Occupational exposure manganese

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. 

The best way to monitor excessive exposure to manganese includes serum manganese concentration measurement in combination with brain MRI scanning and perhaps a battery of neurofunctional tests (7). Studies have concentrated on manganese in patients on parenteral nutrition (8) and occupational exposure (9). 

Following occupational exposure, neurobehavioral effects resembling parkinsonism have been observed in a series of manganese workers at exposures well below current occupational standards (13) higher levels of exposure can cause dystonic rigidity and proximal tremor. The late effects of currently asymptomatic exposure are uncertain however, in Chilean workers with past exposure in manganese mines, hand tremor was detectable (14). 

Most human exposure to maneb is via occupational exposure. Cases of diffuse erythema and eczematoid dermatitis have been observed among agricultural workers. Studies on maneb production workers showed elevated levels of ETU in the urine and high blood levels of manganese. Very slight alterations to thyroid function were observed. 

Fly ash from municipal waste and industrial waste incinerators contains polychlorinated dibenzo-p-dioxins (PCDDs), including tetrachlorodibenzo-/j-dioxin (TCDD) and polychlorinated dibenzofurans (PCDFs), which are lipophiles, and heavy metals, including chromium, copper, manganese, vanadium, and lead, which are hydrophilesJ29-31 These chemicals have multiple toxicities and are known to impact the human liver, immune system, respiratory system, thyroid, male reproductive function, and CNS J32 34l Several are human carcinogensJ32 35 Enhanced toxic effects are observed in the mixtures of some of theseJ21,22 36 The mixtures of toxicants present in fly ash are complex and the mechanisms for their action on the human body are largely unknown. It is known that occupational exposure to fly... 

Hua M-S, Huang C-C Chronic occupational exposure to manganese and neurobehav-ioral function. J Clin Exp Neuropsychol 13 495-507, 1991 Huang C-C, Chu N-S, Lu C-S, et al Chronic manganese intoxication. Arch Neurol 46 1104-1106, 1989... 

Saric M, Markicevic A, Hrustic O Occupational exposure to manganese. British Journal of Industrial Medicine 34 114-118,1977 Schuler P, Oyanguren H, Maturana V, et al Manganese poisoning environmental and medical study at a Chilean mine. Industrial Medicine and Surgery 26 167-173, 1957... 

An increased prevalence of infectious lung disease (especially pneumonia) has also been noted in some studies of workers with chronic occupational exposure to manganese dust (Lloyd Davies 1946) and in residents near a ferromanganese factory (WHO 1987). It seems likely that this increased susceptibility to... 

Gorell et al. (1999) noted a high Odds Ratio (OR) of 10.51 for the development of Parkinson s disease in individuals older than 50 who were occupationally exposed to manganese for greater than 20 years, but not for those exposed for fewer than 20 years. However, the numbers of individuals with a >20 year exposure was rather small (4), and occupational exposures to other metals (copper, and lead-iron, lead-copper, and iron-copper combinations) for greater than 20 years were also associated with increased risk for the disease. 

As discussed earlier (see Section 2.2.1.4), impotence and loss of libido are common symptoms in male workers afflicted with clinically identifiable signs of manganism attributed to occupational exposure to manganese for 1-21 years (Emara et al. 1971 Mena et al. 1967 Rodier 1955 Schuler et al. 1957). Obviously, these symptoms could lead to reduced reproductive success in men. Impaired fertility (measured as a decreased number of children/married couple) has been observed in male workers exposed for... 

These results in human studies reveal conflicting evidence for whether occupational exposure to manganese causes adverse reproductive effects. Effects reported may occur as a secondary result of neurotoxicity but do not provide information on any direct effect manganese may have on the reproductive organs. No information was found regarding reproductive effects in women. 

There are two studies showing neurological effects following occupational exposures to manganese-containing pesticides (Ferraz et al. 1988 Meco et al. 1984). The Ferraz et al. (1988) study is negahvely impacted by the likely exposure of the subjects to a wide variety of peshcides and the lack of a well-matched control group. Addihonal studies in occupationally-exposed persons with restricted exposure to only maneb and mancozeb are needed. 

Occupational exposure to manganese resulting from the combustion of MMT in Montreal, Canada has been studied. Sierra et al. (1995) conducted a study of Montreal automotive workers (garage mechanics) and nonautomotive workers (control group). Exposure to manganese was measured for 5 consecutive working... 

Maneb or mancozeb. Headley (1996) used an inductively coupled plasma-atomic emission spectrometry (ICP-AES) method for occupational exposure estimations that measures mancozeb by determining the elemental manganese portion of the pesticide in a sample. The method was successful in analyzing urine (0.02 mg/L), wash water (0.02 mg/L), tank mixes (0.02 mg/L), cellulose acetate filters (0.5 pg), and fabric from patches and clothing (0.5 pg), with detection limits in parentheses. However, ICP-AES methods cannot differentiate among various forms of manganese, so it is important that background... 

Gorell JM, Johnson CC, Rybicki BA, et al. 1999. Occupational exposure to manganese, copper, lead, iron, mercury, and zinc and the risk of Parkinson s Disease. Neurotoxicology 20 239-248. 

Hua MS, Huang CC. 1991. Chronic occupational exposure to manganese and neurobehavioral function. J Clin Exp Neuropsychol 13 495-507. 

Eoranger S and Zayed J. 1995. Environmental and occupational exposure to manganese A multimedia assessment. Int Arch Occup Environ Health 67 101-10. 

Due to preventive measures, manganese has become a minor factor in occupational exposure in Germany during the past few decades. Since 1994, only two cases of recognized occupational diseases related to manganese have been reported (Seifert et al. 

Seieert M, Van Gelder R, Hahn J-U and Schafer U (2001) Occupational exposure to manganese in Germany Aspects of toxicity, measurements and prevention. In Ermidou-Pollet S, Pollet S, eds. 

Nervous System Occupational exposure to manganese is common through various sources including welding fumes. A worksite-based study involving 811 welders demonstrated a high prevalence of Parkinsonism compared to nonwelding-exposed workers [164 J. 

Mehra R, Bhalla S. 1998. Determination of chromium, manganese, iron and nickel content of hair for evaluating exposure to metals in occupational environment. Oriental Journal of Chemistry 14(1) 117-120. 

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