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Biomedical subjects

J Angerer

Publications and source records attributed to J Angerer.

At least 127 records · Page 7Linked to original sources
PubMed1987

Occupational chronic exposure to metals. I. Chromium exposure of stainless steel welders--biological monitoring.

External and internal chromate exposure of 103 stainless steel welders who were using manual metal are welding (MMA), metal inert gas welding (MIG) and both methods, were measured by ambient and biological monitoring. At the working places the maximum chromium trioxide concentrations were 80 micrograms/m3. The median values were 4 micrograms/m3 (MMA) and 10 micrograms/m3 (MIG). The median chromium concentrations in erythrocytes, plasma and urine of all welders were less than 0.60, 9.00 and 32.50 micrograms/l. For biological monitoring purposes, chromium levels in erythrocytes and simultaneously in plasma seem to be suitable parameters. According to our results, chromium levels in plasma and urine in the order of 10 and 40 micrograms/l seem to correspond to an external exposure of 100 micrograms chromium trioxide per cubic metre, the technical guiding concentration (TRK-value). Chromium concentrations in erythrocytes greater than 0.60 micrograms/l indicate an external chromate exposure greater than the TRK-value.

Adult↗
PubMed1987

Sister chromatid exchange and chromosomal breakage in pentachlorophenol (PCP) exposed workers.

A cytogenetic study was performed on 20 healthy workers exposed to pentachlorophenol (PCP) in concentrations ranging from 1.2 to 180 micrograms/m3 (Maximum Concentration at the workplace is 500 micrograms/m3) for 3 to 34 years. PCP was determined in the blood plasma of all probands, yielding concentrations between 23 and 775 micrograms/l (Biological Tolerance Value is 1000 micrograms/l). In vitro PCP up to 90 mg/l was added to phytohaemagglutinin stimulated lymphocytes of normal healthy donors without any effect on sister chromatid exchange (SCE) or chromosomal aberrations (CA), whereas a slowdown of cell proliferation could be detected in the presence of 60 mg PCP/l. In vivo we neither observed a relation between PCP concentrations and the number of SCE nor an increase of CA.

Adult↗
PubMed1985

Exposure to fluorotrichloromethane (R-11).

Three volunteers were exposed to fluorotrichloromethane (R-11) under experimental conditions. Solvent levels in ambient and alveolar air, in blood and urine were measured. The mean concentration of R-11 in ambient air was 657 ml/m3. The average values of pulmonary retention and solvent levels in alveolar air and blood were 18.2%; 537 ml/m3 and 2.8 mg/l. Inter-individual variations of these parameters are negligible. R-11 concentrations in urine--in contrast to blood or alveolar air--depend on the dose taken up. After termination of exposure, R-11 concentrations in alveolar air and in blood are excreted with biological half-lives of seven and eleven minutes respectively during the first phase of elimination and with 1.8 and 1.0 h respectively during the second phase of elimination. Though ambient monitoring should, in most cases, be sufficient for the prevention of occupational diseases, the R-11 concentration in alveolar air seems to be the best parameter if biological monitoring seems to be necessary.

Adult↗
PubMed1985

Occupational chronic exposure to organic solvents. XI. Alkylbenzene exposure of varnish workers: effects on hematopoetic system.

Thirty-five spraymen, who were varnishing vehicles with alkyd-, phenol- and polyestervarnishes, which were dissolved in solvent mixtures mainly containing o-, m-, p-xylene and ethylbenzene, have been investigated. The concentrations of these solvents in air were 2.1, 7.9, 2.8 and 4.0 ppm on average. The levels of alkylbenzenes in blood and those of their metabolites in urine have been determined. At two of the six working places the spraymen were additionally exposed to n-butanol, respectively 1,1,1-trichloroethane, and several C9-aromatic hydrocarbons. Some of the lacquers contained lead pigments. Alterations of blood cell counts have been observed under the described conditions of exposure. On average the number of lymphocytes was higher than that of segmented granulocytes. Erythrocytes and hemoglobin level of the spraymen were lower than those of the controls.

Adult↗
PubMed1985

Occupational chronic exposure to organic solvents. XII. O-cresol excretion after toluene exposure.

Thirty-five printing workers were investigated according to their external and internal exposure to toluene. The concentration of toluene in the air of the working place was determined using stationary air sampling and gas chromatography. To determine the levels of toluene in blood as well as the concentrations of o-cresol, hippuric acid, and phenol in urine, biological specimens were collected at the end of exposure. The parameters were determined by gas chromatography and gas chromatography/mass spectrometry. According to our results, o-cresol concentrations higher than 5.3 mg per litre of post-shift urine might indicate an external exposure higher than the present MAK-value of 200 ppm.

Adult↗
PubMed1985

Biological monitoring of workers exposed to organic solvents--past and present.

The development of biological monitoring for persons exposed to organic solvents is described. The advantages of this supervision strategy, as well as the reservation against it, are discussed. With the target organs of organic solvents, matrices and parameters for biological monitoring taken into consideration, the following recommendations can be given: the determination of solvent level in blood or alveolar air as a substitute is obligatory for the biological monitoring of organic solvents (the toxic stress of the target organ--the brain--is reflected this way); metabolites have to be determined also when they or their predecessors impair other organs. The discussion of chemical analysis, interference and influencing factors, as well as biological limit values, leads to suggestions of how to interpret the results of biological monitoring. Beyond the estimation of the health risk of the individual worker, the results also have to be interpreted on a group basis. Only in this way can all information on biological monitoring be used to the advantage of prevention. In summary, today biological monitoring is possible for most of the organic solvents. Estimation of health risk in the case of simultaneous exposure to several solvents is still not possible. Parameters measuring toxic strain must be established. The various social groups have to be convinced of the advantages of biological monitoring.

Environmental Monitoring↗
PubMed1984

Determination of cobalt in biological materials by voltammetry and electrothermal atomic absorption spectrometry.

For industrial purposes cobalt is used to a large extent. About 2,300 persons are occupationally exposed to this carcinogenic metal in Western Germany. As reliable analytic methods for biological monitoring are not available we developed procedures for analyzing cobalt in whole blood and urine by using two independent methods, voltammetry and ETAAS. For ETAAS-analysis of urine the cobalt content is chelatized and extracted in an organic solvent. This clean-up step enables us to calibrate with aqueous standards.--Samples of whole blood are directly injected into the graphite tube after being diluted with a homogeniziser. For their gentle thermal decomposition we use a temperature/time programme containing six steps. Both kinds of sample treatments are uncomplicated and permit routine applications. For voltammetric determination of cobalt in urine and blood the biological material must be completely mineralized. The dry residue is dissolved in a NH4Cl/NH3 solution. Cobalt is chelatized with 2,3-butanedione-dioxime and preconcentrated by adsorption at the hanging mercury electrode. By scanning the potential into negative direction the cobalt complex is reduced. The resulting signal can be used for the quantitative determination. For comparison of both methods we have analyzed blood and urine samples of occupationally exposed persons. We found very good correlations with a statistical significance at the level of 0.01%.

Cobalt↗
PubMed1983

Occupational exposure to hexachlorocyclohexane. VI. Metabolism of gamma-hexachlorocyclohexane in man.

Metabolism of gamma-Hexachlorocyclohexane (HCH) was studied examining 21 workers producing this insecticide. Using gas chromatography in combination with ECD and mass spectrometry 14 mono-, di-, tri- and tetrachlorophenols were identified in the urine samples of the workers. Seven dihydroxychlorobenzenes of still unknown configuration were detected by mass spectrometry. Ten of the more abundant metabolites, di-, tri- and tetrachlorophenols were determined quantitatively in all urine samples. 2,4,6-; 2,3,5- and 2,4,5-trichlorophenol turned out to be the main metabolites of gamma-HCH. They were excreted in nearly equal quantities. On account of their potential liver toxicity, the determination of chlorophenols in urine should be part of a biological monitoring program of HCH-exposed persons.

Adult↗
PubMed1982

Occupational chronic exposure to organic solvents. X. Biological monitoring parameters for methanol exposure.

Twenty persons occupationally exposed to methanol were examined according to their methanol levels in blood and urine and their formic acid excretion. An 8-h exposure to a methanol concentration of 93 ml/m3 (geometric mean) in the air at the working area caused average methanol levels in blood and urine of (8.9 +/- 14.7) mg/l and (21.8 +/- 20.0) mg/l, respectively, and a mean formic acid excretion of (29.9 +/- 28.6) mg/l. These average concentrations for the exposed group showed statistically significant increases compared to those of a control group. For the methanol workers we succeeded in correlating their methanol levels in blood and urine. When considering the possible application of these parameters for biological monitoring, difficulties were encountered, especially for the individual case from the overalapping range in the concentrations of exposed and unexposed persons for each of the applied parameters. This range is minimum for the methanol concentration in urine. About 80% of the urinary levels from the methanol workers lies above the upper limit within the control group range. Based on our results a rough estimate shows the corresponding methanol content in urine to be about 40 mg/l for an 8-h exposure at 200 ml/m3 (German MAK value).

Formates↗
PubMed1981

Occupational exposure to hexachlorocyclohexane. V. Gas chromatographic determination of monohydroxychlorobenzenes (chlorophenols) in urine.

A sensitive and specific gas chromatographic method is described for the simultaneous determination of ten chlorinated phenols that appear in the urine of persons exposed to hexachlorocyclohexane (HCH). The phenolic compounds in the urinary samples are hydrolysed in an acidic medium and derivatised with acetic anhydride. This sample treatment permits routine application. The stationary phase (8% DC 200 on Chromosorb G AW-DMCS) possesses a high separating capability for the acetic esters of the chlorophenols. The detection limits lie between 4.9 and 18.6 micrograms/l and allow determinations even in the environmentally interesting concentration range. The recoveries determined using aqueous standards range between 87 and 119% and the relative standard deviations are between 4.4 and 10.1%.

Chlorophenols↗
PubMed1981

[A practical method for the determination of cobalt in urine (author's transl)].

A simple and reliable analytical method for the determination of cobalt in human urine is described. After an extraction step, cobalt is measured with the aid of flameless atomic absorption spectrometry. The detection limit is 0.1 microgram cobalt per litre urine. The recovery of cobalt, determined by the addition of a defined cobalt concentration to the urine, is in the range of 101-107%. The relative standard deviation is between 3.4 and 8.6%. In the urine of persons not professionally exposed to cobalt, concentrations between 0.1 and 0.75 microgram/l were found.

Cobalt↗
PubMed1980

Occupational exposure to hexachlorocyclohexane. I. Body burden of HCH-isomers.

In a lindane (gamma-hexachlorocyclohexane = gamma-benzenehexachloride)-producing factor 57 workers were studied with regard to their blood levels of the three hexachlorocyclohexane isomers: alpha-, beta-, and gamma-HCH. The TLV-TWA (MAK value 1979) for gamma-HCH of 0.5 mg/m3 was not exceeded at any of the workplaces where HCH is synthesized and purified to lindane. Additionally, in some of the workers samples of s.c. adipose tissue were taken for determination of HCH-isomer content. An external group of 20 clerks was examined in the same way for control purposes. In contrast to the control persons, none of whom had HCH-concentrations in serum above the respective detection limits, the values determined in serum of the exposed workers were in the following ranges: alpha-HCH: 10-273 microgram/1, beta-HCH: 17-760 microgram/l, and gamma-HCH: 5-188 microgram/1. Of special interest is the observation of a significant increase of beta-HCH-concentration in serum with the time of employment in lindane production, indicating a pronounced accumulation of this substance in the human organism. Concentrations of this isomer in s.c. adipose tissues were about 300-fold higher than in serum. A significant correlation between both parameters could be established. The results of this study show that adherence to the TLV-TWA of gamma-HCH is not sufficient for control of HCH-exposure. Furthermore, biological monitoring of exposed workers is necessary taking into account the three more important isomers alpha-, beta-, and gamma-HCH.

Adipose Tissue↗