Toxicity of strontium

Cole W, Hamed BK, Hafkesbring R. 1941. The toxicity of strontium and calcium. J Pharmacol Exp Ther 71 1-5. 

Kroes R, den Tonkelaar EM, Minderhoud A, et al. 1977. Short-term toxicity of strontium chloride in rats. Toxicology 7(1) 11-21. 

Looser D, Connoisseur AL. 1930. A study of the toxicity of strontium and comparison with other cations employed in therapeutics. J Lab Clin Med 15 35-41. 

Raabe OG, Culbertson MR, White RG, et al. 1994. Comparative toxicity of strontium-90 and radium-226 in beagle dogs. Department of Energy. Davis, CA University of California. DOEDE-FG03-89ER60914/92. NTIS/DE94006408. 

Thomasset M. 1982. Strontium metabolism and toxicity of strontium. In Galle P, Masse R, ed. Radionuclide Metabolism and Toxicity Proceedings of the Symposium organized in 1982 by the Societe Francaise de Biophysique et de Medecine Nucleaire and IRU-Environnement del Universite Paris-Val de Marne. Paris New York Masson, 98-121. 

Although present information on the toxicity of strontium is scarce, strontium seems to be a relatively low toxic element to man and animals investigated by experimental studies (Clausen 1983, Cochran et al. 1950,... 

Research on the toxicity of strontium compounds has mainly been focused on the effects of radiation of radioactive strontium. Limited information is available on the toxicity of stable strontium. In general, it can be stated that strontium has a very low order of toxicity [5,6]. However, it needs to be stressed that toxic levels established in feeding studies strongly depend on the composition of the diet, especially with regard to the contents of calcium and phosphate. 

Coatings, Paints, and Pigments. Various slightly soluble molybdates, such as those of zinc, calcium, and strontium, provide long-term corrosion control as undercoatings on ferrous metals (90—92). The mechanism of action presumably involves the slow release of molybdate ion, which forms an insoluble ferric molybdate protective layer. This layer is insoluble in neutral or basic solution. A primary impetus for the use of molybdenum, generally in place of chromium, is the lower toxicity of the molybdenum compound. 

Health and Safety Factors. The strontium ion has a low order of toxicity, and strontium compounds are remarkably free of toxic hazards. Chemically, strontium is similar to calcium, and strontium salts, like calcium salts, are not easily absorbed by the intestinal tract. Strontium carbonate has no commonly recognized hazardous properties. Strontium nitrate is regulated as an oxidizer that promotes rapid burning of combustible materials, and it should not be stored in areas of potential fire hazards. 

Cochran KW et al Acute toxicity of zirconium, columbium, strontium, lanthanum, cesium, tantalum and yttrium. Arch Ind Hyg Occup Med 1 637-650, 1950... 

There are a few elements in these two groups that sometimes cause health problems because they are very similar to nearby elements. For instance, a toxic type of strontium can increase the risk of bone cancer and leukemia. Strontium, just one space below calcium in the table, is so similar to calcium that the body is sometimes fooled into absorbing it like calcium in bones and teeth. The similarities between elements can also be useful, as in the case of potassium chloride. People with high blood pressure and certain heart or kidney diseases need less sodium in their diets to stay healthy. Instead of sprinkling regular table salt or sodium chloride on their meals, they may use potassium chloride for a very similar salty taste. 

Shubochkin LN, Pokhodzie YI. 1980. Toxic properties of strontium chromate. Gig Sanit 45 76-77. 

One radioactive isotope of strontium, strontium-90, is of special interest. It is a toxic substance, which, at one time, was the cause of great concern because of its connection to atomic bomb testing. 

It should be noted that radioactive contaminants are not to be compared with their stable chemical counterparts. For example, because of the unchangeable character of the nuclear disintegration phenomenon, the natural purification processes which restore chemical and biological balances in the environments of living" things, would have no effect on the radio-toxic properties of the radioactive elements. The time required for accumulations of strontium-90 to decay to background levels, would... 

Health Region of Sivas, Turkey. Other factors in this study included a probable deficiency in vitamin D, because of the lack of sunshine, and a deficiency in calcium in the diet after weaning. The potential skeletal toxicity of excess strontium in humans is supported by several reports indicating that hemodialysis patients have impaired handling of strontium and that strontium in dialysis water is a significant contributor to dialysis-associated osteomalacia. 

Stable Strontium. Data on the toxicity of inhaled stable strontium are limited to a case report of a woman exposed to an undetermined concentration of strontium from an ignited flare (Federman and Sachter 1997). 

The primary purpose of this chapter is to provide public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective on the toxicology of strontium, in both its stable (nonradioactive) and radioactive forms. This chapter contains descriptions and evaluations of toxicological studies and epidemiological investigations and provides conclusions, where possible, on the relevance of toxicity and toxicokinetic data to public health. 

Strontium is fairly reactive and therefore is rarely found in its pure form in the earth s crust. Examples of common strontium compounds include strontium carbonate, strontium chloride, strontium hydroxide, strontium nitrate, strontium oxide, and strontium titanate. The most toxic strontium compound is strontium chromate, which is used in the production of pigments and can cause cancer by the inhalation route. Strontium chromate is not included in the Levels of Significant Exposure (LSE) tables for strontium since the carcinogenic effects of the compound are a function of the concentration of hexavalent chromium, and strontium only contributes to solubility. The Toxicological Profile for Chromium (ATSDR 2000) should be consulted for additional information on the health effects of strontium chromate. 

This section includes injection and in vitro studies that provide evidence for the biological basis of toxicity of stable and radioactive strontium in humans and animals. Since these studies are not directly relevant to general population exposure conditions, no LSE tables have been created for this section. 

Stable Strontium. The toxicity of excess stable strontium is related to its interference in biological processes that normally involve calcium, most notably, skeletal development. 

Several agents reduce the absorption or retention of strontium, reducing its toxic effects (see Section 3.11). 

A susceptible population will exhibit a different or enhanced response to strontium than will most persons exposed to the same level of strontium in the environment. Reasons may include genetic makeup, age, health and nutritional status, and exposure to other toxic substances (e.g., cigarette smoke). These parameters result in reduced detoxification or excretion of strontium, or compromised function of organs affected by strontium. Populations that are at greater risk due to their unusually high exposure to strontium are discussed in Section 6.7, Populations With Potentially High Exposures. 

Stable Strontium. There is no evidence regarding the effect of stable strontium on reproduction, but levels of exposure possible by inhalation or dermal routes are not likely to be harmful. Stable strontium was found to have beneficial effects when it was used in solutions designed for testing the functional capacity of human spermatozoa in vitro (Mortimer 1986 Mortimer et al. 1986). The possible consequences of excess strontium ingestion on reproduction need to be explored. Such experiments should compare the relative toxicity of stable strontium compounds that have different properties and may have different rates of absorption, e.g., strontium chloride, strontium carbonate and strontium phosphate. 

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