Most arsenic compounds are white or colorless powders that do not evaporate. They have no smell, and most have no special taste. Thus, you usually cannot tell if arsenic is present in your food, water, or air.
Inorganic arsenic occurs naturally in many kinds of rock, especially in ores that contain copper or lead. The arsenic enters the air as a fine dust when copper or lead-containing ores are heated at smelters to get the copper or lead. Smelters collect this dust and purify the arsenic for several uses. The main use was as a preservative for wood to make it resistant to rotting and decay, often CCA wood. However, recently this type of wood has often been replaced in residential construction by wood treated with a safer product.
Arsenic is also used to make several types of insect killers and weed killers. Gallium arsenide (GaAs) is used in integral components of discrete microwave devices, lasers, light-emitting diodes, photoelectric chemical cells, and semiconductor devices. The use of arsine gas (AsH3) in the production of semiconductors is also expected to increase, although substitutes of lower toxicity have recently been used. A source of arsine exposure is accidental release during manufacture, transport, or use of the gas.
Breathing high levels of inorganic arsenic can give you a sore throat or irritated lungs. Ingesting very high levels of arsenic can result in death. Exposure to lower levels can cause nausea and vomiting, decreased production of red and white blood cells, abnormal heart rhythm, damage to blood vessels, and a sensation of “pins and needles” in hands and feet.
Ingesting or breathing low levels of inorganic arsenic for a long time can cause a darkening of the skin and the appearance of small “corns” or “warts” on the palms, soles, and torso. Skin contact with inorganic arsenic may cause redness and swelling.