In small amounts these are harmless and in some cases even beneficial to health. Amounts over drinking water standards may have serious health effects. The primary drinking water standard for arsenic is 0.05 milligrams per liter. Arsenic accumulates in body tissues. In high concentrations, arsenic can damage the digestive tract, heart and circulation.
Studies suggest that arsenic is associated with skin cancer.
Studies also indicate that arsenic in small amounts may be an essential element for normal human development. Arsenic contamination of water is most often caused by leachate from solid waste landfills, or from use of pesticides. The primary drinking water standard for barium is 1.0 milligrams per liter. Small doses are not harmful. Large amounts can cause increased blood pressure, nerve damage or cardiovascular disease.