Toxicity of the elements

Mercury contaminated foodstuffs and water supplies are a concern because of the extreme toxicity of the element and its compounds. Elemental mercury is used in the production of chlorine gas, and organomercury compounds formerly found use as pesticides and fungicides. Alkyl mercury compounds are of greatest concern since they do not degrade readily, and methyl mercury compounds concentrate in fish lipid tissue [9]. Pregnant women are at greatest risk since methyl mercury readily crosses the placenta, affecting the fetus [6]. 

Be is a spin = 2 nucleus with a relatively small quadrupolar moment (5.3 X 10 ° m ), good receptivity and 100% natural abundance. Despite its suitability for NMR studies, reeent solid-state Be NMR studies are relatively rare, probably due to the extreme toxicity of the element and its compounds, but possibly also because the narrow chemical shift range of Be detracts from its utility as a characterisation tool. Most of the solid state Be NMR studies reported to date have been of minerals which are comparatively non-toxie. Be chemical shifts are commonly reported relative to solid BeO. 

It is axiomatic that the toxicity of the ligand selected for the treatment and any side effects, such as co-liberating essential metals during therapy, ought, collectively, to add up to less than the residual toxicity of the element that has been deposited in the body. However, factors other than simple toxicity or unpleasant side effects need to be considered. For example, about 90% of the lead accumulated in the human body is sequestered in non-toxic form in bone. Incautious chelation therapy with an agent like EDTA, or administration of large amounts of... 

Castronovo FP and Wagner HN (1971) Factors tweeting the toxicity of the element indium. Br J Exp Pathol 52 543-559. 

Considering the ubiquitous presence of lead in the ecosystem and the toxicity of the element even at low levels, it is of paramount importance that the environmental lead pollution and human exposure are estimated with a view for risk assessment [5,9]. 

Disorders in farm animals involving both deficiency and toxicity of the element, selenium, are also associated with defined areas of land. It has been established that muscular dystrophy in lambs and calves can be prevented by selenium therapy and that it is a consequence of selenium deficiency in the herbage [100,101]. Such areas evidently occur naturally in several parts of the world [102-104],... 

Exposure to manganese dusts, fume, and compounds should not exceed the ceiling value of 5 mg/ms for even short periods because of the element s toxicity level. 

Under unusual circumstances, toxicity may arise from ingestion of excess amounts of minerals. This is uncommon except in the cases of fluorine, molybdenum, selenium, copper, iron, vanadium, and arsenic. Toxicosis may also result from exposure to industrial compounds containing various chemical forms of some of the minerals. Aspects of toxicity of essential elements have been pubhshed (161). 

The following discussion on health and safety aspects of titanium compounds is concerned only with the behavior of the titanium present in inorganic compounds and not with the effects of the compounds themselves. For example, titanium tetrachloride must be treated with care because of the effects of the hydrochloric acid and heat produced when it reacts with water, not because of the possible toxicity of titanium. Apart from very few exceptions, the inorganic compounds of titanium are generally regarded as having low toxicity. Because of the ubiquitous nature of the element and its compounds, average concentrations of titanium in blood have been determined at 130—160 Fg/L (182—184), with a typical value of 10 Fg/L in urine (185). 

Polonium is extremely toxic at all concentrations and is never beneficial. Severe radiation damage of vital organs follows ingestion of even the minutest concentrations and, for the most commonly used isotope, °Po, the maximum permissible body burden is 0.03/zCi, i.e. 1100 Bq (=1100s ), equivalent to 7 x 10 g of the element. Concentrations of airborne Po compounds must be kept below 4 x 10" " mgm . ... 

This example shows impressively that toxicity of a material is by far not only given by the kind of the element or the chemical composition it consists of, but that the size of the interacting species is at least of same importance. 

Also consider the use of NIST sediments 1646, 2704, and soils 2709-2711 in exploration geochemistry. These samples were certified largely in view of the demand for samples to support monitoring of toxic elements in environmental samples. However, many of the elements certified overlap either the list of primary ore elements or the list of pathfinder elements. Thus, these samples may legitimately be used in a very different application than the one that prompted certification. The sample matrix is ideal for the alternative application, and so is the suite of certified elements. 

Sanders CL. 1972. Deposition patterns and the toxicity of transuranium elements in lung. Health Phys 22 607-615. 

Beryllium is not the most aggressive of the elements (that is known to be fluorine), but it is considered the most toxic. 

The "smelly shoe" of the elements. The oxidation product S02 has an acrid, burning smell, the reduction product H2S stinks like rotten eggs and is very toxic. Sulfur is, nevertheless, a most useful element. It occurs in elemental form and has therefore been known for a long time is mentioned in the Old Testament. Its main application today is in the production of fertilizers. Considerable amounts of sulfur are used in tire production for vulcanization. Sulfur is also a component of gunpowder. Physiologically indispensable as thioacetic acid and especially the S-S bridges that fix proteins in their shapes (e.g. insulin, but also in perms). A 70-kg human being contains 140 g of sulfur. 

The extremely toxic trihydrides of the heavier atoms in group VA are not generally prepared by reaction of the elements. They are usually prepared by making a metal compound of the group VA element and... 

The environmental impact of tin is appreciable, as it is one of the three most enriched metals—only lead and tellurium precede—in the atmospheric particular matter, as compared with the abundance of the element in the earth crust (2.2 ppm). Tin releases to the environment can be methylated by aquatic organisms, yielding organometallic species of toxicity comparable to that of methylated mercury5. 

This review describes factors concerning the safety and environmental effects of organic germanium, tin and lead compounds. The factors involve the production and use of the elements, alkylation, degradation, toxicity, health effect assessment and so on. 

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