Barium

Barium is a silver-white metal that makes up 0.05% of the earth's crust. Two barium compounds - barium sulfate and barium carbonate - are often found in underground deposits. Very small amounts of naturally occurring barium are sometimes present in food and drinking water.

Groundwater erosion of sedimentary rocks is the primary source of naturally occurring barium in drinking water. However, barium can be released into the air and penetrate into groundwater due to industrial processes and other human activities.

Naturally occurring levels of barium are very low. The air that most people breathe contains less than 0.0015 parts of barium per billion parts of air (ppb). Air around factories that release barium compounds has roughly 0.33 ppb - or less - of barium. Most surface water and public water supplies contain less than 0.38 ppb. The soil contains 0.1-0.6 ppb. All of these levels are safe.

Some foods, such as Brazil nuts, seaweed, fish, and certain vegetables, may contain higher amounts of barium. Very small amounts of barium in the diet may contribute to good health.

How is barium used?

Barium and barium compounds are used for many commercial processes. Barium sulfate is mined and used in oil and gas production, medical procedures, and the manufacture of paints, bricks, tiles, glass, and rubber. Other barium compounds are used in the manufacture of ceramics, pesticides, and oil and fuel additives. In addition, physicians often ask patients to swallow a barium compound solution as part of certain medical test procedures.

Do electric utilities release barium into the environment?

Yes. Coal and oil contain a number of different trace elements, sometimes including small amounts of barium. When coal and oil are burned to generate electricity, an ash is produced which contains more than 99% of their barium content. The amount of barium found in coal ash ranges between 0.05-6.0 ppb.

Electric utilities manage coal ash in a variety of ways in order to minimize impacts to human health and the environment. Some ash is disposed of in specially designed ponds, landfills, abandoned mines or quarries. Studies have found that the concentration of barium in water samples collected near ash disposal sites falls well within allowable limits for drinking water.

In many cases, coal ash is recycled to products for commercial uses, such as concrete for highway roadbeds and embankments and other construction material.

The ash that is not captured is carried into the air in small particles. These particles eventually settle on land and water.

How could I be exposed to barium?

Barium can enter the body in three ways:

• consumption of certain foods and/or drinking water;
• inhalation of airborne barium compounds; and
• direct skin contact with material containing barium (very rare).

The amount of barium in food and water supplies poses little or no health concern. In fact, the human body requires a certain level of barium to maintain good health. Barium releases from electric utilities are too low to cause adverse health effects.

Exposure to barium is only a hazard for individuals employed in industries that manufacture or use barium compounds. Workers in these situations could breathe air that contains high concentrations of barium compounds. Breathing in large amounts of barium dust can cause abdominal cramps, nausea, and vomiting. Swallowing large amounts of barium can cause breathing trouble, hypertension, irregular heart rhythm, paralysis, or death.

What does EPA say?

Federal agencies regulate barium releases in order to protect human health and the environment. EPA has established a maximum level of 1,100 ppb of barium in drinking water. EPA also has said that an average-sized adult exposed to 1,500 ppb every day for 70 years will not experience adverse health effects.

Where can I get more information?

• Electric Power Research Institute
  3412 Hillview Ave.
  P.O. Box 10412
  Palo Alto, California 9430
  phone (650)855-2000.
  
  
• Full-Scale Field Evaluation of Waste Disposal from Coal-Fired Electric Generating Plants, Vol. III, Appendices
  A & B, U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory, 1985.
  
  
• Integrated Risk Information System, U.S. Environmental Protection Agency.
  
  
• Report to Congress: Wastes from the Combustion of Coal by Electric Utility Power Plants, U.S. Environmental Protection Agency, 1988.
  
  
• Toxicological Profile for Barium and Compounds, U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substance and Disease Registry, 1992.
  
  
• 1995 Toxics Release Inventory Public Data Release, U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, 1997.