I hope you are nor thinking of poisoning yourself or anybody else!

Here is what I found after some web search:
Arsenic in the forms in which it normally can be found in foods, like the organically bound arsenic of shrimp, is easily absorbed and rapidly eliminated in the urine. The more toxic compounds, like arsenic trioxide, is well absorbed and excreted rather slowly. The symptoms of acute arsenic poisoning are nausea, vomiting, diarrhea, burning of the mouth and throat, and severe abdominal pain.

Chronic exposure to smaller, perhaps continued doses, results in weakness, muscular aching, skin abnormalities, and pigmentation within the fingernails.

On the cellular level, scientists believe that arsenic affects the mitochondrial enzymes and messes up respiration. The mitochondria accumulate arsenic which in turn stops a critical reaction necessary for continued cellular oxidation. It is important to remember that arsenic is both an acute and chronic systemic toxin and a carcinogen. Some arsenic is, however, thought to be needed by our body. So,as with all substances is that it is "the dose makes the poison".

Retained arsenic (as from arsenic trioxide) is concentrated in hair and fingernails. Hair samples can be analyzed for arsenic and the arsenic can be easily detected even some time after exposure.

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