Radon from Concrete

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Author Message Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1758 Registered: 05-2003 Posted on Thursday, June 15, 2017 - 05:35 pm:    Has anyone heard of radon being emitted from concrete, perhaps due to use of fly ash. This sounds ridiculous as I know fly ash has been thoroughly tested, but its a rumor that is circulating in So Florida, probably from radon mitigation consultants. Guest (Unregistered Guest) Unregistered guest Posted on Thursday, June 15, 2017 - 07:16 pm:    I don't know about the fly ash, but I could see it being emitted from concrete if the aggregate naturally contained bits of uranium or radium; the decay of which would produce radon gas. Some types of granite naturally contains bits of uranium and consequently some granite aggregates used for concrete would as well. Radon test kits are fairly inexpensive and would tell you if the exposure to radon gas is severe enough to cause concern, and subsequent mitigation. Mitigation is usually simply venting areas where radon gas accumulates. It is much denser than air so places like basements, crawl spaces, under slabs on grade, etc. are areas of concern where radon is prevalent. Proving that whatever radon might be found in those areas is from any nearby concrete, or the nearby soil itself, would probably be problematic and difficult. Miami-Dade County has a moderate potential for radon anyway. I don't know why someone would need to blame it on concrete, but I suppose it's possible. http://www.city-data.com/radon-zones/Florida/Florida.html Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1759 Registered: 05-2003 Posted on Thursday, June 15, 2017 - 10:02 pm:    The question came up on highrise work, radon levels measured at elevated slabs, after 30 years I've only had one project where radon was found, this was in SW Florida on the Gulf in a highrise project, on an upper floor. For a while we had a scare that Granite Countertops were a potential source of radon, but that rumor faded pretty quick. Michael Chusid, RA FCSI CCS Senior Member Username: michael_chusid Post Number: 291 Registered: 10-2003 Posted on Thursday, June 15, 2017 - 11:01 pm:    Never assume fly ash has been thoroughly tested. It varies from power plant-to-plant, from year to year according to source of coal, and from hour to hour according to the electrical generation needs of the generation plant. It is not tested by its producers - the coal plants, and the firms that market fly ash range from quality outfits to guys with a pick-up truck and front end loader. if they test it, it is generally for pozzolanic properties. If you want more info, the American Coal Ash Association is the industry's mouthpiece. Michael Chusid, RA FCSI CCS www.chusid.com www.buildingproduct.guru 818-219-4937 Guest (Unregistered Guest) Unregistered guest Posted on Friday, June 16, 2017 - 11:10 am:    Jerome, what radon levels were the tests showing at the elevated slabs? Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1761 Registered: 05-2003 Posted on Friday, June 16, 2017 - 01:50 pm:    Someday the Architect may share that information with me, but for now its above my pay grade. The condo job in SW Florida was completed in 2001, statute of limitations is past, I still speak to that client, but they refuse to share. Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1762 Registered: 05-2003 Posted on Friday, June 16, 2017 - 01:51 pm:    The homeowner did settle with the Developer, out of court, rumor has it she did very well. Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1763 Registered: 05-2003 Posted on Friday, June 16, 2017 - 01:54 pm:    As did the lawyers... John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1720 Registered: 03-2002 Posted on Sunday, June 18, 2017 - 06:41 pm:    I'm surprised radon would be anywhere in South Florida given that it is associated with the presence of granite. I thought that was rare down there. It is present here in New England, but not in every location, even though the NE states sit on a big granite rock. (It's not called bedrock for no reason.) I'm surprised about the idea of it being in coal ash. Coal, the product of plant metamorphosis into a carboniferous form, would seem to be very unlikely to contain the uranium minerals that generate radon. Concrete aggregate, maybe, but it would have had to come some distance, no, to be found in concrete in S. Florida? Is it common to import aggregate? Also, a large settlement may have no connection with the actual presence of radon, since as most here know, settlements are typically reached mostly to avoid the cost of litigation. Jerome J. Lazar, RA, CCS, CSI, NCARB Senior Member Username: lazarcitec Post Number: 1765 Registered: 05-2003 Posted on Monday, June 19, 2017 - 12:07 am:    Thanks Fellow 4specers,for the radon knowledge, at least I know more than I did last Thursday, it sounds like this is just another crazy rumor, I will wait until I hear more from clients. Hell if I have to include a radon prevention spec in a Project Manual per Owner request, so be it. Guest (Unregistered Guest) Unregistered guest Posted on Monday, June 19, 2017 - 11:15 am:    John, coal definitely contains uranium and other radioactive elements. The following linked article is trying to be sensational (as evidenced by the sensationalist title) so take it with a grain of salt; https://www.scientificamerican.com/article/coal-ash-is-more-radioactive-than-nuclear-waste/ More to the point of the thread (and so I'm not labelled an alarmist) I'll add the following quoted from a USGS fact sheet: https://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.html "Fly ash is commonly used as an additive to concrete building products, but the radioactivity of typical fly ash is not significantly different from that of more conventional concrete additives or other building materials such as granite or red brick. One extreme calculation that assumed high proportions of fly-ash-rich concrete in a residence suggested a dose enhancement, compared to normal concrete, of 3 percent of the natural environmental radiation. "Another consideration is that low-density, fly-ash-rich concrete products may be a source of radon gas. Direct measurement of this contribution to indoor radon is complicated by the much larger contribution from underlying soil and rock (see fig. 4). The emanation of radon gas from fly ash is less than from natural soil of similar uranium content. Present calculations indicate that concrete building products of all types contribute less than 10 percent of the total indoor radon." +1 for SCIENCE Brett Scarfino (Unregistered Guest) Unregistered guest Posted on Monday, June 19, 2017 - 11:51 am:    I recall radon being more common if your sitting on glacial till (i.e. weathered granite). Your water soluble and gaseous decay products (radium/radon) would have an easier time migrating than when stuck in bedrock. My radon level jumps with both changes in seasons as well as rain events. I purchased an electronic monitor for around $100, and passed it around to a number of friends and family, fyi. Continuous peace of mind before and after my mitigation system was installed a few years ago. I was under the impression that opponents of coal cited K-40 and C-14 radio isotopes? If radon is the concern, the coal would need to contain U, Th, or their daughters to have radon. Maybe (some) coal does, I don't know. John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1721 Registered: 03-2002 Posted on Monday, June 19, 2017 - 05:21 pm:    Very interesting, but clearly no cause for concern in concrete since it seems to be the same levels with our without fly ash. If there are any chemists or hobby-chemists, I'm curious: I know that flue gas desulfurization removes sulfur from the combustion exhaust stream of a coal plant, producing gypsum. Does the material NOT removed this way form the fly ash? Would the gypsum produced by this method contain some uranium or thorium like the fly ash? If so, would a similar (non-) issue exist for drywall? Does mined gypsum contain uranium? Michael Chusid, RA FCSI CCS Senior Member Username: michael_chusid Post Number: 292 Registered: 10-2003 Posted on Monday, June 19, 2017 - 06:52 pm:    I recall that radon is a problem primarily where it accumulates and is not vented, like enclosed basements with limited ventilation. Is this correct? If it is correct, and your building has plenty of fresh air, maybe it is not a problem. I spent a lot of time in South Florida visiting my grandparents in the 1960s. I recall lots of jalousie windows and natural ventilation. Has this changed? Michael Chusid, RA FCSI CCS www.chusid.com www.buildingproduct.guru 818-219-4937 Brett Scarfino (Unregistered Guest) Unregistered guest Posted on Tuesday, June 20, 2017 - 09:13 am:    Michael - one relative who borrowed the monitor had very high radon throughout their ranch; in the full basement AND on the main floor. For that matter, half of their basement is a framed atrium with continuous windows (which in my opinion, are very "leaky" and due for replacement). My walk-out basement had very high levels. My next door neighbor's non-walk-out basement, had normal levels. I've not seen a pattern.