Biomedical subjects

J Angerer

Publications and source records attributed to J Angerer.

At least 73 records · Page 4Linked to original sources

PubMed1999

Influence of maternal age and duration of pregnancy on serum concentrations of polychlorinated biphenyls and hexachlorobenzene in full-term neonates.

Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) are ubiquitous carcinogenic and teratogenic compounds that are transplacentally transferred from mother to fetus during pregnancy. It was the aim of the present study to evaluate the possible influence of maternal age and duration of pregnancy on the neonatal burden with these substances. Blood samples were taken from 80 full-term German neonates within the first 12 h of life, before the first oral feeding. The serum concentrations of six PCB congeners (28, 52, 101, 138, 153, and 180) and HCB were determined with capillary gas chromatography with electron capture detection. The concentrations of the lower chlorinated PCB congeners (28, 52, and 101) were below the detection limit. PCB 153 showed the highest serum concentration (median 0.42 microg/l), followed by PCB 138 (0. 34 microg/l) and PCB 180 (0.17 microg/l). Total PCB concentration was 0.96 microg/l, HCB concentration 0.61 microg/l. All detectable PCB congeners and the total PCB concentration correlated significantly with the gestational age of the newborns (r = 0.2639; p < 0.01), with 50-140% higher serum levels in children born at 42 weeks of gestation as compared with neonates born in the 38th week. HCB concentration correlated with maternal age (r = 0.249; p < 0.01), with 2.7-fold higher serum levels in offspring of 40-year-old as compared with 20-year-old women. It is concluded that the neonatal burden with organochlorine compounds depends on maternal age and duration of pregnancy, thereby reflecting the increase in body pollution with these substances during human life as well as a continuous transplacental transfer from mother to fetus during pregnancy.

Birth Weight↗

PubMed1998

Biological monitoring of dinitrotoluene by gas chromatographic-mass spectrometric analysis of 2,4-dinitrobenzoic acid in human urine.

The method of analysis described permits the determination of 2,4-dinitrobenzoic acid down to the lower microg l(-1) range in the urine of persons exposed to dinitrotoluene. 2,4-Dinitrobenzoic acid is the main metabolite of 2,4-dinitrotoluene and technical dinitrotoluene. After acidic hydrolysis, which served to release the conjugated part of the 2,4-dinitrobenzoic acid, the analyte was selectively separated from the urine matrix via various extraction steps and then derivatised to the methyl ester. Quantitative analysis was carried out using capillary gas chromatography and mass selective detection. 3,5-Dinitrobenzoic acid was used as an internal standard. The detection limit was 1 microg l(-1) urine. The relative standard deviations of within-series imprecision were between 5 and 6%. The relative recoveries were between 91 and 110% depending on the concentration. The analytical method developed as part of this study was used to investigate a collective consisting of 82 urine samples from persons working in the area of explosives disposal. The concentrations of 2,4-dinitrobenzoic acid determined ranged from the detection limit to 95 microg l(-1) urine. The method allowed the quantification of low-level internal exposure to dinitrotoluene.

Carcinogens↗

PubMed1998

Analysis of nitroaromatic compounds in urine by gas chromatography-mass spectrometry for the biological monitoring of explosives.

Organic nitrocompounds are the most frequently used constituents of explosives and some of them have been evaluated to be highly toxic or even carcinogenic. Human contact with explosives may originate from a variety of sources, including occupational exposure during the production of ammunition as well as environmental exposure due to the contamination of soil and ground water reservoirs on former military production sites and training areas. This paper describes two gas chromatography-mass spectrometry-selected ion monitoring methods for the determination of twelve nitroaromatic compounds in urine (nitrobenzene, 1,2-dinitrobenzene, 1,3-dinitrobenzene, 1,3,5-trinitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2,4,6-trinitrotoluene, 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene). The analytes are detectable in the lowest microg/l range, with imprecisions of 3-22% within series and 5-29% between series, depending on the compound of interest. Both procedures are rapid and relatively easy to perform and, therefore, are advantageous for the screening of occupationally or environmentally exposed persons. We analysed urine samples obtained from nine workers from an ammunition dismantling workshop and from twelve control persons. 2,4,6-Trinitrotoluene was detected in six samples at concentrations between 4 and 43 microg/l. The main metabolites of 2,4,6-trinitrotoluene, 4-amino-2,6-dinitrotoluene and 2-amino-4,6-dinitrotoluene, were found in a concentration range from 143 to 16,832 microg/l and from 24 to 5787 microg/l, respectively. Nonconjugated aminodinitrotoluenes were present as varying percentages of the total amount. 2,4-Dinitrotoluene and 2,6-dinitrotoluene were found in two samples (2-9 microg/l). Nitroaromatics were not detectable in urine specimens from control persons.

Aniline Compounds↗

PubMed1998

S-p-toluylmercapturic acid in the urine of workers exposed to toluene: a new biomarker for toluene exposure.

A mercapturic acid attached to the aromatic ring of toluene was for the first time detected in human urine as a metabolite of toluene. Since the metabolism of toluene is usually considered to take place at the side-chain, this gives, besides the biosynthesis of cresols, a further hint of a metabolic conversion of the aromatic system. We examined a group of 33 workers occupationally exposed to toluene, determining the concentrations of toluene in ambient air and in whole blood, o-cresol and hippuric acid in urine and p-toluylmercapturic acid (p-TMA) in urine. All blood and urine samples were collected post-shift. The renal excretion of S-p-toluylmercapturic acid showed highly significant correlations with established parameters of a biological monitoring of toluene. The median ambient air concentration was 63 ppm, ranging from 13 to 151 ppm, the median concentration of toluene in whole blood was 804 microg/l, corresponding to median urinary concentrations for o-cresol of 2.3 mg/l, hippuric acid of 2.3 g/l and p-TMA of 20.4 microg/l. p-TMA was not detectable in urine samples of a control group of 10 non-exposed persons. Both the German Biological Tolerance Values (BAT-values) for toluene in blood (1000 microg/l) and o-cresol in urine (3 mg/l) correspond to a mean p-TMA elimination of approximately 50 microg/l, and thus are in agreement with each other. According to our results p-TMA reflects internal toluene exposure diagnostically sensitive and specifical. With the developed analytical procedure we determined a median benzylmercapturic acid (BMA) concentration of 190 microg/l in the urine samples of the toluene exposed persons. We also determined a median BMA concentration of 30 microg/l in the control samples of non-exposed persons. However, these results are preliminary and require further confirmation as the reliability of the method was determined only for p-TMA.

Acetylcysteine↗

PubMed1998

N-methylcarbamoyl adducts at the N-terminal valine of globin in workers exposed to N,N-dimethylformamide.

N,N-dimethylformamide (DMF) is a commonly used industrial solvent. The formation of some metabolites of DMF in humans occurs via N-methyl-carbamoylated species (e.g. N-methylcarbamoylated glutathione). The aim of our study was to investigate whether DMF leads to N-methylcarbamoylated adducts at the N-terminal valine of haemoglobin (Hb). Therefore, Hb adduct levels of ten DMF exposed workers and ten controls were analysed by a specific and sensitive detection method using capillary gas chromatography and a mass selective detector (GC/MS). Using this method we were able to show for the first time that Hb adducts are formed during the metabolism of DMF in humans. The general population, however, shows still unidentified background levels of this adduct which are on average lower by a factor of 50. The pathway for the formation of the investigated DMF-Hb adduct in workers exposed to DMF is still unknown. As identical adducts were also found after exposure to methylisocyanate (MIC), our work indicates the formation of MIC during the metabolism of DMF. The formation of Hb adducts with DMF and its relevance for occupational health is a subject of further research.

Acetylcysteine↗

PubMed1998

Ambient and biochemical effect monitoring of workers exposed to ethylene oxide.

OBJECTIVES: Ethylene oxide is an alkylating agent known to be a directly acting mutagen and carcinogen. This study describes the relationship between workplace ambient air concentrations of ethylene oxide and the concentration of N-2-hydroxyethylvaline in the globin of exposed workers. METHODS: During the sterilization of medical equipment, 12 workers were occupationally exposed to ethylene oxide. Personal and stationary ambient air measurements were carried out to monitor the external exposure. The determination of the protein adducts was based on the N-alkyl-Edman method, introducing a new commercially available dipeptide standard for calibration purposes. RESULTS: Ethylene oxide concentrations ranging from 0.2 to 8.5 ppm were found in the workplace air. The adduct concentrations ranged from 5,219 to 32,738 pmol N-2-hydroxyethylvaline/g globin in the case of regularly exposed workers (n = 9) and from 518 to 3,321 pmol N-2-hydroxyethylvaline/g globin for three persons with occasional contact with ethylene oxide. CONCLUSIONS: The Deutsche Forschungsgemeinschaft established in 1993 a relationship between the ethylene oxide concentration in ambient air and the amount of N-2-hydroxyethylvaline in human globin. By extrapolation, constant exposure to 1 ppm ethylene oxide should yield approximately 4,000 pmol N-2-hydroxyethylvaline/g globin. The ambient air concentrations of ethylene oxide and the amount of N-2-hydroxyethylvaline determined within the present study confirm this extrapolation in practice. In addition, the determination of adducts based on the use of commercially available dipeptide standards for calibration purposes turned out to be an advantageous alternative to the commonly used protein standards.

Air Pollution, Indoor↗

PubMed1998

N,N-dimethylformamide--influence of working conditions and skin penetration on the internal exposure of workers in synthetic textile production.

OBJECTIVES: This study examined the external and internal exposure to the solvent N,N-dimethylformamide (DMF) of 126 workers from a factory producing synthetic fibers. METHODS: Air measurements were carried out using personal air samplers with diffusion tubes (Drager, ORSA 5). For the purpose of biological monitoring the levels of N-methylformamide (NMF) in urine were measured in preshift and postshift samples. Determinations were carried out using gas chromatography. Anamnestic data were collected with standardized questionnaires, including personal data, working history and current working conditions, and former and current illness with regard to the effects of DMF. Skin diseases were documented by a dermatologist. RESULTS: DMF concentrations measured in the air ranged between <0.1 and 37.9 ppm (median 1.2 ppm). Concentrations of NMF varied from 0.05 to 22.0 mg/l (preshift values) and from 0.9 to 100.0 mg/l (postshift values). The creatinine-related values (0.02-44.6 mg/g preshift; 0.4-62.3 postshift) were subject to less variation and therefore represented the level of exposure better than the values related to volume. Additional investigation of a subcollective (n=31) over a period of 4 days showed that NMF did not accumulate in the organism. The positive but relatively weak association observed between the DMF concentrations measured in the workplace air and the values recorded for internal exposure in this study can be explained by influencing factors such as dermal absorption or protective clothing. Interindividual differences in internal exposure were found for the specific work areas. The German BAT value (15 mg NMF/l urine) was exceeded in 36 persons (29%) despite the use of breathing protection and protective gloves, without increased values being measured in the air. Increased absorption without higher-level exposure could particularly also be observed in employees with eczema. CONCLUSIONS: From the point of view of the prevention of disease, biological monitoring is the best instrument for exposure assessment of workers exposed to DMF.

Adult↗

PubMed1998

Ethylene oxide-protein adduct formation in humans: influence of glutathione-S-transferase polymorphisms.

OBJECTIVE: The influence of the polymorphic human glutathione-S-transferase (GST) T1 and M1 genotypes (classified as "conjugators" and "nonconjugators") on the biological effects of nonoccupational ethylene oxide exposure as reflected by the formation of globin N2-hydroxyethylvaline adducts was investigated. Specific attention was paid to smoking as a potential source of exposure. A total of 27 Caucasian subjects, including 10 women and 17 men, participated in the study. Volunteers were grouped as smokers, i.e., 6 subjects (5 male, 1 female), and nonsmokers, i.e., 21 subjects (12 male, 9 female). The regular cigarette consumption in the smoker group ranged from 10 to 25 cigarettes/day. METHODS: The amount of N2-hydroxyethylvaline (HEV) bound to the N-terminal valine in human globin was determined following a procedure described by Bader and co-workers and the Deutsche Forschungsgemeinschaft. The GST genotypes were determined by a polymerase chain reaction (PCR) analysis outlined by Bell and colleagues (with beta-globin serving as an internal standard) and Kempkes and co-workers (coamplification of the GSTT1 fragment). RESULTS: The median level of HEV detected in the smoker group was 280 pmol/g globin as compared with the median value of 50 pmol/g globin recorded for the nonsmokers, indicating that ethylene oxide intake from cigarettes may result in a approximately 5-fold higher overall HEV level in smokers in comparison with nonsmoking individuals. No dose-effect correlation was observed between daily cigarette consumption and the resulting HEV levels. Moreover, the individual GSTT1 or GSTM1 genotype did not influence the HEV level in smokers. The subgroup of nonsmoking GSTT1 conjugators revealed a median HEV value of 46 pmol/g globin as compared with the median value of 92 pmol/g globin found in the nonconjugator subgroup. Subjects with the GSTM1 gene had a median HEV value of 55 pmol/g globin, whereas subjects with the gene deletion had a median HEV value of 44 pmol/g globin. The 2-fold increase in the median HEV value detected in GSTT1 non-conjugators as compared with GSTTI conjugators indicates an influence of GSTT1 on the globin HEV levels. This hypothesis was found to be significant in the nonparametric Mann-Whitney U-test for independent samples (P < 0.002, two-sided). The same test was applied to evaluate the influence of GSTM1 on the globin HEV levels. No significant influence was observed (P > 0.10; two-sided). CONCLUSIONS: This result is in accordance with the finding that ethylene oxide is a substrate for GSTT1 but not for GSTM1. In addition, this study demonstrates a clear influence of genetically determined GSTT1 status on biological effects, e.g., protein adduct formation after non-occupational ethylene oxide exposure. In smokers, however, a modulating influence of GSTT1 status was not observed.

Case-Control Studies↗

PubMed1998

Musk xylene: analysis, occurrence, kinetics, and toxicology.

1,3-Dimethyl-2,4,6-trinitro-5-tert.-butylbenzene (musk xylene, MX), a synthetic musk, is often used in fragrances and soaps to substitute the natural musk. MX belongs to the common group of nitromusk compounds. The main environmental intake of MX occurs after sewage introduction. The consumption of fish and drinking water as well as the use of body care and perfumed household products could lead to an ingestion of this substance in humans. Although the acute oral and dermal toxicity of MX is low, some hint for the carcinogenic potential of MX was found in one animal experiment. These findings and the high potential of MX as environmental contaminant, it is stable against biological and chemical degradation and it is highly lipophil, raised considerable attention in the field of environmental medicine. Biological monitoring and the toxicology of MX, which previously has been described to occur in human milk, human fat tissue, as well as human blood samples, are of central interest. The aim of this article is to summarize the data on the analysis, occurrence, kinetics, and toxicology of MX. As there is a lack of knowledge on human toxicity and human carcinogenicity of MX, a final evaluation of the toxicological data with regard to public health is still impossible. Nevertheless, in view of the published data about MX, there is no evidence for any substantial human risk at the moment.

Animals↗

PubMed1997

Determination of metabolites of pyrethroids in human urine using solid-phase extraction and gas chromatography-mass spectrometry.

The described method permits the determination of the five most important metabolites of the pyrethroids permethrin, cypermethrin, deltamethrin, lambda-cyhalothrin, fenvalerate, phenothrin and beta-cyfluthrin in human urine in one run. The major urinary metabolites of these substances are cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Cl2CA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (trans-Cl2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (Br2CA), fluoro-3-phenoxybenzoic acid (F-PBA) and 3-phenoxybenzoic acid (3-PBA). After acidic hydrolysis to release the conjugated carboxylic acid metabolites, the analytes were separated from the matrix by means of solid-phase extraction using a reversed-phase column. The components of the eluate were converted to their methyl esters and extracted in hexane. Separation and quantitative analysis of the pyrethroid metabolites was carried out by capillary gas chromatography and mass selective detection. 2-Phenoxybenzoic acid served as an internal standard. The detection limits lay between 0.3 and 0.5 microg per litre urine. The relative standard deviations of the within-series imprecision were between 1% and 6%. The relative recovery rates ranged between 90% and 98%. Using this method we determined the elimination of pyrethroid metabolites in 24-h urine samples from eight pest controllers after indoor application of permethrin. The detected concentrations ranged from 1 to 70 microg g(-1) creatinine.

Air Pollutants, Occupational↗

PubMed1997

Gas chromatographic method using electron-capture detection for the determination of musk xylene in human blood samples. Biological monitoring of the general population.

Musk xylene (2,4,6-trinitro-1,3-dimethyl-5-tert.-butylbenzene, MX), a synthetic musk often used in different fragrances and soaps to substitute the natural musk, is a potential contaminant of humans. In this publication, a specific and sensitive detection method for the determination of musk xylene in human blood samples is described. The clean-up of the blood samples includes an extraction step followed by a solid-phase adsorption to separate MX from other plasma components. Separation and detection was carried out by capillary gas chromatography and an electron capture detector (GC-ECD). The results were verified using qualitative capillary gas chromatography and a mass selective detector with electron impact ionisation (GC-EI-MS). epsilon-Hexachlorocyclohexane (epsilon-HCH) is used as internal standard. The reliability of the GC-ECD method has been proved. The relative standard deviations of the within-series imprecision were 12.7% for samples with a concentration of 0.5 microg/l and 2.1% for samples with a concentration of 5.0 microg/l, whereas the relative standard deviations for the between-day imprecision were 14.9% (0.5 microg/l samples) and 3.4% (5.0 microg/l samples). The losses during sample treatment were between 10.1% and 17.8%. No interfering peaks were observed. The absolute detection limit was 0.1 microg/l plasma. A total of 72 human blood samples were analysed to determine the MX concentrations within the general population. In 66 of the 72 human blood samples, the MX concentrations ranged from 0.10 to 1.12 microg/l plasma for the described method. In six samples no MX was detected. The median concentration was 0.24+/-0.23 microg MX/l plasma. The 95 percentile was 0.79 microg/l. No correlation could be found between MX concentrations and smoking habit, broca index, age, sex as well as fish consumption habits. Nevertheless, the results demonstrate the exposure of the general population to MX.

Chromatography, Gas↗

PubMed1997

Occupational chronic exposure to organic solvents. XVI. Ambient and biological monitoring of workers exposed to toluene.

OBJECT: Ambient air and biological monitoring of an occupational toluene exposure was carried out on a group of 33 workers. METHOD: The biological monitoring of the workers was based on determination of the concentration of toluene in blood and on quantification of the urinary metabolites o-cresol and hippuric acid. All blood and urine samples were collected post-shift. RESULTS: The average toluene concentration in the workplace air was 65 ppm, ranging from 13 to 151 ppm. AN average concentration of toluene in the blood of 911 microns/1 was found, corresponding to an average urinary concentration of 2.9 mg/1 (2.3 mg/g creatinine) o-cresol and 2.4 g/l (1.9 g/g creatinine) hippuric acid. Both urinary metabolites can be correlated with the concentration of toluene in ambient air and blood, respectively. CONCLUSIONS: The results of our study indicate that the determination of the urinary o-cresol excretion represents a diagnostically specific and sensitive parameter for the estimation of an individual toluene uptake. In contrast, monitoring of the concentration of hippuric acid in urine cannot be recommended for assessment of individual exposure. To set up a biological tolerance value (BAT) for o-cresol, a urinary concentration of 3 mg/l o-cresol should be in accordance with the current MAK value of 50 ppm toluene.

Air Pollutants, Occupational↗

PubMed1997

The determination of metals (antimony, bismuth, lead, cadmium, mercury, palladium, platinum, tellurium, thallium, tin and tungsten) in urine samples by inductively coupled plasma-mass spectrometry.

OBJECTIVE: An analytical method has been established to determine the concentration of antimony (Sb), bismuth (Bi), lead (Pb), cadmium (Cd), mercury (Hg), Palladium (Pd), platinum (Pt), tellurium (Te), tin (Sn), thallium (Tl) and tungsten (W) in urine. The aim was to develop a method which is equally suitable for the determination of environmentally as well as occupationally caused metal excretion. METHODS: Inductively coupled plasma-mass spectroscopy (ICP-MS) was used for the determination of metals. Calibration was done using aqueous solutions and standard addition respectively. RESULTS: Urine samples of 14 persons occupationally non-exposed to metals were analysed. With the exception of Pt and Bi all the metals were found in these urine samples. The detection limits for these metals lie between 5 and 50 ng/l. CONCLUSIONS: For some metals, which are important from an occupational as well as an environmental viewpoint, ICP-MS is more sensitive than atomic absorption spectrometry (AAS). ICP-MS, moreover, is welcome as a reference method for AAS with the additional advantage of multi-element measurement.

Adult↗

PubMed1997

Occupational exposure to polycyclic aromatic hydrocarbons in a graphite-electrode producing plant: biological monitoring of 1-hydroxypyrene and monohydroxylated metabolites of phenanthrene.

OBJECTIVE: The objective of this study was to assess external and internal exposure to polycyclic aromatic hydrocarbons (PAHs) of workers who are employed in a graphite-electrode producing plant. Additionally we wanted to contribute to the question of biological limit values in order to reduce exposure to tolerable levels. METHODS: At five different working places 12 stationary and 16 personal air measurements were carried out to determine the concentrations of phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[a]pyrene and dibenz[a, h]anthracene in air. In addition, we investigated the excretion of 1-, 2 + 9-, 3- and 4-hydroxyphenanthrene and of 1-hydroxypyrene in the urine of 67 workers by a very sensitive and practical high-performance liquid chromatographic (HPLC) method with fluorescence detection; 2- and 9-hydroxyphenanthrene could not be separated with our analytical method. RESULTS: During the production of graphite electrodes significantly higher PAH exposures were found in the baking and impregnation area than in the crushing, graphitisation and conditioning area. The results of personal air measurements (mean values of the sum of eight PAHs) are: 29.3 (baking), 23.4 (impregnation), 5.2 (crushing), 1.3 (graphitisation) and 0.4 microgram/m3 (conditioning). Stationary air measurements yielded similar concentrations. Workers employed in the baking and impregnation areas excreted the highest amount of PAH metabolites in urine. The 1-hydroxypyrene concentrations (median) were: 23.4 (baking), 22.0 (impregnation), 9.6 (crushing), 1.8 (graphitisation) and 2.3 micrograms/g creatinine (conditioning). The corresponding concentrations of the sum of monohydroxylated phenanthrene metabolites (median) were: 23.1, 36.0, 10.4, 4.6 and 7.6 micrograms/g creatinine. Within the monohydroxylated phenanthrene metabolites 3-hydroxyphenanthrene predominates with a percentage of 43%. Our results showed that a benzo[a]pyrene concentration in air of 2 micrograms/m3 would lead to 1-hydroxypyrene concentrations in urine of 20-74 micrograms/g creatinine. That means that corresponding values in the literature which lie between 4.4 and 6.2 micrograms/g creatinine are due to other conditions of exposure and cannot be applied to graphite-electrode producing plants. CONCLUSIONS: Although to date there are no obligatory biological exposure limits for metabolites of PAHs in urine, it must be concluded that the internal PAH exposure is too high at some work places in this plant, as is generally the case in graphite-electrode producing plants. This is probably caused by skin absorption of PAHs. So for the prevention of health hazards by PAH, internal exposure must be measured using biological monitoring. Although it has not been possible to establish biological exposure limits for PAHs until now, we suggest a reduction in skin contact with these substances and thereafter use of the 90th percentile of the results of biological monitoring as "action levels" for corrective measures.

Air↗

PubMed1997

Neurotoxicity of long-term low-level exposure to carbon disulphide: results of questionnaire, clinical neurological examination and neuropsychological testing.

OBJECTIVE: Carbon disulphide (CS2) is highly neurotoxic. There is ample evidence of damage to the peripheral and central nervous system. The air concentration at which such adverse effects can first be observed is presently a subject of controversy. METHODS: In a cross-sectional study of CS2-exposed workers from the viscose industry and healthy controls, data on neurological complaints, basic laboratory diagnosis, clinical neurological examination and neuropsychological testing were evaluated. Data were from 222 workers in the viscose industry exposed to CS2 and 191 employees from the same factory with similar physical and psychological stress factors but without occupational contact with neurotoxic substances. Multiple linear or multiple logistic regression analysis was used to check for statistical differences. RESULTS: The median of the CS2-measurements using personal air sampling was below the current maximum concentration permissible (MAK value) in Germany (10 ppm) in all departments. The threshold limit value was, however, exceeded in almost 10% of the persons investigated. Exposure fluctuated between < 0.2 and 65.7 ppm (median of all departments was 4.02 ppm). As a parameter of internal exposure, CS2-metabolite 2-thio-1,3-thiazolidine-4-carboxylic acid (TTCA) concentrations in the urine of the exposed persons were between < 0.16 and 10.9 mg/g creatinine (median 1.43 mg/g). CONCLUSIONS: Neither an increase in subjective complaints nor an increase in pathological findings in clinical-neurological and neuropsychological examination could be found in persons exposed to CS2 at the exposure levels described.

Adult↗

PubMed1997

Internal exposure to hazardous substances of persons from various continents: investigations on exposure to different organochlorine compounds.

UNLABELLED: The aim of the study was to investigate the concentration of organochlorine compounds of environmental-medical relevance in biological materials from refugees with regard to their countries of origin and to compare these concentrations with the internal exposure of the German general population. METHODS: During medical examination after entry to Germany specimens could be taken from the refugees to determine the following parameters of biological monitoring: 1,1-dichloro-2,2-bis(-chlorophenyl)-ethylene (DDE-P), polychlorinated biphenyls (PCB-P), pentachlorophenol (PCP-P) and the beta- and gamma-hexachlorocyclohexanes (beta-HCH-P, gamma-HCH-P) in plasma and the excretion of chlorophenols (4-MCP-U, 2,4-DCP-U, 2,5-DCP-U, 2,4,5-TCP-U, 2,4,6-TCP-U, 2,3,4,5-TeCP-U, 2,3,5,6-TeCP-U) in urine. One hundred and three men (13 from former Yugoslavia, 29 from the former USSR, 33 Africans and 28 Asians) ranging from 16 to 53 years of age (median 27 years) were investigated. Thirty four male Germans without occupational exposure to these substances and a similar age structure (age 25-36 years; median 26 years) served as a control group. RESULTS: A much higher level of internal exposure was found for the DDT metabolite, DDE, for those persons from Asia, the former USSR and Africa compared with the German controls (medians: 16.9 micrograms/l, 11.9 micrograms/l and 10.9 micrograms/l) and 1.1 micrograms/l). The levels of PCB in plasma were below the detection limit in the majority of refugees. In the control group, however, the PCB levels were higher (sigma PCB; median: 2.1 micrograms/l, maximum: 13.3 micrograms/l). The highest beta-HCH concentrations, up to a maximum of 15.5 micrograms/l, were detected in the persons from the former USSR and Asia. The five groups do not differ with regard to internal exposure to PCP and gamma-HCH. Renal excretion of 4-MCP, 2,4-DCP and TeCP did not differ between the five groups. The concentrations of 2,5-DCP in urine, however, were significantly lower in the Germans than the refugees from the four regions investigated. The median for the Germans was 3.0 micrograms/l and for the refugees between 10.8 and 14.7 micrograms/l. Also the levels of 2,4,5-TCP and 2,4,6-TCP in urine were lower in the German controls than in the men from the former USSR, Africa and Asia. CONCLUSIONS: Organochlorine compounds exist worldwide due to their extensive use. There are, however, regional differences for the various substance groups, which during biological monitoring are seen in the different background exposures of the general population. Particularly characteristic are markedly higher levels of DDE in plasma from the refugees compared with the German population.

Adolescent↗

PubMed1997

Electrophysiological investigation of central, peripheral and autonomic nerve function in workers with long-term low-level exposure to carbon disulphide in the viscose industry.

OBJECTIVE: Neurotoxicity of carbon disulphide (CS2) is well known. The air concentration at the workplace at which such adverse effects can first be observed is the subject of controversial discussion. METHODS: In a cross-sectional study on CS2-exposed workers peripheral motor and sensory nerve conduction studies, somatosensory evoked potentials, thermotesting and investigation of forced respiration sinus arrythmia have been carried out. The data from 222 workers exposed to CS2 in the viscose industry were evaluated and compared with data from 191 employees from the same factory with similar physical and psychological stress factors but without detectable occupational contact to neurotoxic substances. Median exposure to CS2 was below the currently valid occupational-medical threshold limit value (MAK-value) of 10 ppm. Multiple linear or multiple logistic regression analysis was used to check for statistical differences. RESULTS: Binary evaluation (comparison of exposed persons versus controls after multiple linear regression) revealed a slightly lower value in the exposed group for the motor nerve conduction velocity (MNCV, -0.76 m/s, median 48 m/s), but a long way from pathological thresholds. No dose-response relationship could be found within the exposed group for any evaluation criteria of CS2-exposure. Somatosensory evoked potentials, thermotesting and analysis of heart rate variability yielded no indication of a neurotoxic effect of CS2. CONCLUSION: Isolated decrease of MNCV in binary evaluation is, with regard to the known mechanism of CS2-neurotoxicity and the lack of a dose-response relationship, obviously not due to toxic effects. We interpret our results as showing that an adverse effect of carbon disulphide at the exposure ranges found was not detectable in the exposed group.

Adult↗

PubMed1997

Biological monitoring and biochemical effect monitoring of exposure to polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous carcinogenic substances to which man is exposed in the environment and at certain workplaces. Estimation of the resulting health risk is therefore of great occupational-medical and environmental-medical importance. Determination of the DNA and protein adducts of PAHs is the most suitable way of estimating this risk. The analytical methods used thus far, above all, 32P postlabeling, immunoassays, and synchronous fluorescence spectroscopy, are, however, too nonspecific; therefore, the results lack accuracy and are not comparable with one another. Only the use of very specific methods of instrumental analysis [above all, high-performance liquid chromatography (HPLC) and gas chromatography/ mass spectrometry (GC/MS)] can counteract this deficit. However, these methods can successfully be used mainly to determine the protein adducts of PAHs. Hemoglobin adducts, for example, do not have repair mechanisms like DNA adducts. They therefore occur in higher concentrations and can thus be analytically detected more easily. At present, mainly the monohydroxylated metabolites of PAHs are being determined in urine with great success. Using specific enrichment methods and HPLC with fluorescence detection it is even possible today to determine the internal PAH exposure of the general population. The detection limits lie in the lower nanogram-per-liter range. In view of the importance of this group of substances, determination of PAH adducts and the detection of their metabolites in urine will remain at the center of future occupational-medical and environmental-medical/toxicological research. In general, the lack of reference substances must be lamented.

Benzo(a)pyrene↗