Metal toxicity beryllium

Hazardous waste burning incinerators, cement kilns, and LWAKs do not follow a tiered approach to regulate the release of toxic metals into the atmosphere. The MACT rule finalized numerical emission standards for three categories of metals mercury, low-volatile metals (arsenic, beryllium, and chromium), and semivolatile metals (lead and cadmium). Units must meet emission standards for the amount of metals emitted. For example, a new cement kiln must meet an emission limit of 120pg/m3 of mercury, 54pg/m3 of low-volatile metals, and 180 pg/m3 of semivolatile metals. 

The environmental scientist has at his disposal a variety of sensitive, multi-elemental analytical methods that can lead to a massive amount of data on airborne metals. Optimum use of these tools for environmental monitoring calls for focusing resources only on those metals that are environmentally important. Considerations of toxicity along with their ability to interact in the air, leading to the formation of secondary pollutants, and their presence in air have led to the identification of 17 environmentally important metals nickel, beryllium, cadmium, tin, antimony, lead, vanadium, mercury, selenium, arsenic, copper, iron, magnesium, manganese, titanium, chromium, and zinc. In addition to the airborne concentration, the particle size of environmentally important metals is perhaps the major consideration in assessing their importance. 

Beryllium, on the other hand, is toxic. Beryllium disease, originally called berylliosis, was first noted in the 1930s in German and Russian plants set up to extract the metal from beryllium ores such as beryl. As the use of this metal has increased, so also has the incidence of this disease. It occurs in both acute and chronic forms. 

Beryllium and its salts are toxic and should be handled with the greatest of care. Beryllium and its compounds should not be tasted to verify the sweetish nature of beryllium (as did early experimenters). The metal, its alloys, and its salts can be handled if certain work codes are observed, but no attempt should be made to work with beryllium before becoming familiar with proper safeguards. 

No fewer than 14 pure metals have densities se4.5 Mg (see Table 10.1). Of these, titanium, aluminium and magnesium are in common use as structural materials. Beryllium is difficult to work and is toxic, but it is used in moderate quantities for heat shields and structural members in rockets. Lithium is used as an alloying element in aluminium to lower its density and save weight on airframes. Yttrium has an excellent set of properties and, although scarce, may eventually find applications in the nuclear-powered aircraft project. But the majority are unsuitable for structural use because they are chemically reactive or have low melting points." ... 

The salts of the heavy metals beryllium, cadmium, chromium, copper, lead, mercury, nickel and zinc are all of high eco-toxicity. For example, the toxicity of some heavy metals to rainbow trout is demonstrated in Table 16.13 coarse fish are somewhat more resistant. 

Two other factors are noteworthy the deleterious effects on chemical and mechanical properties of small amounts of impurities residual from extraction of the metal, and its toxicity. The first of these factors is obviated by vacuum melting the raw metal (for purification) as an essential prerequisite to further processing. The toxicity of beryllium is essentially a pulmonary problem and great care must be taken in handling the finely divided metal or its compounds. In practice, this type of activity is usually carried out under well-ventilated conditions. Certain tolerance levels for atmospheric beryllium are now internationally accepted and merit careful study before work on beryllium is embarked upon. 

The early promise of wide applications for beryllium has not materialised, despite improvements in purity and more efficient means of consolidation such as isostatic hot pressing, because of the metal s toxicity, brittleness and cost. It is now chiefly of interest in the specialised fields of aerospace and nuclear applications. BrushWellman is currently the sole commercial primary producer of beryllium metal in the West. 

Beryllium i s a strong and light metal with useful nuclear character-istics (its atomic number is 4). It oxidizes readily and the oxide is toxic. Its properties are li sted in Tabl e 6.2. It i s produced by C VD on an experimental basis. 

Metals are divided into light (also called alkali-earth metals) and heavy. All toxic metals are heavy metals except for beryllium and barium. Additionally, other categories of elements that are or may be significant chemically as dissolved species in deep-well-injection zones include the following ... 

The combination of toxic hazard and high price (itself in part due to the extra measures needed in production processes to ensure the workers safety) has been an effective brake on commercial development of beryllium chemistry. Where possible substitute, albeit less effective, materials are often used titanium as an alternate lightweight metal or carbon fiber composites, phosphor-bronzes in place of beryllium alloys, aluminum nitride in place of BeO (1). 

Beryllium. Be metal is relatively unreactive at room temperature it does not react with water and steam even at red heat and it does not oxidize in air below 600°C. Powdered beryllium burns in air brilliantly on ignition forming BeO and Be3N2. It reacts with the halogens and dissolves easily in dilute aqueous acid solutions. It is passivated by cold concentrate HN03. The Be compounds, especially as dusts or smokes, are extremely toxic (possibly due to the ability of Be11 to displace Mg11 from Mg-activated enzymes). 

Metals are extremely important not only for chemical reactions but also for the health and welfare of plants and animals. Some examples of metals required for good nutrition, even in trace amounts, are iron, copper, cobalt, potassium, sodium, and zinc. Other metals—for example, mercury, lead, cadmium, barium, beryllium, radium, and uranium—are very toxic. Some metals at the atomic and ionic levels are crucial for the oxidation process that metabolizes carbohydrates for all living cells. 

The elemental metallic form of beryllium is highly toxic, as are most of its compounds. When inhaled, the fumes, dust, or particles of berylhum are highly carcinogenic. Some beryllium compounds are toxic when they penetrate cuts in the skin (e.g., when an old fluorescent tube breaks). Beryllium oxide when inhaled can result in a fatal disease known as berylliosis (similar to, but more toxic than, sihcosis). 

Beryllium (Be) is a gray-colored brittle metal. Be bums in air to form BeO or B03N2, releasing a high heat of combustion. However, Be and its compounds are known as highly toxic materials. 

A number of objections have been raised to the use of the term. In the first place, the list of so-called heavy metals usually includes some elements that are not even metals, such as the semimetals arsenic and antimony. Also, some of the "heavy metals" are not really very "heavy" by almost any standard. Beryllium, for example, has an atomic mass of about 9, and aluminum, an atomic mass of about 27. Yet both are often classified as "heavy metals." For these reasons, some authorities now prefer the term toxic metals to the more traditional term heavy metals. Either term can refer to elements in both their free and combined states. The table on pages 120-121 provides an overview of the sources and health effects of some heavy metals,... 

Metals more electronegative than magnesium, like beryllium, zinc, cadmium and mercury, form useful reagents for specific purposes, but the metals themselves are not sufficiently active to form organic derivatives under normal laboratory conditions and are unwanted in the environment since they are toxic. Aluminum compounds are useful for industrial purposes, but their use in the laboratory is insignificant in comparison with Grignard reagents. 

Occupational and environmental poisoning with metals, metalloids, and metal compounds is a major health problem. Exposure in the workplace is found in many industries, and exposure in the home and elsewhere in the nonoccupational environment is widespread. The classic metal poisons (arsenic, lead, and mercury) continue to be widely used. (Treatment of their toxicities is discussed in Chapter 57.) Occupational exposure and poisoning due to beryllium, cadmium, manganese, and uranium are relatively new occupational problems, which present new and previously unaddressed problems. 

Because of its toxicity, the number of well-characterized beryllium compounds of all types is much lower than that of the other alkaline earth metals. The largest number of the pubhshed berylhum structures involve oxygen donor ligands, " and beryllium amides have been reviewed, at least in part, under the aegis of wider-ranging surveys - of group 2... 

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