Strontium accumulation

Somlyo AV, Somlyo AP 1971 Strontium accumulation by sarcoplasmic reticulum and mitochondria in vascular smooth muscle. Science 174 955-958 Somlyo AV, Bond M, Somlyo AP, Scarpa A 1985 Inositol-trisphosphate induced calcium release and contraction in vascular smooth muscle. Proc Natl Acad Sci 82 5231-5235 Somlyo AV, Horiuti K, Trentham DR, Kitazawa T, Somlyo AP 1992 Kinetics of Ca2+ release and contraction induced by photolysis of caged D-myo-inositol 1,4,5-trisphosphate in smooth muscle the effects of heparin, procaine, and adenine nucleotides. J Biol Chem 267 22316-22322... 

Table 9 compares the contents of heavy metals in the ash of various grass and tree species from the Savanna ecosystems of East Africa. We can see that nickel, barium, and strontium accumulate in the tree organs (twigs), whereas the accumulation of other metals is pronounced in grasses. 

Morgan, J. E., Richards, S. P. G., and Morgan, A. J. (2001). Stable strontium accumulation by earthworms a paradigm for radiostrontium interactions with its cationic analogue, calcium. Environ. Toxicol. Chem. 20, 1236-1243. 

Lagged E, Akron K, Fonyo A. 1979. The inhibitor-sensitivity and pathways of uptake during calcium and strontium accumulation in liver mitochondria. FEBS Lett 107(l) 205-208. 

Somlyo AV, Somlyo AP. 1971. Strontium accumulation by sarcoplasmic reticulum and mitochondria in vascular smooth muscle. Science 174 955-958. 

Somlyo AV, Somlyo, AP (1968b) Electromechanical and pharmacomechanical coupling in vascular smooth muscle. J Pharmacol Exp Therap 159 129-145 Somlyo AV, Somlyo AP (1971) Strontium accumulation by sarcoplasmic reticulum and mitochondria in vascular smooth muscle. Science 174 955-958. 

In other cases where the radioactive material is released, it can he deposited upon environmental surfaces or skin. It could also he inhaled or ingested. The radioactive material on skin and environmental surfaces can usually he washed away, but the close contact with skin may give high doses of radiation to the skin from those isotopes that emit alpha and beta radiation. When radioactive material is inhaled or ingested, it continues to emit radiation and gives the internal areas of the body exposure. If the radioactive material has a chemical affinity for a particular organ of the body, it may accumulate there and selectively irradiate that particular organ. Examples are radioactive iodine (accumulates in tlie thyroid), radioactive cesium (accumulates in the liver), or radioactive strontium (accumulates in bone). 

Strontium is transferred from blood to the interstitial fluid to the same extent as calcium, but intracellular penetration appears to be limited [68,69]. In biological membranes, it has the unique capacity that it can replace calcium even at sites highly specific for calcium [70]. Inside the cell, strontium accumulates, among others, in the mitochondria to levels of 2.5 p,mol strontium/mg mitochondrial protein [71]. 

Half-lives span a very wide range (Table 17.5). Consider strontium-90, for which the half-life is 28 a. This nuclide is present in nuclear fallout, the fine dust that settles from clouds of airborne particles after the explosion of a nuclear bomb, and may also be present in the accidental release of radioactive materials into the air. Because it is chemically very similar to calcium, strontium may accompany that element through the environment and become incorporated into bones once there, it continues to emit radiation for many years. About 10 half-lives (for strontium-90, 280 a) must pass before the activity of a sample has fallen to 1/1000 of its initial value. Iodine-131, which was released in the accidental fire at the Chernobyl nuclear power plant, has a half-life of only 8.05 d, but it accumulates in the thyroid gland. Several cases of thyroid cancer have been linked to iodine-131 exposure from the accident. Plutonium-239 has a half-life of 24 ka (24000 years). Consequently, very long term storage facilities are required for plutonium waste, and land contaminated with plutonium cannot be inhabited again for thousands of years without expensive remediation efforts. 

Pesticides may change the soil s element content. Some pesticides may increase plants micro- and macroelement content, such as nitrogen, phosphorus, calcium, potassium, magnesium, manganese, iron, copper, barium, aluminum, strontium and zinc, whereas others decrease these or other elements. Pesticides may cause ammoniac compounds to accumulate in the soil. Dimethoate and fluometuron increase nitrates in the soil, while DDT, carbaryl and HCH sharply decrease them. When prometrin was used, soil nitrate content decreased by 30-40% [3]. 

Ophel, I. L, and J.M. Judd. 1976. Strontium and calcium accumulation in fish as affected by food composition. Pages 221-225 in C.E. Cushing (ed.). Radioecology and Energy Resources. Proceedings of the Fourth National Symposium on Radioecology, 12-14 May 1975, Oregon State Univ., Corvallis, OR. Ecol. Soc. Amer., Spec. Publ. No. 1. 

Schultz, V. and W.M. Longhurst. 1963. Accumulation of strontium-90 in yearling Columbian black-tailed deer, 1950-1960. Pages 73-76 in V. Schultz, and A.W. Klement, Jr. (eds.). Radioecology. Reinhold, New York. 

The content of heavy metals in Steppe soils is tightly connected with their contents in geological rocks. In formation of soil exposure pathways in Desert ecosystems, water-soluble forms of these metals play the most important role. We can see an analogy between the increasing content of elements in soil dead organic matter as a function of decreasing water excess in Forest ecosystems and the increasing content of water-soluble species of chemical elements in the soils of Dry Steppe and Desert ecosystems as a function of enhanced aridity. The accumulation of water-soluble species occurs in the upper horizon for almost all elements, with exception of strontium. The main factor responsible for the accumulation of water-soluble forms is connected with evapotranspiration. 

Strontium, barium, manganese, copper, molybdenum, and nickel are elements of strong accumulation in plant species of African Savanna ecosystems, in spite of different content in soils and soil-forming rocks. The Cb values are >1. The other elements, like beryllium, zirconium, titanium and vanadium, are less taken up by plants and their Cb values are less than 0.5. These refer to various exposure pathways to both microbes and plants as links in biogeochemical food webs. 

Strontium-90, a radioactive strontium isotope with a half-hfe of 29 years, is a dangerous fallout source of radiation from atmospheric nuclear bombs. If a person is exposed to it, it will rapidly accumulate in bone tissue and interfere with the production of new red blood cells... 

Bone. Although bone is a relatively inert tissue, it can accumulate such substances as tetracyclines, lead, strontium, and the antitumor agent cisplatin. These substances may accumulate in bone by absorption onto the bone crystal surface and eventually be incorporated into the crystal lattice. Tetracycline deposition during odontogenesis may lead to a permanent yellow-brown discoloration of teeth, dysplasia, and poor bone development. Lead can substitute for calcium in the bone crystal lattice, resulting in bone brittleness. Bone may become a reservoir for the slow release of toxic substances, such as lead and cisplatin. 

Strontium, Sr (number 38), is especially dangerous to humans because it tends to accumulate in... 

Space Travel. See Astronautics A498 L Spanish Ammonals A292-L Stabilit. See Acardite I A7-R Stilbeneazostilbene. See Azostilbene A659-R Storage Batteries. See Accumulators A 12-L Strontium Acetylide or Strontium Carbide A82-R... 

Furthermore, it is also apparent that the region of the anode would become progressively more acidic, owing to an accumulation of acetic acid, as the electrolysis proceeds. In a similar manner, one would predict that the electrolysis of strontium nitrate solution would lead to the formation of oxygen gas and hydrogen gas at the anode and cathode, respectively. 

The anthropogenic radionuclides of most concern are those produced as fission products from nuclear weapons and nuclear reactors. The most devastating release from the latter source to date resulted from the April 26, 1986, explosion, partial meltdown of the reactor core, and breach of confinement structures by a power reactor at Chernobyl in the Ukraine. This disaster released 5 x 107 Ci of radionuclides from the site, which contaminated large areas of Soviet Ukraine and Byelorussia, as well as areas of Scandinavia, Italy, France, Poland, Turkey, and Greece. Radioactive fission products that are the same or similar to elements involved in life processes can be particularly hazardous. One of these is radioactive iodine, which tends to accumulate in the thyroid gland, which may develop cancer or otherwise be damaged as a result. Radioactive cesium exists as the Cs+ ion and is similar to sodium and potassium in its physiological behavior. Radioactive strontium forms the Sr2+ ion and substitutes for Ca2+, especially in bone. 

In solution culture experiments both strontium and caesium show hyperbolic absorption isotherms with respect to the external concentration of the element. Figure 7-15 (a) shows an example of a typical uptake isotherm for Sr while Shaw and Bell (1989) have demonstrated a similar isotherm for Cs. Baker (1981) has referred to such plant uptake responses as accumulator functions and has identified these as being typical of the absorption of elements over which plants can exert some degree of physiological control. Typically, the nutrient elements, including K and Ca, exhibit such isotherms and it can be postulated from the similarity in the uptake patterns of K and Cs on the one hand and Ca and Sr on the other that the radioions share, to some extent, the same uptake mechanisms as the nutrient ions. This has several important implications. Firstly, the direct competition for uptake sites between radioions and nutrient ions means that the external (soil) concentration of one is increased at the expense of the uptake of the other as the nutrient ions in question are vastly more abundant in soils than radioions it is K and Ca which will be effective in competitively excluding Cs and Sr, respectively. Secondly, the kinetics of this competition are concentration-dependent, so the assumption of first order kinetic movements of... 

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