ƒ TM The ToxGuide is developed to be used as a pocket guide. Tear off at perforation and fold along lines.

Toxicokinetics and Biomarkers/Environmental Sources of Exposure Normal Human Levels Levels ToxGuideTM

General Populations Toxicokinetics Biomarkers ƒ The general population is exposed to ƒ Approximately 50–75% of inhaled ƒ Barium can be measured in bone, blood, for barium through consumption of drinking or is urine, and feces. However, there are no water and food, usually at low levels. absorbed from the respiratory tract. data correlating barium levels in these ƒ Barium sulfate is frequently utilized as a ƒ Approximately <5–30% of acid-soluble tissues with specific exposure levels. benign, radiopaque aid to x-ray diagnosis barium compounds, such as barium ƒ Gastrointestinal disturbances followed by Barium in colorectal and some upper chloride and are hypokalemia, hypertension, and heart gastrointestinal examinations. absorbed. rhythm abnormalities are frequently ƒ Barium and compounds are used in oil ƒ Barium sulfate is extremely insoluble and reported following acute oral exposure to high doses of barium. Ba and gas drilling muds, automotive paints, very little, if any, is absorbed through the stabilizers for plastics, case hardening . steels, bricks, tiles, lubricating oils, and jet CAS# 7440-39-3 ƒ Approximately 90% of the body burden Environmental Levels October 2007 fuel as well as in various types of of barium is contained in the bones and pesticides. Air teeth. ƒ The concentration of barium in ambient ƒ The primary route of excretion from the air is estimated to be <0.05 μg/m3 . U.S. Department of Health and Occupational Populations body is the feces. Sediment and Soil Human Services ƒ Occupational exposure to barium Public Health Service ƒ Barium is found in most soils at primarily occurs in barium mining or Normal Human Levels Agency for Toxic Substances processing industries. concentrations ranging from about 15 to 3,500 ppm and mean values ranging and Disease Registry ƒ In the United States, the geometric mean www.atsdr.cdc.gov concentration of barium in the urine is between 265 and 835 ppm, depending on soil type. approximately 1.5 µg/L. Contact Information: Water Division of Toxicology ƒ Barium concentrations in drinking water and Environmental Medicine typically average 30 μg/L, but can Applied Toxicology Branch average as high as 302 μg/L. 1600 Clifton Road NE, F-32 Reference Atlanta, GA 30333 1-800-CDC-INFO Agency for Toxic Substances and Disease 1-800-232-4636 Registry (ATSDR). 2007. Toxicological

Profile for Barium. Atlanta, GA: U.S. www.atsdr.cdc.gov/toxpro2.html Department of Health and Human Services, Public Health Services.

TM The ToxGuide is developed to be used as a pocket guide. Tear off at perforation and fold along lines.

Chemical and Physical Information Routes of Exposure Relevance to Public Health (Health Effects)

Barium is an alkaline earth ƒ Inhalation – generally limited to Health effects are determined Health Effects occupational exposure. by the dose (how much), the ƒ Based on limited human and animal data, ƒ Barium is a silvery-white metal that ƒ Oral – Primary route of exposure for duration (how long), and the the respiratory tract is the most sensitive primarily occurs in nature as barite general population. Some foods, such as route of exposure. target following inhalation exposure. Brazil nuts, seaweed, fish, and certain (barium sulfate) and (barium ƒ The solubility of the barium compound plants, may contain high amounts of carbonate) . in the gastrointestinal tract is an barium. Minimal Risk Levels (MRLs) ƒ Barium compounds are , existing as important factor affecting the Inhalation powder or crystals. ƒ Dermal – minor route of exposure. development of adverse health effects. Compounds such as barium chloride and ƒ No acute-, intermediate- or chronic- barium carbonate are generally expected Barium in the Environment duration inhalation MRLs were derived for barium. to be of greater health concern than ƒ Barium enters the environment naturally Oral insoluble barium compounds (notable through the weathering of rocks and barium sulfate) which are generally minerals. Anthropogenic releases are ƒ No acute-duration oral MRL was derived nontoxic to humans. primarily associated with industrial for barium. ƒ The predominant effect following processes. ƒ An MRL of 0.2 mg barium/kg/day has ingestion of high doses of barium is ƒ In the atmosphere, barium is likely to been derived for intermediate-duration hypokalemia which can result in present in particulate form and is oral exposure (15–364 days). ventricular tachycardia, hypertension primarily removed by wet and dry ƒ An MRL of 0.2 mg barium/kg/day has and/or hypotension, muscle weakness, deposition. been derived for chronic-duration oral and paralysis. ƒ In aquatic media, barium is likely to exposure (≥1 year). ƒ Animal studies suggest that the kidney is precipitate out of solution as an insoluble a sensitive target following long-term salt. exposure to low levels of soluble barium ƒ Barium is not very mobile in most soil compounds. systems due to the formation of water- insoluble salts and the inability of barium Children’s Health to form soluble complexes with fulvic and humic acids. ƒ The available data are insufficient to determine whether children may be more ƒ Barium has the potential to susceptible to barium toxicity than adults. bioconcentrate in marine animals and plants and in some terrestrial plants such ƒ There are some data suggesting that as legumes, forage plants, Brazil nuts, and children may absorb more barium than mushrooms. adults.