Mainly transported by water, arsenic is widely distributed throughout the ecosystem by weathering of rocks, burning of fossil fuels, smelting of ores and manufacturing. Arsenic exposure can cause a variety of adverse effects. The severity of the effect depends on the level of exposure. Acute high-dose oral exposure to arsenic typically leads to gastrointestinal irritations accompanied by difficulty in swallowing, thirst, abnormally low blood pressure, and convulsions. Death may occur from cardiovascular collapse at very high doses.
Evidence exists that long-term exposure to high arsenic levels increases the risk of cancer.
When exposure is by inhalation, the primary effect is increased risk of lung cancer. When exposure is by ingestion, the clearest effect is increased risk of skin cancer. For most people, the most significant route of exposure to arsenic is through food. It is a normal component of the diet. Ingestion of drinking water can be a source of arsenic exposure.