Radiation from ceramic tiles

How much radiation would be too much from ceramic tiles?

When I put the counter on a stack of tiles I get 1400-1600 counts (gamma) per hour or about 0.15 microsieverts/hour. A single tile is less. Normal background here is 0.07 microsieverts/hour.

I'll have to do some more tests.

Radiation from tiles

The Health Physics Society "Ask the Experts" page has a couple of answers that are relevant to your question about the radioactivity of tiles:

Mark [BRAWM Team Member]

Apples and oranges...

How much radiation would be too much from ceramic tiles?

When I put the counter on a stack of tiles I get 1400-1600 counts (gamma) per hour or about 0.15 microsieverts/hour. A single tile is less. Normal background here is 0.07 microsieverts/hour.

Unfortunately, this is an "apples and oranges" question. The number of counts per unit time gives one an idea of the "activity" of the radioactive material, which is the rate at which the material is undergoing radioactive decay. The activity is measured in the older unit "Curie" or the SI unit of "Becquerels".

When you talk about "Sieverts" or "microSieverts"; you are talking about "dose equivalent". This is a measure of the amount of radiation damage. It is the product of the "dose" which is how much energy is absorbed per unit mass ( measured in "rads" or "Grays" ) and a "quality factor" which tells you how damaging a particular radiation type is.

BRAWM member Mark Bandstra makes this point in the following thread in a post entitled, "Radioactivity is not dose":


The estimates of releases are in terms of radioactivity (Becquerels). Radioactivity is not dose. Dose (Sieverts) depends on how someone is exposed to radioactivity. Dose cannot be calculated just based on the amount of radiation released.

I'm sorry that I can't give you a simple answer. However, you are discovering that much of our natural world is radioactive, and the largest source of radiation exposure is Mother Nature. Is now, and always has been.

Sure, all radioactivity

Sure, all radioactivity originally resulted from mother nature, but once we start dredging it out of the ground and plastering our homes with it, it's another story. (Once we start enriching it and causing fission reactions, holy COW is that another BOOK!) Like many things that exist in nature, radioactivity is toxic to humans in any amount. Not everything that is in nature should be on our walls, or holding our foodstuffs.

I've been doing some reading, and like granite, ceramics, glazes on ceramics, clays, enamel and porcelain tend to have uranium in them if they are 'hot,' and that means they emit radon. Radon isn't good for you, AT ALL, and we get more than enough from the ground as it is.

And a whole lot more ceramic pottery seem to be hot than just this fiestaware stuff from back in the day -- though I get the impression that that stuff was really steamin' hot! I have NO fiestaware, but I realized that I have to go through each of my pieces one by one - some are at my home's background, some slightly elevated, but many more than I thought seem to be WAY above.

Anyway, that said, your counts are per hour with the tiles, correct? That doesn't seem very high to me, because CPM are in the 20's. I've got a toilet with a CPM the 80's-90's, and a mug like that too. It's not an old fiestaware mug - it's new. I think I'll retire it. Dunno what to do about the toilet. Stainless steel upgrade time? Luckily, my tiles are cool.

Caveat about the relative safety of your tiles: you say gamma. Does that mean your detector can account for gamma only? I'm using a broad spectrum radioactivity detector (alpha through x-ray) which means that my detector will always tend to show higher CPM than if it could only detect gamma (I don't know about 4 times as much, though). I say, as a comparison with your tiles, check your porcelain throne.

Latest research from Lawrence Berkeley National Laboratory

Like many things that exist in nature, radioactivity is toxic to humans in any amount.

The latest research from Lawrence Berkeleley National Laboratory published in the prestigious Proceedings of the National Academy of Sciences suggests the above may not be true.



“Our data show that at lower doses of ionizing radiation, DNA repair mechanisms work much better than at higher doses,” says Mina Bissell, breast cancer researcher with the Life Sciences Division. “This non-linear DNA damage response casts doubt on the general assumption that any amount of ionizing radiation is harmful and additive.”

Dustbin "science"

I can't believe anyone would find that piece of dustbin "science" credible. Talk about drawing ridiculous conclusions from the data. Didn't they learn not to do that in graduate school -- scratch that -- undergrad? Is Research Ethics an optional course these days?

This is the kind of thing that gives science a bad name.

Here is a succinct refutation of that nonsense conclusion from that biased bit of tripe:

The game is over in terms of keeping the lid on low-dose ionizing radiation effects. The public is no longer so naive.

You don't trust a peer

You don't trust a peer reviewed paper but you trust some random guys you tube video? I am pretty sure I learned not to trust everything on the internet when I was 6.

You're right, if someone

You're right, if someone makes a sound statement and fails to point out his socially-sanctioned, quasi-relevant pedigree while doing so, I best ignore it, otherwise, I "trust everything on the internet." Your double ad hominem towards both the maker of the video and myself is much a sounder approach toward objective truth than would be discussing the topic at hand.

As to blind faith in all those who consider themselves scientists, (by the way, the Mangano US deaths from Fukushima study was peer-reviewed, wild guess that you don't feel so great about peer-review there, huh?) Having been in the science game for over a decade (and don't kid yourself, dear readers, it is very much a game), it must be shocking that I can differentiate biased propaganda far overstepping reasonable conclusions drawn from in vitro data, from good quality science.

It must also be shocking that with the hundreds of scientists I have personally know, and have seen at their best and most PR-appropriate, and also at their worst, most drunken, and most self-loathing, that I have come to the understand that scientist run the gamut of morality, indeed just like every other human!

Moreover, you may be shocked that I deem it fair to say, in every field, they worry about, and are biased due to, the sources of their funding, their chances of tenure, and so on -- for they too have mortgages to pay. Such temptation taints work of even those who mean well (here you will find common the refrain "I don't like to think about it" and "I just have to hope my work isn't used that way" (avoidance of full awareness of personal responsibility) -- hey, who ever told you science was going to be easy, or that you would not be ethically tested every damn day? They lied! But, also keep in mind,not every skillful individual in the field means well. They may not necessarily mean harm - they may not care either way. If you are a scientist, and don't care about the social impact of your work either way, but only about the bacon you bring home, you WILL be more influenced by grant monies than scientific objectivity, and you WILL start making ridiculous, extraordinarily overreaching claims such as was made by Costes et al. You may even ignore the fact that the bulk of the literature indicates the opposite conclusion - again, just like Costes et al.

You don't play this game for so many years without being able to smell the folks like Costes et al. a mile away. I am in a different field and I am happy to report that I have no financial conflict of interest whatsoever in sniffing out rats in this field. As for the poster here promoting them, I wouldn't be surprised if you shared at least the same cocktail circuit with them -- am I wrong? If you deny any association publicly while muttering to yourself privately "lucky guess, but it's not like it matters anyway - I WOULD feel the same way if I was in a different field entirely," what would it take to give you pause enough to go through again your rationale for your enthusiastic cheerleading of this piece of very poor (and more concerning, alarmingly dangerous) 'science'?


This was very helpful as I've been wondering about the radioactivity of kitchen ceramics and pottery. Do you mind telling me what detector you're using and where you got it? I don't know how practical it is to undertake this on my own...
Thanks much!

The "inspector alert"

The "inspector alert" (international medcom).