Electromyographic Changes in Automechanics With Increased Heavy Metal Levels

Abstract

Twenty automechanics possessing increased whole blood values of one or more of the following heavy metals; chromium, copper, lead, manganese and nickel, were studied for peripheral nerve affection by means of electromyography (both sensoric and motoric nerve potentials were recorded). The heavy metal contents were related to the findings of denervation, distal motor latency, distal sensory latency, motoric and sensoric conduction velocities. Apart from two workers, in whom only lead was assayed, the remaining group of 18 were assayed for all heavy metals under study. Six workers showed increased distal motor and/or sensory latency and seven decreased nerve conduction velocity (four motoric and three sensoric affections). Of the workers with nerve affection, three showed increased levels of lead (nickel and chromium also raised). Four workers showed increased lead, nickel and chromium and one of lead, chromium and manganese. All in all, 10 out of 20 workers (50 percent) with elevated lead levels showed definite signs of peripheral neuropathy and seven out of 14 with raised nickel values showed these signs but they could all be accounted for by the increased lead levels. All except seven workers with raised lead levels in the whole group showed values above the critical limit of 80.0 mug/100 ml in whole blood. The data argue for the highly toxic effect of lead and other heavy metals on the peripheral nervous system and stress the diverse toxic exposure which automechanics undergo during their work. The possibility of there being a synergistic action between heavy metals and components of mineral oil and petroleum is discussed.

Lead Health Effects in Drinking Water

“…Similar studies (Amvig et al, 1980;Grandjean et al , 1978;Haenninen et al , 1978;Mantere et al , 1982;Valciukas et al , 1978) have found disturbances in visual motor performance, IQ test performance, hand dexterity, mood, nervousness and coping in lead workers with blood lead levels of 50 to 80 J,Lg/dL. Similarly, Melgaard et al (1976) observed a clear association between lead exposure and peripheral nerve dysfunction in automobile mechanics exposed to tetra-ethyl lead and other compounds in lubricating and high-pressure oils. (1976) found no differences between control and lead-exposed workers as judged by numerous psychometric and other performance tests.…”

Heavy metal pollution among autoworkers. II. Cadmium, chromium, copper, manganese, and nickel.

“…Manganese and nickel can, like lead, give rise to peripheral neuropathy and brain damage (Tolonen, 1972). Our recent electrophysiological investigation (Melgaard et al, 1976b) showed peripheral nerve abnormalities in autoworkers with high heavy metal levels. The high levels of nickel, chromium and manganese among the autoworkers underlines the need for scrupulous hygiene in autoworkshops.…”

Heavy metal pollution among autoworkers. I. Lead.

“…The heavy metal content and ALAD activity of whole blood from the control group has been previously defined (Melgaard et al, 1976a). The lead content and ALAD activity in the blood of autoworkers is shown in Table 2.…”

“…Assay of 8-aminolevulinic acid dehydratase (ALAD) activity and lead content in whole blood and determination of &-aminolevulinic acid (ALA) in urine have been described previously (Melgaard et al, 1976a). Lead in dust and oil samples (about 30 mg) was extracted by heating them twice to 100°C for two hours with 2 ml concentrated hydrochloric acid-nitric acid (1 :1) mixture.…”

“…Complaints related to the central nervous system may be due to heavy lead load (Carson et al, 1974), possibly as a result of working with organic lead derivatives (Frost and Myschetzky, 1969);Lansdown et al, 1974;Konat and Clausen, 1974;Melgaard et al, 1976a and b). However, dizziness and headaches may also be due to organic solvents such as hexane.…”