To give you just 1 exmaple of the ones we have seen.....

Customer put a bowl full of Vinagar on the counter, he then put and old shower head in the bowl causing the Vinagar to spill over the sides of the bowl. This was left over night, the next day he day a ring the size of the bowl that had discolored and etched the counter. Then they called us and we fixed it .

Okay, vinegar and countertop materials, including granite.  You are going to wish this wasn't brought up.  If you want the short version, skip down to the bottom.

Here is an email from a email based forum send by an internet friend of mine, a canadian that is a radiological expert, especially the measurement of same.

"From: Kai Kaletsch

Sent: Thursday, July 31, 2008 6:31 AM
To: al gerhart
Cc: Dan W McCarn
Subject: Re: [ RadSafe ] Radon Travel in Granite

Uranium is usually pretty mobile and either acids of bases will leach it.
Even if you just dig up the ore and leave it sitting outside, the oxygen and
water are enough to leach it and you will find a yellow crust on the bottom
of the rocks or a yellow stain leading to the floor drain after a few years."


And another friend, one with which I have had some interesting phone calls from, Dan McCarn, an Uranium Geologist.  Skim it, don't try too hard to understand everything.  Dan has a PhD. in geology and isn't afraid to educate you.

"Dear Group, Kai & Al:

Back to basics, and a little simplified, but what the heck!

Primary mineralized uranium is usually the reduced species uraninite, UO2,
also known as pitchblende.  When uraninite comes in contact with oxidizing
groundwater, the redox state changes rapidly from +4 to +6.  Normally,
oxidized uranyl species UO2 +2 reacts with groundwater to form the highly
soluble solid species UO2(OH)2 H2O (Schoepite) and then to form carbonate
anionic aqueous species e.g. UO2(CO3)2 -2 or UO2(CO3)3 -4 because of the
high abundance of bicarbonate (HCO3-) in oxidizing natural groundwater
conditions.  This includes the range of pH from about 6.2 – >10.  Below a pH
of 6.2 the neutral aqueous species, UO2(CO3)2 0 forms.  So, at a pH of 7,
the dominate form of aqueous uranyl species is UO2(CO3)2 -2.  When solution
mining, this species is concentrated in anion exchange resins (bumps Cl -1
off) and the pH is maintained close to 7 to optimize the bicarbonate
complexation of uranyl.

How much concentration? Up to several hundred mg/L U concentration depending
on the bicarbonate ion concentration.  Sometimes NaHCO3 is added to enhance
the groundwater's ability to complex uranium.  Because the kinetics are
quite good, the reaction goes pretty fast.

Note: rain water, equilibrated to atmospheric CO2 and O2 is easily able to
rapidly mobilize uraninite (UO2) forming quite a nice, mildly acid leaching
solution of pH = about 5.6.  As a geologist, this is quite exciting, and I
can only add, "Yippee".


Dan ii"

What Dan basically said was that he agreed with Kia, either an acid like vinegar or a A
alkaline liquid  like Tea or some alkaline water from the faucet will leach the uranium out of a granite countertop.


And a last quote from a personal email from Kai

"

" I would not say that. I would not use 0.25% U as a countertop. I would not take any special measures for normal granite (~10 ppm). If I did have to eat off a 0.25% Uranium countertop, I don't know if I would want my cleaner to leave the Uranium in the material, or remove it from the top surface. I would probably see if a sealer could be applied."

At the time, Kai was under the impression that granite sealer was a thick coating of some sort, not what is normally used with the top scrubed clean before it dries.


So in short, do not use vinegar of any sort, although if you understand what Dan was saying, was that a mildly acidic 5.6 solution will leach uranium easily, but vinegar is around 2.5 pH. 

The pH scale is logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the next higher value, so vinegar at 2.5 is 1,000 times more acidic than normal rainwater at 5.6 pH.

So vinegar will leach a lot more uranium than normal water will, and as Dan said, rainwater "easily able to
rapidly mobilize uraninite ".  Indeed, most uranium ore beds were formed by rainwater leaching uranium compounds out of granite rock.

"The high toxicity of soluble compounds of uranium is largely manifest in irreversible kidney damage. Blood disorders have also been observed in uranium industry workers."

Toxicity of Uranium

Don't you think it would be better to ban the high Uranium content granites?

Geez, those experts also said water and oxygen caused the leaching.  Best take a long drink and a deep breath.