Tissue barium

The fluid and protein shift into the abdomen (called third-spacing) may be so dramatic that circulating blood volume is decreased, which causes decreased cardiac output and hypovolemic shock. Accompanying fever, vomiting, or diarrhea may worsen the fluid imbalance. A reflex sympathetic response, manifested by sweating, tachycardia, and vasoconstriction, may be evident. With an inflamed peritoneum, bacteria and endotoxins are absorbed easily into the bloodstream (translocation), and this may result in septic shock. Other foreign substances present in the peritoneal cavity potentiate peritonitis, notably feces, dead tissues, barium, mucus, bile, and blood. 

The barium content of human tissues is dependent on age. For example, in adults the liver contained barium levels of 4-20 mg kg dry matter, whereas in children the typical liver barium content was much higher, at 144 mg kg The majority of tissue barium is accumulated in the skeleton, with typical adult levels ranging from 16 to 95 mg kg dry matter. Very high barium contents were also determined in the prostate gland of children, with up to 1.3gkg dry matter in infants (Jaritz 1998). Other sources have described lower levels of barium in human tissues however... 

Strontium levels/Tissue Barium levels/Tissue Reference... 

In other applications of CT, orally administered barium sulfate or a water-soluble iodinated CM is used to opacify the GI tract. Xenon, atomic number 54, exhibits similar x-ray absorption properties to those of iodine. It rapidly diffuses across the blood brain barrier after inhalation to saturate different tissues of brain as a function of its lipid solubility. In preliminary investigations (99), xenon gas inhalation prior to brain CT has provided useful information for evaluations of local cerebral blood flow and cerebral tissue abnormalities. Xenon exhibits an anesthetic effect at high concentrations but otherwise is free of physiological effects because of its nonreactive nature. 

The average adult human body contains 22 mg Ba, of which 93% is present in bone (47). The remainder is widely distributed throughout the soft tissues of the body in very low concentrations. Accumulation of barium also takes place in the pigmented parts of the eyes. 

Why are barium- and iodine-based materials selected for contrast media The production of X-ray images depends on the differences between the X-ray absorbing power of various tissues. This difference in absorbing power is called contrast and is directly dependent on tissue density. To artificially enhance the ability of a soft tissue to absorb X-rays, the density of that tissue must be increased. The absorption by targeted soft tissue of aqueous solutions of barium sulfate and iodized organic compounds provides this added density through the heavy metal barium and the heavy nonmetal iodine. 

Barium sulfate is a radiopaque or contrast agent that blocks the transmission X-rays to help physicians see any special conditions that may exist in an organ or that part of the body where the contrast agent is localized. The areas in which radiopaque agents are located will appear white on X-ray film, creating the needed distinction, or contrast, between one organ and other tissues. How can the toxicity of the barium ion be controlled to provide this necessary radiopaque function ... 

Nixon277 compared atomic absorption spectroscopy, flame photometry, mass spectroscopy, and neutron activation analysis as methods for the determination of some 21 trace elements (<100 ppm) in hard dental tissue and dental plaque silver, aluminum, arsenic, gold, barium, chromium, copper, fluoride, iron, lithium, manganese, molybdenum, nickel, lead, rubidium, antimony, selenium, tin, strontium, vanadium, and zinc. Brunelle 278) also described procedures for the determination of about 20 elements in soil using a combination of atomic absorption spectroscopy and neutron activation analysis. 

British chemist Sir Humphry Davy Soft, reactive, abundant metal as barium sulfate, it blocks transmission during diagnostic X rays to highlight organs and other tissue. 

There is no routine medical test to determine whether you have been exposed to barium. Doctors can measure barium in body tissues and fluids, such as blood, bones, urine, and feces, using very complex instruments. This is normally done only for cases of severe barium poisoning and for medical research. More information on testing for barium exposure is found in Chapters 2 and 6. 

Musculoskeletal Effects. After accidental exposure to a large amount of barium carbonate powder by acute inhalation, a 22-year-old factory worker developed progressive muscle weakness and paralysis of the extremities and neck (Shankle and Keane 1988). X-ray analysis of the bones and skeletal muscles of the pelvis and thighs of workers chronically exposed to barium carbonate dust revealed no apparent build up of barium in these tissues (Essing et al. 1976). No studies were located regarding musculoskeletal effects in animals after inhalation exposure to barium. 

Humans can be exposed to barium in the air, water, or food. Numerous studies exist that discuss the distribution of barium in the human body, but they do not always specify route of exposure. It is presumed that the majority of the barium intake is from the oral route. Barium occurs mostly (over 93%) in the bones and teeth of humans. Very little is found in blood plasma or soft tissues but, when it is detected in the organs, it is found in the eye, lungs, skin, and adipose tissue in humans at less than 1 % of total body weight (Schroeder et al. 1972). This information is supported by a number of studies (Bauer et al. 1957 Losee etal. 1974 Miller et al. 1985 Moloukhia and Ahmed 1979 Sowden 1958 Sowden and Stitch 1957 Sowden and Pirie 1958). 

Barium is not metabolized in the body, but it may be metabolically transported or incorporated into complexes or tissues. 

Acute intravasation of barium sulfate into the circulatory system of an adult female patient following a barium enema procedure caused the compound to be deposited in blood vessels throughout the body, including the lungs, and resulted in respiratoryfailure (Cove and Snyder 1974). Acute parenteral administration of barium compounds to animals has been shown to result in paralysis of the respiratory muscles (Roza and Berman 1971). Similar respiratory paralysis is frequently encountered in cases of acute exposure in humans and animals by ingestion or inhalation. Intratracheal administration of barium sulfate into rat lungs produced a mild inflammatory reaction (Huston et al. 1952). Barium sulfate could not be removed by either polymorphonuclear leukocytes or monocytes. A tissue reaction followed however, no fibrosis was observed. Since this mode of entry is similar to inhalation, these results may be significant for cases of inhalation exposure. 

Two case studies of acute intrusion of barium sulfate into the peritoneal space during barium enema examination of four men showed barium sulfate caused an acute inflammatory tissue response (Kay 1954 Yamamura et al. 1985), and in one case resulted in formation of a fibrous granuloma (Kay 1954). This is an extremely rare mode of entry and not of significant concern for individuals exposed at a hazardous waste site. Increased fluid accumulation in the intestinal lumen of rats was observed after intraperitoneal injection of barium chloride (Hardcastle et al. 1983b, 1985) however, this observation is not significant for individuals exposed at hazardous waste sites because of the route of exposure and because there has been no documentation of this effect occurring in humans following normal exposure routes. 

One in vitro study on rat renal tissue homogenate showed barium weakly inhibited the sodium-potassium-adenosine triphosphatase enzyme system (Kramer et al. 1986). A second study on mouse kidney tubules showed barium chloride could depolarize the membrane and inhibit potassium transport (Volkl et al. 1987). A similar defect in cell membrane transport in humans could be responsible for the renal involvement observed in some cases of acute barium poisoning. 

Another consideration for estimating the toxicity of barium, as well as other compounds, is that the toxicity may well be altered by interactions with other toxicants. Specifically, barium would be expected to have reciprocal interactions with other trace metals found in the environment and in human tissues (Berggren et al. 1983 Foster et al. 1977 Jaklinski et al. 1967 Roza and Berman 1971 Schott and McArdle 1974). Considerations of these interactions should be made when designing future tests of barium and other compounds. 

Biomarkers of Exposure and Effect. There are no established biomarkers of exposure for barium. Analytical methods exist for measuring barium in blood, urine, feces, and biological tissues (Mauras and Allain 1979 Schramel 1988 Shiraishi et al. 1987) however, there are no data correlating levels of barium in these tissues and fluids with exposure. 

In a study of the barium content of the major human organs and tissues, the total body content of barium for a 70-kg adult male was estimated to be about 22,000 pg (ICRP 1974 Schroeder et al. 1972). Ninety-three percent of this barium was found in bone and connective tissue. Large amounts of the remaining 7% existed in fat, skin, and lungs (ICRP 1974 Schroeder et al. 1972). 

Cuddihy RG, Griffith WC. 1972. A biological model describing tissue distribution and whole-body retention of barium and lanthanum in beagle dogs after inhalation and gavage. Health Phys 23 621-633. 

Kay S. 1954. Tissue reaction to barium sulfate contrast medium. AMA Arch Pathol 57 279-284. 

Sowden EM. 1958. Trace elements in human tissue 3. Strontium and barium in non-skeletal tissue. Biochem J 70 712-715. 

Sowden EM, Pirie A. 1958. Barium and strontium concentrations in eye tissue. Biochem J 70 716-717. 

Sowden EM, Stitch SR. 1957. Trace elements in human tissue 2. Estimation of the concentrations of stable strontium and barium in human bone. Biochem J 67 104-109. 

The forensic scientist employed in the analysis of specimens for metal concentrations is involved generally in two main areas of investigation. The first is in the determination of toxic metals in biological tissue in order to ascertain the cause of death or injury (homicidal or suicidal) in suspected poisoning cases. The second is to compare certain characteristic trace element concentrations in materials found at the scene of the crime with the same type of material found in the possession of the accused. A special case of this second approach is in the analysis of the elements barium,... 

Solubility is important in other ways as well. For example, because the pesticide DDT is fat-soluble, it is retained and concentrated in animal tissues, where it causes detrimental effects. This is why DDT, even though it is effective for killing mosquitos, has been banned in the United States. Also, the solubilities of various vitamins are important in determining correct dosages. The insolubility of barium sulfate means it can be safely used to improve X-ray images of the gastrointestinal tract, even though Ba2+ ions are quite toxic. 

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