Arsenic Compounds and Their Uses

Study Notes

Arsenious oxide (arsenic trioxide) is the most toxic form of arsenic, with no taste or smell, and is sparingly soluble in water.
It is used in fruit sprays, sheep-dips, weed-killers, insecticides, rat poisons, flypapers, calico-printing, wallpapers, and as a mordant in dyeing.

Copper arsenite (Scheele's green) and copper acetoarsenite (Paris green or emerald green) are used as coloring agents in substances, including confectionary.

Arsenic can be found naturally in soil, water, and some sea fish (mussels, prawns).
High arsenic content in soil and subsoil water can cause endemic toxicity.

Arsenic interferes with cellular respiration by uncoupling mitochondrial oxidative phosphorylation.
It combines with sulfhydryl groups of mitochondrial enzymes, inhibiting cellular glucose uptake, gluconeogenesis, fatty acid oxidation, and acetyl CoA production.
Locally, arsenic causes irritation of mucous membranes, and remotely, depression of the nervous system.

Arsenic is a carcinogenic substance linked to lung, skin, and bladder carcinoma in populations with multiple exposures.

Arsenic is absorbed orally through the GIT, skin, and lungs, and can also be absorbed parenterally.
It is present in almost all tissues, with the highest concentration found in the liver, kidneys, and spleen.
Arsenic is excreted mainly by the kidneys, but also through feces, bile, sweat, milk, nails, and hair.

Symptoms usually appear within 1 hour of ingestion, but may be delayed if arsenic is taken with food.
GIT symptoms include sweet metallic taste, nausea, persistent vomiting, burning in the mouth and throat, difficulty in swallowing, and garlic odor in breath.
Other symptoms include intense thirst, pain in the esophagus and abdomen, purging accompanied by tenesmus, and pain and irritation around the anus.
Renal symptoms include oliguria, uremia, albuminuria, red cells, and casts, as well as pain during micturition.
CVS symptoms include hypotension, circulatory collapse, ventricular tachycardia, and fibrillation.
Hepatic symptom includes fatty infiltration.
MS symptoms include pain in limbs and weakness.
CNS symptoms include headache, vertigo, and hyperthermia.