BaSO4 and Ba ions

I know barium ions are supposed to be highly poisonous, so how come it's safe to use them with Sulfate ion when they X-ray someone's digestive system?
I know the Sulfate keeps the Barium from ionizing because it is insoluble, but couldn't something like an acid or more reactive ion replace the Sulfate and free the barium ion?
Why isn't this a problem?


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The toxicity of barium

The toxicity of barium compounds depends on their solubility.
The more soluble forms are more toxic than the insoluble forms.
Barium sulfate is very insoluble in water and other potential solvents.

To add to this BaSO4 is administered for X-rays as a slurry with dilute Na2SO4, which makes the compound even more insoluble, due to the common ion effect. [Common ion effect states that any ionic salt is less soluble in the presence of a common ion].

After an X-Ray patients are advised to drink plenty of water to help flush the insoluble salts out of their body.

Because there are no barium ions in BaSO[sub]4[/sub]; the stuff is so intensely insoluble that the amount of Ba[sup]+2[/sup] in neglible. If you tried an enema with BaCl[sub]2[/sub] you would have to call the coroner immediately.

still sonfused

It's insoluble in water, but what about all the lovely acids and catalysts we have in our digestive tracts?
I would think that at least one of them would have an impact on similar insoluble salts.
What if its even a small ammount of solubility?
How do we know its a small ammount that's BAD and not a small ammount that's never going to ever matter? I thought that even a small ammount would be bad enough that they wouldn't have people drinking it so regularly for x-rays. :?

The acid in the stomach is essentially HCl; BaSO4 is insoluble in that as well; a common lab demonstration is mixing BaCl and Na2SO4; the BaSO4 settles to the bottom and you end up with salt water; the insolubility of BaSO4 is enormous and the proof is that people with barium enemas don't die whereas the long-term effects of radiation do cause people to die; my father's broken leg was x-rayed in all stages of healing; he had hundreds of x-rays taken; the hair on his leg didn't regrow and he died of multiple myeloma when I was 20 and he 51; there are no similar stories about people with barium enemas.

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