Metal poisoning, chronic

Although trace amounts of manganese are essential for animals, in large quantities the metal can cause acute and chronic poisoning. Chronic inhalation of metal dust or fumes can cause manganism, a nonfatal disease affecting the central nervous system. The symptoms are mental disorder and disturbance in speech. 

If heavy metal poisoning is suspected, the kidneys often show histological damage due to the metal, and also the metals causing the damage tend to concentrate in the kidneys. If the metal poisoning is suspected of being a chronic condition, then s[Pg.113]

Several toxic metals, including arsenic, iron, lead, and mercury, are discussed in Chapters 30 and 35. Their measurement in urine, blood, and hair (in some cases) is valuable to help diagnose acute or chronic metal poisoning. Specific therapy for these toxins is listed in Table 34-1. Because the assessment of acute iron overdose requires emergency laboratory support, it is discussed in this chapter. 

Mercury is a very useful chemical, and if handled properly, can be used routinely without fear. There is no need to shut down a laboratory because of a mercury spill. Clean it up immediately and continue. However, if spillage is not cleaned up, the vapors can cause chronic metal poisoning after prolonged exposure (Table 6-2). An extreme example is the old-time Hatter s disease. This occurred when hat makers treated beaver fur with HgfNOj), to permit the fiir to kink into felt. After continued exposure, the hatters often got the shakes. Anyone who shook was mad as a hatter. Mereurous compounds are much less soluble than mercuric compounds. In fact, a spoonful of calomel (Hg2Cl2) often was given... 

Mercury forms strong covalent bonds with sulfur. If the sulfur happens to be in an amino acid (cystine, cysteine, methionine), in a protein, or an enzyme then poisoning can occur. One result of this interaction is that Hg accumulates in toe and finger nails as well as in hair. Almost everyone has some Hg in their nails and hair, but an excessive amount can indicate chronic heavy metal poisoning. A survey of Hg in the hair of 17 general population people indicated 6.0 2.9 ppm. Dentists had 9.8 4.7 ppm. 

The toxic effects of the mineral elements are extremely element- and species-specific (Hapke 1991). The symptoms of acute poisoning (Geldmacher von Mallinckrodt 1991a) and chronic toxicity of inorganic elements can be completely different (Ewers and Schlipkoter 1991). The most common symptoms of acute metal poisoning include the following ... 

For most workplace exposures, symptom onset is more often insidious, following a subaoute or chronic pattern, as in heavy metal poisoning. 

Among the most important causes of chronic renal failure are chronic glomerulonephritis, chronic pyelonephritis and hypertension. Various tubular disorders, such as heavy metal poisoning, Wilson s disease and tubular damage caused by hyper-calcaemia or hyperuricaemia, may also lead to generalized chronic renal failure. 

Tanaka, Y. and Stara, J.F. (1979) Algal polysaccharides their potential use to prevent chronic metal poisoning, in Marine Algae in Pharmaceutical Science (eds H.A. Hoppe, T. Levring, and Y. Tanaka), Walter de Gruyter, Berlin, New York, pp. 525-543. 

Workers who produce or use lead should be aware of possible ha2ards. Symptoms of chronic lead poisoning include fatigue, headache, constipation, uneasy stomach, irritabiHty, poor appetite, metallic taste, weight loss, and loss of sleep. Most of these same symptoms also occur in many common illnesses, such as the flu, thus a physician must rely on tests, such as blood lead analysis, to determine chronic lead poisoning. 

Biagini G, Caudarelia R, Vangelista A. 1977. Renal morphological and functional modification in chronic lead poisoning. In Brown SS, ed. Clinical chemistry and chemical toxicology of metals. Elsevier/North-Holland Biomedical Press, 123-126. 

Bulmer, F.M.R., H.E.Rothwell, S.S.Polack, and D.W.Stewart, D.W. 1940. Chronic arsine poisoning among workers in the cyanide extraction of gold from metallic dross. Arch. Ind. Hyg. Occup. Med. 1 419. 

This area was the most profusely studied in the AQUATERRA project in terms of biological effects in fish populations. Barbel and bleak were the sentinel species selected in this area and an array of histological and biochemical tests were used to monitor the impact due to three major sources of pollution mercury and OCs at Monzon (with a comparison in one of the papers with Flix) and PBDEs in Barbastro [1—4, 37]. Mercury pollution was directly correlated to an increase of MTprotein in the liver of barbel captured downstream Monzon when compared to samples captured upstream (Fig. 3a). However, mRNA quantitative analyses failed to show any differences between downstream and upstream Monzon, neither correlated with MT protein levels. Further studies showed that MT mRNA in liver is a rather weak marker for chronic metal pollution in liver (see below) [4], The presence of degenerative hepatocytes in barbels and bleaks was also linked to mercury poisoning although it can also reflect the impact by other pollutants, like OCs or PBDEs (Fig. 3e). 

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