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Biomedical subjects

G Triebig

Publications and source records attributed to G Triebig.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Carcinogenic industrial substances--a review of the present information].

The potential carcinogenic risks of chemical substances at the workplace show increasing importance in occupational and environmental medicine, but the problems are also discussed controversially. Based on national and international literature estimations according the portions of occupational cancer are given. In accordance with former estimations from our institute, it is concluded, that 1-2% of all cancer deaths are caused by work and profession. A review of data from newer literature shows, that the numbers of chemicals with carcinogenic potency vary considerably. This is mainly due to the largely unknown mechanism of carcinogenesis, aspects of syncarcinogenesis and cocarcinogenesis as well as the different evaluation of mutagenicity-, short-term- and animal-tests on the one hand and of epidemiologic as well as casuistic studies on the other hands regarding carcinogenicity of chemicals for humans. In this context, the importance of epidemiologic studies for detecting unknown cancerogenic risks for humans is emphasized. In the field of occupational medicine it is relevant to differ between compensation and prevention. According to this aspects, for compensation of a malignant tumor as an occupational disease, more strict criterias must be fulfilled to objectify the carcinogenicity of a substance for humans than for preventive measures. On the basis of the monographs as well as reviews of the International Agency for Research on Cancer (IARC) the single substances, mixture of substances and industrial processes with proven or probably carcinogenicity for humans are given. In comparison to the monograph of Hueper from 1963 it is concluded, that until now no critical increase of carcinogenic substances at the workplace has occurred. For preventive efforts at the workplace, the medical examinations are important. These are based on various regulations by law or by German Employers Liability Insurance. In conclusion, recommendations and demands are given regarding prevention, evaluation and compensation of malignant diseases as well as detection of unknown carcinogenic risks for humans at the workplace.

Carcinogens↗
PubMed1985

Investigations on neurotoxicity of chemical substances at the workplace. VII. Longitudinal study with determination of nerve conduction velocities in persons occupationally exposed to styrene.

The aim of this longitudinal study was to investigate whether long-term exposure to styrene is associated with functional disorders of the peripheral nervous system. Eleven workers (age: 24 to 54 years) of a polyester resin boat industry were studied neurophysiologically and biochemically in 1980 and 1983. The duration of styrene-exposure varied from 3 to 7 years, with a median of 4 years. The control group was comprised of 11 non-styrene-exposed workers of similar age. Air Monitoring with passive samplers was performed on different days for each person. The mean styrene concentrations were 114, 97 and 92 ppm respectively and therefore in the magnitude of the current MAK-value of 100 ppm in the Federal Republic of Germany (FRG). For Biological Monitoring styrene in blood (S-B) and mandelic acid (MA) as well as phenylglyoxylic-acid (PGA) in urine were determined in post-shift samples. The median values for MA at four different sampling times were 816, 1660, 1101 and 1224 mg/g creatinine and for PGA 200, 273, 342 and 336 mg/g creatinine respectively. These levels were below the current "Biologischer Arbeitsstoff Toleranzwert (BAT-Wert)" for MA (2000 mg/l) and MA + PGA (2500 mg/l). The S-B concentrations ranged from 0.05 mg/l to 3.26 mg/l, with mean values of 0.92 and 0.70 mg/l. The nerve conduction velocities (NCV) of motor and sensory nerve fibers (N. ulnaris and/or N. medianus) showed no significant differences between styrene-exposed workers and age-matched control persons. There were no hints of "dose-effect-relationships" by correlation analyses. Furthermore the follow-up determination revealed no significant changes regarding NCV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Severe lead polyneuropathy. Clinical course and prognosis--case report].

The case of a 46 years old bricklayer is described, who developed a severe lead-polyneuropathy. The cause of the neurological disease was the dermal application of leadacetate -solutions because of chronic eczema of the hands over several years. There was a delayed manifestation of the peripheral neuropathy. Besides the typical pareses of the N. radialis also a slowing of nerve conduction velocities of sensible fibers were objectified by neurophysiological measurements. After decorporation -treatment with CaNa2EDTA there was a clear improvement ten months later. The anemia caused by lead had recovered completely. The aspects and course of the disease are discussed regarding results in literature. It is concluded, that during a severe lead polyneuropathy besides motor also sensory nerve fibers can be involved.

Edetic Acid↗
PubMed1984

[Neurotoxicity of chemical substances in the workplace. VI. Longitudinal study of persons occupationally exposed to mercury].

A longitudinal study was performed on eleven persons, who had been chronically exposed to mercury (Hg) (3 to 31 years, median 5 years) in 1977, 1980 resp., and 1982. During their work in a chemical plant they had had contact to elemental Hg and various inorganic as well as organic mercury compounds. The main purpose of the investigation was the evaluation of possible adverse effects to the nervous system caused by mercury. The internal Hg-exposure was measured by mercury analysis in blood (Hg-B) and in urine (Hg-U). Furthermore "time-weighted average" levels were calculated on the basis of former Hg-determinations from 1974 to 1982. For Hg-B these values ranged between 26 and 104 microgram/dl (median 42 microgram/l) and for Hg-U between 73 and 434 microgram/g creatinine (median 233 microgram/g creatinine) (upper normal levels: Hg-B: 5 microgram/l; Hg-U: 5 microgram/g creatinine). The determination of the peripheral nerve conduction velocities (NLG) of motor and sensory fibers as well as the registration of somatosensory-evoked potentials (SEP) revealed no pathological results, except one borderline case. The NLG- and SEP-values did not significantly differ from those of non exposed persons or from those of former NLG-determinations. No correlations were found between indicators of Hg-exposure and neurophysiological parameters regarding dose-effect-relationship. Statistical differences resulted in the time-dependent test of the psychological test battery performed in comparison to age-matched control persons of equal socio-economous status. In additional, significant relationships were calculated between Hg-exposure and these tests. Considering the inter- and intraindividual variations of the psychological test results, there were no substantial alterations in the total findings over the observed period except for one case. Workers with Hg-exposure below the current BAT-values (Hg-B 50 microgram/l, Hg-U 200 microgram/l) showed no pathological findings in the neurological, neurophysiological and neuropsychological examinations.

Adult↗
PubMed1984

Investigations on neurotoxicity of chemical substances at the workplace. V. Determination of the motor and sensory nerve conduction velocity in persons occupationally exposed to lead.

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) delta-Aminolevulinic acid dehydratase (ALA-D) and (4) delta-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 micrograms/dl (54 micrograms/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 micrograms/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 micrograms/dl. From our study it is concluded that chronic lead exposure resulting in blood-lead levels of below 70 micrograms/dl is no occupational risk causing a functionally significant slowing of nerve conduction velocities.

Adult↗
PubMed1984

Indoor air pollution by smoke constituents--a survey.

A review of the literature on the present state of knowledge about the topic "indoor air pollution by smoke constituents" has been made. While consideration is given to standard bibliographic works and more recent reviews, an evaluation of the results of field studies and experimental investigations carried out under realistic conditions is also made. The selection of the tobacco smoke constituents discussed here was based on environmental and toxicological aspects. The following substances are considered in detail: carbon monoxide, nitrogen oxides, formaldehyde, acrolein, ammonia, phenol, hydrogen cyanide, sulfur dioxide, cadmium, nickel, nicotine, some volatile nitrosamines, polycyclic aromatic hydrocarbons, and respirable particulates. The smoke constituent concentrations in the literature are presented in tables. The results are evaluated and discussed with respect to the maximum allowable concentrations presently valid in the Federal Republic of Germany.

Acrolein↗
PubMed1984

The influence of passive smoking on pulmonary function--a study of 1,351 office workers.

Until now it has been difficult to ascertain how much passive inhalation of tobacco smoke affects bronchopulmonary function. To answer this question, an investigation involving 1,351 white collar workers was carried out. Information about active and passive tobacco smoke exposure was obtained by a standardized questionnaire. This made it possible to subdivide the overall group into five subgroups: Never smokers, passive smokers, ex-smokers, current smokers, and other smokers. Forced expiratory vital capacity (FVC) and maximal expiratory flow-volume (MEFV) curves were used for lung function analysis. From these curves FVC, forced mid-expiratory flow (FEF 25/75), forced end-expiratory flow (FEF 75/85), and maximal mid-expiratory flow (MEF 25/75) were determined and standardized for sex, age, height, and body weight. Passive smokers evaluated by this method showed essentially no decrease in parameters describing ventilatory function. It is concluded from the dose-and time-effect relationships obtained in active smokers between the lung function parameters and the duration of tobacco smoke exposure on the one hand and the daily consumption of cigarettes on the other that passive smoking in small doses may have no essential effect on pulmonary function.

Adult↗
PubMed1983

[Neurotoxicity of workplace substances. IV. Determination of motor and sensory nerve conduction velocity in persons exposed to solvent mixtures].

A cross-sectional study was performed on 112 workers with long-term exposure (mean 5 years) to a mixture of organic solvents (aliphatic and aromatic hydrocarbons, halogenated hydrocarbons). The purpose of the study was to examine whether this exposure had caused impairment of the peripheral nervous function. Forty-six workers with non-occupational risk of peripheral neuropathy (previous diseases, alcohol abuse, medication) were excluded. As a basis for the evaluation of solvent exposure, we carried out "environmental and biological monitoring" for some solvents. In no case did a hint of a manifest disorder of the nervous system exist. By comparison with age-matched controls, the mean sensory conduction velocity (NCV) of the N. ulnaris of the exposed persons was significantly reduced by 1.5 m/s. The maximal motor NCV of the N. ulnaris and the sensory NCV of the N. medianus did not differ significantly. The differentiation of the workers relating to short-(7-24 months), middle-(25-60 months)- and long-(more than 60 months) term exposure showed that the sensory NCV of the N. ulnaris was slowed only for persons with middle- and long-term histories of solvent exposure. Assessing the individual neurophysiological status the frequency of pathological NCV improved from 12 to 36% in relation to increasing time of exposure. Overall 15 of 66 workers (23%) had abnormal NCVs. The findings are discussed according to data given in literature.

Humans↗
PubMed1983

[Neurotoxic occupational substances: I. Metals and their compounds. A literature review of the years 1970 to 1982].

The knowledge of the neurotoxicity to the peripheral nervous system of arsenic, lead, thallium and mercury as well as their compounds is reviewed according to the literature of the period 1970-1982. - First acute and chronic intoxications are described with special reference of the neurological symptoms. Then we review the results of electromyographic, neurophysiological and histological investigations. Field studies in occupationally exposed groups and evaluation of dose-response-relationships are specified in detail. Further the presented results are discussed according to aspects in occupational medicine. The following conclusions can be drawn: Neuropathies after arsenic intoxications are characterized by symmetric sensory symptoms as usually numbness and paresthesiae of the distal extremities, but the neurophysiological and histological studies showed a great variety of results. In a former study a significant dose-response-relationship between arsenic load and evidence of neuropathy in workers was demonstrated. The onset of impairments of the peripheral nervous system caused by chronic lead exposure is discussed controversially. Some reports showed a dose-response-relationship between a slowering of nerve conduction velocities and an increase of the lead body burden. Proposals of threshold values ranged between 50 to 80 micrograms lead/dl blood. Other authors did not confirm these results. Longitudinal studies are, with one exception, not available at present. Thus a relevant evaluation, particularly regarding relevance and prognosis of a mild slowering of nerve conduction velocity, can not be given now. The neurotoxicity of mercury and its compounds is well demonstrated. In case of the metal and the inorganic compounds a direct damage of the peripheral nerve is possible, whereas for organic compounds the pathophysiological mechanism is unclear. Studies concerning dose-response-relationships as well as evaluation of threshold values in chronically exposed workers are limited. It seems at present not possible to define a threshold value for the neurotoxic effects of mercury according to peripheral nervous system. Thallium caused peripheral neuropathy is described in many casuistics But to our knowledge there are no reports of neurophysiological studies in occupationally exposed groups.

Adult↗
PubMed1983

[Neurotoxic workshop materials: II. Organic substances--a review of the years 1970 to 1982].

This paper summarizes the knowledge and recent research of some organic neurotoxic substances at the workplace concerning peripheral nervous system. The review covers the substances: acrylamide, n-hexane, methyl-n-butylketone, n-pentane, n-heptane, carbondisulfide, styrene, toluene, trichloroethylene, tri-ortho-cresylphosphate and other organophosphorus compounds, polyhalogenated and complex organic compounds and solvent-mixtures. First the chemical and physical properties, the toxicokinetic and biotransformation as well as possibilities of exposure at the workplace are given. Following the characteristics after acute and chronic intoxications. The effects to the peripheral nervous systems due to short- and longtime exposure of the substance are described. Field studies in exposed workers and neurophysiological investigations with evaluation of dose-effect-relationships are reviewed especially. Each section is discussed and evaluated in respect to occupational medicine.

Acrylamide↗
PubMed1982

[Investigations on neurotoxicity of chemical substances at the workplace. III. Determination of the motor and sensory nerve conduction velocity in persons occupationally exposed to trichloroethylene].

We studied 31 employees (26 men, five women) from three firms, between the ages of 16 and 56 years, who had been exposed to trichloroethylene (TRI) from 1 month to 35 years, mean 7 years. To objectify the actual solvent-exposure we performed "biological monitoring" and determined TRI- and the metabolites trichloroethanol (TCE) and trichloroacetic acid (TCA) in blood- and/or urine-samples. The following concentrations were found in the urine-samples: TCE 19.0-357.0 mg/g creatinine, median 90.0; TCA 2.0-201.0 mg/g creatinine, median 48.0; TTC (TCE + TCA) 31.0-416.0 mg/g creatinine, median 112.5. Additionally three results of former urine-analyses in the period 1978-1980 from 10 workers were obtained to calculate "time-weighted-average (TWA)"-levels (TWA-TTC in urine: 53-640 mg/g creatinine). Nerve conduction velocity (NLG)-measurements of motor and/or sensory fibers of the ulnar and median nerve were performed to test peripheral nerve function. Seven employees were excluded. They had possible competitive risks of peripheral neuropathy, or were of less than 10 months exposed. For controls we examined 24 healthy persons of identical sex and age (matched pairs), but without known risks of a peripheral neuropathy. In comparing the nerve conduction velocities there were no significant differences between TRI-exposed and non-exposed persons. Correlation analyses and the individual assessment of the data concerning exposure/dose and effect revealed no signs of a "dose-effect-relationship".

Adolescent↗