and you hear what you want to hear." After that, the character speaking went soundly to sleep, and now maybe you want to.
ribuck Posted December 13, 2013 Posted December 13, 2013 NOTE: the miners showed a NEGATIVE cancer correlation when radon exposures were highest. (This is PDF and not easy to cut and paste, forgive my blurry eyes if I can't find it again.) No need to cut and paste the PDF, just post the page number and we'll see whether or not it supports the claim in your original post (which was that in residential settings an increase in radon was associated with a reduction in cancer). Unless you have data which supports that specific claim, it seems irrational for you to tell people not to have their home tested. I encourage you to withdraw that statement. In my opinion, it's worthwhile to test any high-risk house. A high-risk house is one that is built over radioactive granite (maps are widely available on the web) and which has neither a well-ventilated underfloor nor a radon-resistant underfloor barrier. You asked how much of the report I read. I read all of the textual parts that are available online. I closely read about a dozen pages of the detailed analysis, but found that I couldn't follow all of the math. Nevertheless I satisfied myself that the report's authors were taking account of the various factors that you have raised (correlation with smoking, mining vs residential, linear relation between dose and harm at low doses not fully proven, etc). The fact that these things are somewhat uncertain doesn't invalidate the whole study; it just explains why the estimate of excess deaths has such a wide range (3000 to 33000 per year in the US).
AccuTron Posted December 13, 2013 Author Posted December 13, 2013 I removed that statement. Page number, good idea, will do so in the future. I got the impression that they could not remove smoking conclusively since the original miner data from 11 studies was rather incomplete regarding smoking data for those miners. Perhaps I should not be so conclusive. The original point was that there was not back then data on residential levels normally encountered, so it was a "guessing" zone, and that seems to be true in the BEIR study. The "don't worry" claim from the original link seemed to say it was from residential studies done after the report we're discussing here. I'm looking into more recent studies...which I should've done before even starting this. Humble pie moment. This one supports the radon risk idea: THE IOWA RADON LUNG CANCER STUDY (They also say that controlling for other factors, lung cancer could be lessened by less red meat and more yellow-green veggies.) This link, late nineties, says that the negative correlation results should be discounted because of mistaken or confusing factors. http://www.ladep.es/ficheros/documentos Bottom of first page in link, actually p. 49 from original journal. I downgrade my original conviction, to intrigued confusion. I'm noticing that 1990's residential studies show weak or no radon risks, but that 2000's studies do. Homes are not laboratories, difficult to control for factors.
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