Barium

Barium is a "silvery-white metal which exists in nature only in ores containing mixtures of elements." Barium forms barium compounds by combining with elements like sulfur, carbon, or oxygen.

Uses
The oil and gas industries use barium compounds to make drilling mud, a substance that lubricates the drill bit to make drilling through rock easier. Barium compounds are also used to make paint, bricks, ceramics, glass, and rubber. In medicine, barium sulfate is used to perform medical tests and to take x-rays of the gastrointestinal tract.

Barium in the Environment
Activities like mining, refining, burning coal and oil, and producing barium compounds release barium into the air. Once in the environment, barium's persistence depends on the form it is in. Some barium compounds like barium sulfate and barium carbonate do not dissolve well in water and can last a long time in the environment. Other barium compounds, including barium chloride, barium nitrate, or barium hydroxide, dissolve easily in water. These compounds typically do not last long, as the barium quickly combines with sulfate or carbonate to become barium sulfate or barium carbonate, respectively. Fish and other aquatic organisms can accumulate barium.

In Sewage Sludge
In the Targeted National Sewage Sludge Survey, a 2009 test of 84 samples of sewage sludge from around the U.S., the EPA found barium in every sample in concentrations ranging from 75.1 to 3,460 parts per million.

Human Exposure
Humans are exposed to barium through small amounts in food, water, or air. Exposure will increase if one lives in an area with unusually high levels of barium in the drinking water, works in a job that involves barium production or use, or lives or works near waste sites where barium is disposed of.

Health Effects
The health effects of barium depends on which compound one is exposed to and how well that compound dissolves in water or in the stomach. Barium compounds that do not dissolve, like barium sulfate, well are "not generally harmful." However, short term exposure to barium through drinking water has resulted in gastrointestinal disturbances and muscular weakness. Short term exposure from food and water can result in vomiting, abdominal cramps, diarrhea, breathing difficulties, increased or decreased blood pressure, numbness around the face, and muscle weakness. At high levels, barium can result in changes in heart rhythym, paralysis, and possibly death. In animal studies, long term exposure to barium resulted in kidney damage, weight loss, and sometimes death.

Related SourceWatch articles

 * Biosolids
 * Sewage sludge
 * Food Rights Network

External resources

 * Agency for Toxic Substances & Disease Registry, ToxFAQs for Barium