Summary
A cross-sectional study was performed in order to investigate the influence of chronic lead-exposure on the peripheral nervous system. We examined 148 male workers of a storage battery manufacturing plant, who had been exposed to lead metal and inorganic lead compounds for 1 to 28 years (mean 11 years). Fifteen workers with non-occupational risks of peripheral neuropathy (former diseases, alcohol abuse, medication) were excluded from the study. The investigation program comprised: case history, physical examination, analyses of blood- and urine-samples and determination of maximal motor, mixed and sensory conduction velocity (NCV) of the ulnar and median nerve of the right forearm. Objectively no worker showed any signs of health effects related to lead exposure. The “Biological Monitoring” included the determination of (1) Blood-lead level (Pb-B), (2) Free erythrocyte porphyrins (FEP), (3) δ-Aminolevulinic acid dehydratase (ALA-D) and (4) δ-Aminolevulinic acid in urine (ALA-U). Further “time-weighted-average (TWA)”-values of Pb-B were calculated on the basis of several determinations over the period 1975–1981. The following “actual” (“TWA”) median values resulted: Pb-B 53 μg/dl (54 μg/dl), ALA-U 5.6 mg/l (8.4 mg/l), FEP 2.0 mg/l (2.0 mg/l). The “Biologischer Arbeitsstoff Toleranz Wert (BAT)” of 70 μg//dl for Pb-B was exceeded in 15 workers (11%), and of 15 mg/l for ALA-U in 30 cases (23%). In comparison with age-matched controls, the lead workers showed a mild slowing of NCV with mean values between 0.8 and 2.0 m/s. Multiple stepwise regression analyses revealed statistically significant correlations between the four NCV and age as well as Pb-B. There were better correlations by using “TWA” than “actual” data of Pb-B. Consideration of the results of the regression analyses, together with an evaluation of the individual neurophysiological status as a function of internal lead exposure, a “dose-effect-relationship” was found only in the case of Pb-B exceeding 70 μg/dl. From our study it is concluded that chronic lead exposure resulting in blood-lead levels of below 70 μg/dl is no occupational risk causing a functionally significant slowing of nerve conduction velocities.
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References
Alessio L, Bertazzi PA, Toffoletto F, Foa V (1976a) Free erythrocyte protoporphyrin as an indicator of the biological effect of lead in adult males. I. Relationship between free erythrocte protoporphyrin and indicators of internal dose of lead. Int Arch Occup Environ Health 37:73–88
Alessio L, Bertazzi PA, Toffoletto F, Foa V (1976b) II. Comparison between free erythrocyte protoporphyrin and other indicators of effect. Int Arch Occup Environ Health 37:89–105
Alessio L, Castoldi MR, Odone P, Franchini I (1981) Behaviour of indicators of exposure and effect after cessation of occupational exposure to lead. Br J Ind Med 38:262–267
Araki S, Honma T (1976) Relationships between lead absorption and peripheral nerve conduction velocities in lead workers. Scand J Work Environ Health 4:225–231
Araki S, Honma T, Yanagihara S, Ushio K (1980) Recovery of slowed nerve conduction velocity in lead-exposed workers. Int Arch Occup Environ Health 46:151–157
Ashby JAS (1980) A neurological and biochemical study of early lead poisoning. Br J Ind Med 37:133–140
Baloh RW, Spivey GH, Brown CP, Morgan D, Campion DS, Browdy BL, Valentine JL, Gonick HC, Massey FJ Jr, Culver BD (1979) Subclinical effects of chronic increased lead absorption — a prospective study. J Occup Med 21:490–496
Behling K, Pott R (1982) Nervenleitgeschwindigkeit und Fingertremor bei beruflicher Bleiexposition. Bericht über die 22. Jahrestagung der Deutschen Gesellschaft für Arbeitsmedizin e. V. Gentner Verlag, Stuttgart, S 619–623
Behse F, Buchthal F (1971) Motor and sensory conduction velocity in the nerves of the leg in man. J Neurol Neurosurg Psychiat 34:404–414
Berlin A, Schaller KH (1974) European standardized method for the determination of aminolevulinic acid dehydratase activity in blood. Z Klin Chem Klin Biochem 12:389–390
Bordo B, Massetto N, Musicco M, Filippini G, Boeri R (1982) Electrophysiologic changes in workers with “low” blood lead levels. Am J Ind Med 3:23–32
Brockmann W, Laurig W, Nottbohm L (1981) Vereinfachung des “Biological Monitoring” durch ein statistisches Entscheidungsmodell. Arbeitsmed, Sozialmed, Präventivmed 16:196–200
Buchthal F, Behse F (1979) Electrophysiology and nerve biopsy in men exposed to lead. Br J Ind Med 36:135–147
Catton MJ, Harrison MJG, Fullerton PM, Kazantzis G (1970) Subclinical neuropathy in lead workers. Br Med J 2:80–82
Davis RS, Andelman SL (1967) Urinary delta-aminolevulinic acid (ALA) levels in lead poisoning. A modified method for the rapid determination of urinary delta-aminolevulinic acid using disposible ion-exchange chromatography colums. Arch Environ Health 15:53–59
Dorfman LJ, Bosley TM (1979) Age-related changes in peripheral and central nerve conduction in man. Neurology 29:38–44
Englert N (1980) Periphere motorische Nervenleitgeschwindigkeit bei Probanden mit beruflicher Blei-Exposition. Arbeitsmed, Sozialmed, Präventivmed 15:254–260
Krigman MR, Bouldin TW, Mushak P (1980) Lead. In: Spencer PS, Schaumburg HH (eds) Experimental and clinical neurotoxicology. Williams and Wilkins, Baltimore/London
Lehnert G, Szadkowski D (1983) Die Bleibelastung des Menschen. Verlag Chemie, Weinheim
Lilis R, Fischbein A, Eisinger J, Blumberg WE, Diamond S, Anderson HA, Rom W, Rice C, Sarkozi L, Kon S, Selikoff SJ (1977) Prevalence of lead disease among secondary lead smelter workers and biological indicators of lead exposure. Environ Res 14:225–285
Low PA, Dyck PJ (1977) Increased endoneurial fluid pressure in experimental lead neuropathy. Nature 269:427–428
Ludin HP (1981) Praktische Elektromyographie. Enke, Stuttgart
Mumenthaler M, Schlick H (1982) Läsionen peripherer Nerven. Thieme, Stuttgart
Nottbohm L, Seubert A, Seubert S, Laurig W, Brockmann W (1980) Epidemiologische Untersuchungen über die Beziehung zwischen beruflicher Bleiexposition und Bleiaufnahme. Arbeitsmed, Sozialmed, Präventivmed 15:26–31
Paulev P-E, Gry C, Døssing M (1979) Motor nerve conduction velocity in asymptomatic lead workers. Int Arch Occup Environ Health 43:37–43
Sachs L (1978) Angewandte Statistik. Springer, Berlin Heidelberg New York, S 351 ff.
Schaller KH, Schiele R (1978) Comparison of fluorometric micromethods for analyzing erythrocytic porphyrins (EP). In: Doss M (ed) Diagnosis and therapy of porphyrias and lead intoxication
Schaller KH, Valentin H (1980) Biologische Arbeitsstoff-Toleranz-Werte: BAT-Werte für Blei und seine anorganischen Verbindungen. Arbeitsmed, Sozialmed, Präventivmed 12:277–287
Schiele R, Wagner HM, Krause CH (1978) Die freien Erythrocytenporphyrine (FEP) als Wirkungsparameter und ihre Wertigkeit im Vergleich zu anderen Belastungskriterien. Blei und Umwelt II, BGA-Bericht 1/78:138–144
Seppäläinen AM, Hernberg S (1972) Sensitive technique for detecting subclinical lead neuropathy. Br J Ind Med 29:443–449
Seppäläinen AM, Tola S, Hernberg S, Kock B (1975) Subclinical neuropathy at “safe” levels of lead exposure. Arch Environ Health 30:180–183
Seppäläinen AM, Hernberg S, Kock B (1979) Relationship between blood lead levels and nerve conduction velocities. Neurotoxicology 1:313–332
Seppäläinen AM, Hernberg S (1982) A follow-up study of nerve conduction velocities in lead exposed workers. Neurobehav Toxicol Teratol 4:721–724
Spencer PS, Schaumburg HH (1980) Experimental and clinical neurotoxicology. Williams and Wilkins, Baltimore/London
Spivey GH, Baloh RW, Brown CP, Browdy BL, Campion DS, Valentine JL, Morgan DE, Culver BD (1980) Subclinical effects of chronic increased lead absorption — a prospective study. J Occup Med 22:607–612
Seubert S, Seubert A (1977) Bestimmung der Erythrozyten-Porphyrine. Dtsch Med Wochenschr 102:1882–1884
Takeuchi H, Takahashi M, Hara I, Hashimoto K, Suenaka T, Genba H (1975) An electrophysiological study on peripheral nerve injuries of workers handling lead. Jpn J Ind Health 17:467–474
Triebig G, Reichenbach Th, Schaller KH (1980) Messungen der Nervenleitgeschwindigkeit bei beruflich blei-exponierten Personen. Arbeitsmed. Kolloquium, 20. Jahrestagung der Dtsch. Gesellschaft in Innsbruck am 27. bis 30. April 1980. Gentner Verlag, Stuttgart
Triebig G, Schaller KH, Valentin H (1981) Untersuchungen zur Neurotoxizität von Arbeitsstoffen. I. Messung der motorischen und sensorischen Nervenleitgeschwindigkeit bei beruflich Quecksilber-belasteten Personen. Int Arch Occup Environ Health 48:119–129
Triebig G, Büttner J (1983) Neurotoxische Arbeitsstoffe: I. Metalle und ihre Verbindungen. Eine Literaturübersicht der Jahre 1970–1981. Zbl Bakt Hyg I AN [Orig B] 177:11–36
WHO (1977) Environmental health criteria. Lead. Genf
Zielhuis RL (1977) Second international workshop permissible levels for occupational exposure to inorganic lead. Int Arch Occup Environ Health 39:59–72
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With Grants from the Deutsche Forschungsgemeinschaft, Bonn (Project no. Va 23/19-1)
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Triebig, G., Weltle, D. & Valentin, H. Investigations on neurotoxicity of chemical substances at the workplace. Int. Arch Occup Environ Heath 53, 189–204 (1984). https://doi.org/10.1007/BF00398813
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DOI: https://doi.org/10.1007/BF00398813