Mercury occupation with

Junghans RP A review of the toxicity of methyl mercury compounds with application to occupational exposures associated with laboratory uses. Environ Res 31 1-31, 1983... 

Data from the National Occupational Exposure Survey (NOES) conducted by NIOSH from 1983 to 1986, provides information on exposure to a variety of mercury compounds, with estimates of the total numbers of workers and the total number of female workers potentially exposed. As presented in Table 5-19, an estimated 50,468 women (33% of workers) were potentially exposed to mercury and various mercury compounds in occupational settings during 1983-1986 (RTECS 1998). More current estimates are not available for the number of women occupationally exposed to mercury in the United States or the percentage of women of reproductive age that may become pregnant or may breast-feed their infants while continuing to work in these occupational settings. 

Concentrations of mercury in blood, urine, and especially hair are generally recognized as the best indicators of methylmercury exposure. Concentrations of total mercury in the hair of persons with known occupational exposure to mercury and with a low consumption of fish are usually less than 5.0mg/kg FW. However, persons in Sweden and Finland with high consumption of mercury-contaminated fish and without symptoms of mercury intoxication often contain hair mercury levels > 30.0 mg/kg, and in one case 180.0 mg/kg. 

FAS is normally characterized by growth retardation, anomalies of the head and face, and psychomotor dysfunctions. Excessive consumption of ethyl alcohol may lead to malformations of the heart, extremities, and kidneys. Since consumption of ethyl alcohol is socially acceptable and prevalent even in pregnant women, the risks associated with the use of ethyl alcohol are remarkable. However, it should be kept in mind that there are several chemical compounds in tlie occupational environment that may also cause malformations even at low doses. The oc-cupationally-important known human teratogens include methyl mercury, ethyl alcohol, PCB compounds, tobacco smoke, lead, TCDD, 2,4,5- F, carbon monoxide, nitrogen dioxide, gasoline, and fluoride. 

In several epidemiological studies, no increased risk for congenital abnormalities, stillbirths, or spontaneous abortions was observed with occupational exposure to mercury. Exposure of pregnant rats on gestational days 10-15 at 0.5mg/m resulted in an increased incidence of resorptions gross cranial defects occurred at this dose when it was administered throughout the entire gestational period. "... 

Methyl mercury concentrations in hair can be used as an indicator of mercury concentration in blood, with a ratio of blood to hair of 1 250. Under occupational conditions, the possibility of external contamination of hair should be kept in mind. 

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. 

All bulk elemental analysis methods, such as NAA and FAAS, suffer from the serious disadvantage of lack of specificity in that the elements detected are not unique to FDR but also occur from occupational and environmental sources. Many surveys were carried out to determine background levels of lead, antimony, and barium on the hands of people not involved with firearms. Some surveys also included copper and mercury. Both general and occupational data were gathered and threshold levels established for each of the elements. The threshold level may be defined as the level above which the results may be significant and correlate to the discharge of a firearm. The best that could be stated was that the levels detected were consistent with the discharge of a firearm but could not be taken as conclusive proof of the presence of FDR. 

Organomercurials have been a common cause of allergic contact dermatitis or rash (22) and even exfoliative dermatitis has been described (23). Some reagents for intra-cutaneous testing (tuberculin, etc.) may contain thiomersal, which can cause sensitization and thus elicit false-positive delayed-type skin reactions. Mercury compounds inhibit most lymphocyte functions (SEDA-21, 240). An early indicator of an immunological response to mercury exposure, for example in occupational medicine, appears to be a change in the lymphocyte count with a differential increase in T helper cells and a rise in the T helper/T suppressor ratio (24). 

The unique physical properties of metallic mercury led to its widespread industrial use during the 19th century. Because of this, epidemics of occupational poisonings were documented in the mirror and felt hat industries. Symptoms and signs of severe poisoning included pneumonitis, tremor, inflammation of the gums with excessive salivation, and psychiatric symptoms such as excitability, insomnia, irritation, and shyness. 

Studies from New Zealand and the Faroe Island indicate that adverse effects in children can be correlated with maternal hair levels as low as 10-20 pg/g [44]. Mercury analyses conducted on a single human hair can be used to monitor daily variations in methyl mercury exposure among fish eaters [45,46], and have been utilized to track maternal fish consumption and risk of preterm delivery [47]. Other investigators [48] have utilized measurements of total mercury in hair, toenails and urine to assess exposures in a group of non-occupationally exposed women in relation to renal tubular effects. 

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