Search PubMed⌕ Search

Biomedical subjects

J Angerer

Publications and source records attributed to J Angerer.

At least 109 records · Page 6Linked to original sources
PubMed1994

Concentrations of benzene in blood and S-phenylmercapturic and t,t-muconic acid in urine in car mechanics.

Different parameters of biological monitoring were applied to 26 benzene-exposed car mechanics. Twenty car mechanics worked in a work environment with probably high benzene exposures (exposed workers); six car mechanics primarily involved in work organization were classified as non-exposed. The maximum air benzene concentration at the work places of exposed mechanics was 13 mg/m3 (mean 2.6 mg/m3). Elevated benzene exposure was associated with job tasks involving work on fuel injections, petrol tanks, cylinder blocks, gasoline pipes, fuel filters, fuel pumps and valves. The mean blood benzene level in the exposed workers was 3.3 micrograms/l (range 0.7-13.6 micrograms/l). Phenol proved to be an inadequate monitoring parameter within the exposure ranges investigated. The muconic and S-phenylmercapturic acid concentrations in urine showed a marked increase during the work shift. Both also showed significant correlations with benzene concentrations in air or in blood. The best correlations between the benzene air level and the mercapturic and muconic acid concentrations in urine were found at the end of the work shift (phenylmercapturic acid concentration: r = 0.81, P < 0.0001; muconic acid concentration: r = 0.54, P < 0.05). In conclusion, the concentrations of benzene in blood and mercapturic and muconic acid in urine proved to be good parameters for monitoring benzene exposure at the workplace even at benzene air levels below the current exposure limits. Today working as a car mechanic seems to be one of the occupations typically associated with benzene exposure.

Acetylcysteine↗
PubMed1994

[The importance of formic acid excretion in the urine for environmental and occupational medicine questions].

The suitability of the formic acid excretion in the urine as a parameter for the biological monitoring of inhalational exposure to formaldehyde is discussed controversially. We investigated persons not occupationally exposed to formaldehyde (n = 70) to determine possible influencing factors on the physiological excretion of formic acid. Following this we carried out a study on medical students (n = 30), who during an anatomical dissection course were exposed to a short but intensive inhalational exposure to formaldehyde, as well as investigations on employees of a pathological-anatomical laboratory (n = 8) in order to observe the course of the formic acid excretion in the urine during a working week with a continuous exposure to formaldehyde below or within the range of the MAK value (0.5 ppm). It was seen that the formic acid excretion in the urine with non-exposed persons is subject to considerable inter and intraindividual fluctuations (at a maximum by a factor of 30). In addition to differences in the endogenous formation of formates an important influencing factor is probably the uptake of food containing formic acid or its precursors. A value of 23 mg formic acid/g creatinine is given as the upper norm level (95th percentile) of adults. In the groups who were exposed to formaldehyde, in some cases considerably above the MAK value, we were able to detect no significant increase in the formic acid concentration in the urine. After a short but intensive exposure to formaldehyde (0.32-3.48 ppm) the formic acid concentration in the urine did not change significantly with an average formic acid concentration in the urine before exposure of 6.5 mg/g creatinine (central 50% range: 3.5-14.2 mg/g creat.) and after exposure of 6.0 mg/g creatinine (central 50% range: 4.4-10.9 mg/g creat.). There was no significant relationship between the individual change in the formic acid concentration in the urine (in mg/g creatinine) and the inhalational exposure to formaldehyde determined through personal air sampling (r = 0.079). In the course of a working week with a continuous exposure to formaldehyde (0.03-0.83 ppm) there was after relating the values to creatinine a continuous increase in the median to 22.3 mg/g creat. with a starting value of 8.7 mg/g creat. The change proved, however, for the number of cases investigated not to be significant. In particular there was no linear correlation detectable between the individual changes in the formic acid excretion in the urine and the formaldehyde concentrations in the breathing zone determined by personal air sampling.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Inhalation↗
PubMed1994

[Chlorophenols in urine as an environmental medicine monitoring parameter].

Chlorophenols occur ubiquitously in the environment. They are taken up as such in man or are formed in intermediary metabolism e.g. from chlorobenzenes. In particular pentachlorophenol (PCP) is one of those chemical substances used up to the early 70's as a component of wood preservatives also indoors; for many years it has been at the centre of discussion about the environment. Mono, di, tri and tetrachlorophenols as well as pentachlorophenol occur in the urine in the general population often in surprisingly high concentrations. An increased chlorophenol excretion under certain circumstances also indicates an increased dioxin exposure (pre-dioxins). Possible sources of emission and routes of absorption for corresponding organochlorine compounds can be found in industry, agriculture and also private households. Environmental analysis in the air, in earth or dust do not allow any evaluation of health risks. Only biological monitoring with qualitative and quantitative determination of the actual concentration of the substance taken up by the organism allows a reliable estimation of the individual health risk. The background exposure of the general population not occupationally exposed to organochlorine compounds can be used for the determination of so-called norm values. For the determination of the chlorophenol spectrum 50 ml urine are necessary. The following values can be given as reference values for the most important chlorophenols: 4-monochlorophenol: 7.5 micrograms/l, 2.4-dichlorophenol and 2.5-dichlorophenol: 33.6 micrograms/l, 2.4.6-trichlorophenol: 4.7 micrograms/l, 2.4.5-trichlorophenol: 4.5 micrograms/l, 2.3.4.6-tetrachlorophenol and 2.3.5.6-tetrachlorophenol: 22.0 micrograms/l, pentachlorophenol 9.0 micrograms/l urine.

Chlorophenols↗
PubMed1993

Occupational chronic exposure to organic solvents. XIV. Examinations concerning the evaluation of a limit value for 2-ethoxyethanol and 2-ethoxyethyl acetate and the genotoxic effects of these glycol ethers.

Two groups of workers occupationally exposed to glycol ethers in a varnish production plant or the ceramic industry were examined. For 19 persons the external and internal exposure was assessed on the Monday and Tuesday after an exposure-free weekend. In the varnish production area the concentrations of 2-ethoxyethanol (EE), 2-ethoxyethyl acetate (EEAc), and 2-butoxyethanol (BE) in air averaged 2.9, 0.5, and 0.5 ppm, respectively, on the Monday, and 2.1, 0.1, and 0.6 ppm, respectively, on the Tuesday. At the same workplaces the mean urinary 2-ethoxyacetic acid (EAA) and 2-butoxyacetic acid (BAA) concentrations were 53.2 and 0.2 mg/l on Monday preshift and 53.8 and 16.4 mg/l on Tuesday postshift. The results show that glycol ethers are very well absorbed through the skin. Therefore biological monitoring is indispensable. To study the kinetics of the toxic metabolite, 17 persons were examined for their excretion of EAA in urine during an exposure-free weekend. The median values of the calculated half-times were 57.4 and 63.4 h, respectively, which are longer than the values presented in literature until now. According to our calculations the limit value should not exceed 50 mg EAA per liter of urine, which is the current German biological tolerance value (BAT value) for EAA in urine. The maximum concentration value at the workplace (MAK value) for EE and EEAc in air should be revised. Finally, the subjects from the varnish production plant as well as a group of reference persons were studied for cytogenetic effects of glycol ethers (sister chromatid exchange, micronucleus test). Such effects could not be detected.

Acetates↗
PubMed1992

Determination of aromatic hydrocarbons and their metabolites in human blood and urine.

Methods for the biological monitoring of aromatic hydrocarbons and their metabolites in the human blood and urine are reviewed. For the determination of the unchanged aromatic hydrocarbon in blood, gas chromatographic head-space analysis is recommended. The metabolites can be monitored by photometric, thin-layer chromatographic, high-performance liquid chromatographic and gas chromatographic methods. For the assessment of health risks caused by aromatic hydrocarbons, reference values and occupational limit values, expressed as biological tolerance values and biological exposure indices, have to be considered.

Benzene↗
PubMed1992

Chronic occupational exposure to organic solvents. XV. Glycol ether exposure during the manufacture of brakehoses.

Twenty-two persons (20 men and 2 women) were examined for their external and internal exposure to the glycol ether 1-methoxypropan-2-ol (PGME) during the production, leak testing and mounting of brakehoses. For the measurement of external exposure, personal air monitoring was the method of choice. Average concentrations of PGME of 82.2 mg/m3 (22.3 ppm), 68.6 mg/m3 (18.6 ppm) and 11.3 mg/m3 (3.1 ppm) were found in the air of the brakehose production, leak test and mounting areas, respectively. For the estimation of internal exposure to PGME, this glycol ether was measured in both urine and blood. The biological samples were taken post-shift. The highest internal exposure levels were found in the brakehose production section and in the leak test area. The average post-shift concentrations for PGME in workers in the brakehose production section were 4.6 mg/l in urine and 13.5 mg/l in blood; the corresponding figures for workers in the leak test area were 4.2 mg/l in urine and 11.0 mg/l in blood. In blood and urine samples of workers engaged in the mounting area, PGME levels were below the detection limits. The elimination kinetics of PGME were also studied in three highly exposed persons, and mean excretion half-lives of PGME of approximately 4.4 h were found. On the basis of our results we made a rough calculation of a future biological tolerance value: we would except that concentrations of 38-109 mg per litre of blood and 10-31 mg per litre of urine would correspond to the German MAK value for PGME (375 mg/m3).

Adult↗
PubMed1992

Internal exposure to organic substances in a municipal waste incinerator.

Fifty-three persons occupied in a municipal waste incinerator were examined with respect to their internal exposure to organic substances which may be produced during pyrolysis of organic matter. For this purpose the levels of benzene in blood, polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in plasma, and mono- (MCPs), di- (DCPs), tri- (TCPs), tetra- (TCEPs) and pentachlorophenol (PCP) and hydroxypyrene in urine were determined. For control purposes, 431 men and women were examined. Significantly higher values for the workers were found for the excretion of hydroxypyrene [median (m): 0.24 vs 0.11 microgram/l; non-smokers], 2,4/2,5-DCP (m: 10.5 vs 3.9 micrograms/l) and 2,4,5-TCP (m: 1.2 vs 0.8 micrograms/l) and for the HCB level in plasma (m: 4.4 vs 2.8 micrograms/l). For the concentrations of 4-MCP and 2,3,4,6/2,3,5,6-TECP, the controls had significantly higher concentrations in urine than did the workers in the incineration plant (m: 4-MCP 1.7 vs 1.2; 2,3,4,6/2,3,5,6-TECP: 1.2 vs 0.3 micrograms/l). No significant differences between workers and controls were detected with respect to benzene in blood (m: 0.20 vs 0.28 microgram/l; non-smokers), 2,4,6-TCP and PCPs in urine (m: 0.85 vs 0.60 and 2.2 vs 2.2 micrograms/l) or the levels of PCB congeners in plasma (m: sigma 138, 153, 180: 5.6 vs 4.1 micrograms/l). The elevated levels of hydroxypyrene, 2,4/2,5-DCP, 2,4,5-TCP and HCB in biological material may be related to the incineration of the waste. These elevations, however, are very small and are of interest more from the environmental than from the occupational point of view.

Adult↗
PubMed1992

Investigations on health hazards of chimney sweeps in Germany: results of a follow-up study.

Within the framework of a longitudinal study, 127 chimney sweeps from the area of Upper and Middle Franconia (Bavaria, Germany), who had participated in a first medical check-up in 1974, were offered follow-up examinations in 1990. Eighty-one subjects participated in these examinations; in addition individual occupational case histories and medical case histories were obtained for a further 15 and 35 chimney sweeps, respectively. Five test subjects had died before the evaluation deadline (August 15, 1990). The causes of death were a non-Hodgkin's lymphoma, a bladder carcinoma, pulmonary metastases with unknown primary tumour, a suicide and an acute myocardial infarction. Conspicuous results were carcinoma of the oesophagus in one case and leucoplakia of the mucous membranes in the mouth and pharyngeal region in three cases; furthermore one chimney sweep had two haemorrhagic lumps on his vocal cords. Taking into account important non-occupational hazards (alcohol and nicotine abuse) as possible causes of these changes and the lack of relevant occupational exposure to products of incineration over a number of years, none of these cases nor any of the other ascertained results could be considered likely to be causally related to occupational activities. Due to the small number of cases, an epidemiological risk evaluation did not seem useful. Comparison with the results of other chimney sweep studies published in the international literature is not helpful due to the differences in study design, the varying case frequencies, and the different conditions of exposure.

Adult↗
PubMed1992

Biological monitoring in the occupational setting--relationship to cadmium exposure.

Statutory health surveillance of occupational exposure to cadmium exists in most Western countries. For biological monitoring, both indicators of internal dose and indicators of effect are available. Cadmium in urine is an indicator of chronic exposure and essentially reflects the body burden under low-exposure conditions and in the absence of renal damage. Whole blood cadmium is primarily a useful indicator for use in evaluations of recent exposures. Biological threshold limit values for cadmium in urine and blood are based on the correlation of biological levels with thresholds for renal dysfunction. The use of markers of high and low molecular weight proteinuria should be integrated into the health surveillance of cadmium-exposed workers. Priority should be given to the determination of albumin and of proteins such as beta 2-microglobulin, retinol-binding protein and alpha 1-microglobulin. Interpretation of biological monitoring data in terms of the threshold values requires a programme of periodic biological, medical and environmental monitoring.

Cadmium↗
PubMed1991

Internal and external quality control in the toxicological analysis of blood and urine samples in the Federal Republic of Germany.

Due to a technical rule for dangerous agents (TRGS 410), issued by the Ministry of Labor in the Federal Republic of Germany in 1979, toxicological analyses in biological materials must be carried out under conditions of "statistical quality control". This quality-control scheme provides internal and external control programmes. For internal quality control, the results of many years of experience with five commercially available control specimens and one "home-made" control have been evaluated. The control samples showed good, comparable results over a long period. Except in a few cases, there was good agreement between our results and the assigned values. Since 1982, the German Society of Occupational Medicine has offered eight intercomparison programmes for external quality. In samples from 80-90 laboratories, 6 metals in blood and around 20 inorganic and organic parameters in urine in 2 concentration adjustments have been analysed. Successful participation was certified if both results obtained for one parameter were within the tolerance range (assigned value +/- 3 SD). The average success rate was around 60%.

Blood Chemical Analysis↗
PubMed1990

Occupational chronic exposure to organic solvents. XIII. Glycolether exposure during the production of varnishes.

Seventeen persons (2 women and 15 men), who were exposed to glycolethers in a varnish production plant, were examined according to their external and internal solvent exposure. The workers in the production plant (n = 12) were exposed to average concentrations of ethoxyethanol, ethoxyethyl acetate, butoxyethanol, 1-methoxypropanol-2, 2-methoxypropyl-1-acetate and xylene of 2.8; 2.7; 1.1; 7.0; 2.8 and 1.7 ppm. In the air of the store (n = 3) and in the laboratory (n = 2) only minor concentrations of xylene respectively xylene and ethoxyethyl acetate could be measured. Internal exposure was estimated by measuring butoxyethanol (BE) in blood as well as ethoxyacetic acid (EAA) and butoxyacetic acid (BAA) in urine samples. Urine samples were taken pre- and post-shift. As expected, the highest values were found in the varnish production. The average post shift concentrations of BE, EAA and BAA were 121.3 micrograms/l; 167.8 and 10.5 mg/l. The relatively high concentrations of EAA and BAA in pre-shift samples can be explained by the long half-lives of these metabolites. According to our findings most of the glycolethers were taken up through the skin. Comparing our results with those reported in the literature we think that a future tolerable limit value for the concentration of ethoxyacetic acid in urine should be in the order of 100 to 200 mg/l.

Adult↗
PubMed1990

Occupational chronic exposure to metals. II. Nickel exposure of stainless steel welders--biological monitoring.

Stainless steel welders (n = 103) were examined. To estimate external exposure, personal air sampling was used. Internal exposure was quantified by the determination of nickel levels in erythrocytes, plasma and urine. Men and women (n = 123) were examined for control purposes. In the plasma and erythrocytes of the controls the nickel concentration was below the level of detection (less than 1.8 micrograms/l). The element concentrations in urine were between less than 0.1 and 13.3 micrograms/l. Of the controls 95% showed nickel levels in urine below 2.2 micrograms/l (reference value). The average concentration of nickel in the air was 93 +/- 81 micrograms/m3. The average concentration of nickel in the plasma samples was 4.9 +/- 4.0 micrograms/l (95th percentile 12.8 micrograms/l). In erythrocytes nickel could not be detected. The nickel concentrations in the urine of the welders were 18.5 +/- 28.5 micrograms/l on average (95th percentile 52.5 micrograms/l). Only a weak correlation between the nickel levels of plasma and urine could be detected (Curine = 2.07 + 8.45 Cplasma; r = 0.294; p less than 0.01). Based on our results and on the reported literature a future limit value for the nickel concentration in urine should lay between 30 and 50 micrograms/l. This value corresponds to an external exposure of 500 micrograms nickel per cubic metre.

Adult↗
PubMed1990

Significance of exposure to benzene and other toxic compounds through environmental tobacco smoke.

In order to assess the uptake of benzene from environmental tobacco smoke (ETS) and to estimate its contribution to the total body burden of benzene observed in non-smokers, two experimental studies have been conducted. Controlled exposure to high levels of ETS equivalent to 10 ppm CO for 9 h and 20 ppm for 8 h resulted in a nonsignificant increase in blood benzene levels and a significant increase in exhaled CO, COHb and cotinine in serum and urine. The slightly rising blood concentration of benzene following experimental ETS exposure was paralleled by an increased exhalation of benzene and aromatic hydrocarbons and in contrast to blood levels, this increase was significant. The blood levels of benzene obtained during exposure were comparable to those observed at the time of admission to the laboratory, when biomarkers of ETS uptake, e.g. cotinine in serum and urine, were at the limit of detection, thus demonstrating that these background levels were not from ETS exposure. No difference in the urinary excretion of phenol, the main metabolite of benzene, was found during the experimental periods. The background levels of urinary phenol in unexposed nonsmokers were rather high, demonstrating that phenol excreted in urine must be formed from several endogenous and exogenous precursors. In the light of our findings it is highly questionable whether exposure to benzene from ETS under real life conditions poses a cancerogenic risk to the general population, which is measurable today or in the future by toxicological or epidemiological methods.

Adult↗
PubMed1989

[Infection following surgery of the gastrointestinal tract in newborn infants].

In a retrospective study we examined the postoperative course of 642 children who had been operated on during the newborn period. 247 of them had been operated on for disorders of the gastrointestinal tract. 27.5% of these developed septicaemia: We showed that the frequency of sepsis could be reduced by perioperative antibiotic cover in all diseases with the exception of necrotising enterocolitis where antibiotic treatment was performed. Septicaemic courses were most frequent in premature infants and in those with necrotising enterocolitis. These results will be examined further in a subsequent prospective study.

Enterocolitis, Pseudomembranous↗
PubMed1989

[Complications after surgical interventions in the neonatal period and their relevance for quality of life].

In a retrospective study the postoperative course was examined of 296 neonates who had a birthweight of more than 1500 g and a congenital malformations between 1981 and 1987. A questionnaire was sent to the parents of the 242 surviving children in which they were asked about their children's current quality of life (average age 5.3 years). Of the 151 parents responding, 42% were of the opinion that the quality of their children's life had been reduced. The main reason was the operated malformation or accompanying illnesses. Only in 5% of the cases were postoperative complications considered responsible for the decline in quality of life.

Child↗