Quantitative determination of amphetamines, cocaine, and opiates in human hair by gas chromatography/mass spectrometry.

Hair of young subjects (N = 36) suspected for drug abuse was analysed for morphine, codeine, heroin, 6-acetylmorphine, cocaine, methadone, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethylamphetamine (MDEA). The analysis of morphine, codeine, heroin, 6-acetylmorphine, cocaine, and methadone in hair included incubation in methanol, solid-phase extraction, derivatisation by the mixture of propionic acid anhydride and pyridine, and gas chromatography/mass spectrometry (GC/MS). For amphetamine, methamphetamine, MDA, MDMA, and MDEA analysis, hair samples were incubated in 1M sodium hydroxide, extracted with ethyl acetate, derivatised with heptafluorobutyric acid anhydride (HFBA), and assayed by GC/MS. The methods were reproducible (R.S.D. = 5.0-16.1%), accurate (85.1-100.6%), and sensitive (LoD = 0.05-0.30ng/mg). The applied methods confirmed consumption of heroin in 18 subjects based on positive 6-acetylmorphine. Among these 18 heroin consumers, methadone was found in four, MDMA in two, and cocaine in two subjects. Cocaine only was present in two, methadone only in two, methamphetamine only in two, and MDMA only in seven of the 36 subjects. In two out of nine coloured and bleached hair samples, no drug was found. Despite the small number of subjects, this study has been able to indicate the trend in drug abuse among young people in Croatia.

Assessment of occupational exposure to organic solvents in paint industry.

The paper brings the preliminary results of ambient and biological monitoring of exposure to xylene, toluene, and styrene in paint industry. Air samples were collected at seven stationary locations at work places of 31 male workers. Samples of venous blood were taken from all workers for styrene, toluene, and xylene analysis, and of urine for metabolic derivatives, mandelic, phenylglyoxylic, and o- and m-methylhippuric acids analysis. Blood was collected on Wednesday before and after work, and urine on Monday, Wednesday and Thursday before work and on Wednesday after work. Workers were exposed to moderate concentrations of xylene and low concentrations of toluene and styrene. During periodic medical surveillance Questionnaire 16 was applied as a screening test for early central nervous disturbances. Seven workers had positive findings and required further psychological tests as recommended by WHO. Risk assessment of combined long-term exposure to organic solvents in occupational environment requires a prospective epidemiological study with matched control group.

Analysis of drugs of abuse in urine by gas chromatography/mass spectrometry: experience and application.

This paper describes quantitative methods for determination of urinary drugs/metabolites. The analysis included indicators of opiate (morphine, codeine, 6-monoacetylmorphine) and methadone (methadone) consumption, indicator of marihuana/hashish consumption (11-nor-9-tetrahydrocannabinol-9-carboxylic acid), indicators of cocaine consumption (cocaine, benzoylecgonine, and ecgonine methyl ester) and of amphetamines consumption (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, and 3,4-methylenedioxyethylamphetamine). The methods included solid-phase extraction of urine, concentration of eluent, derivatisation, and quantitative analysis by gas chromatography/mass spectrometry (GC/MS) on a capillary column in the electron impact and selected ion monitoring (SIM) mode. Sensitivity, reproducibility, and accuracy were determined for all analytes (limit of detection between 3 and 12 ng/ml, precision < 10%, accuracy > 92%). The accuracy was checked through analysis of standard reference materials and participation in an international quality assessment programme. The methods were used in the analysis of spot urine samples of 60 subjects suspected of drug abuse. Negative findings indicated several disadvantages of urine as a biological sample.

Red blood cell glycerol lysis and hematologic effects in occupational benzene exposure.

Forty-nine female workers in the shoemaking industry, exposed to a solvent mixture containing benzene and twenty-seven non-exposed controls, were investigated. Concentrations of benzene and toluene in the working atmosphere, as well as benzene and toluene in blood and phenols in pre- and post-shift urine as parameters of biological monitoring, were determined. In order to assess hematotoxic risk, a complete blood cell count with differential, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, reticulocytes, serum iron, alkaline phosphatase in neutrophils and red blood cell glycerol lysis time were determined in all subjects. Benzene concentrations in the workplace atmosphere at the shoemaking factory ranged from 1.9 to 14.8 ppm (median = 5.9). Significant difference in benzene in blood (p = 0.005) and phenol in post-shift urine (p = 0.003) between exposed workers and controls confirmed exposure to benzene. Hemoglobin level (p = 0.02) and mean corpuscular hemoglobin concentration (p = 0.0002) in the shoe workers were lower, and band neutrophils (p = 0.005) and mean corpuscular volume (p = 0.03) higher, than in controls. Red blood cell glycerol lysis time was significantly higher (p = 0.000001) in shoe workers (X +/- SD = 41.6 +/- 8.9) than in controls (X +/- SD = 31.1 +/- 6.5) and showed a significant correlation with exposure biomarkers. The results confirm that benzene exposure below 15 ppm may produce qualitative abnormalities, particularly macroerythrocytosis and increased red cell glycerol resistance, in the absence of an overt quantitative decrease in circulating blood cells. Increased resistance to the hemolytic action of glycerol is a potentially useful biological monitoring procedure in medical surveillance of benzene exposed workers. The results of this study suggest that potential threshold concentration for hematologic effects of benzene is lower than 15 ppm.

Genotoxic effects in workers exposed to benzene: with special reference to exposure biomarkers and confounding factors.

The aim of the study was to establish a correlation between biomarkers of exposure and cytogenetic test results in workers occupationally exposed to benzene and toluene, with special reference to confounding factors influencing the outcome of the cytogenetic test. The incidence of structural chromosome aberrations and sister chromatid exchanges was studied in the peripheral blood lymphocytes cell genome of 49 female shoe-makers, mean age 38 years, mean length of occupational exposure 17 years and in a group of 27 well-matched controls. Workers were exposed to concentrations of benzene up to 15 ppm and of toluene up to 50 ppm. The presence of benzene and toluene in the workers' blood samples, and the presence of phenol in pre- and post-shift urine were considered proof of occupational exposure. Chromosomal aberration analysis revealed a significant increase in dicentric incidence in the exposed group compared to the controls (P = 0.004). However, significant correlation between cytogenetic test results and the exposure biomarkers was not established. On the contrary, correlation between the cytogenetic test results and data on confounding factors (e.g. age and alcohol consumption), was marked. The major point raised by this study is the influence of confounding factors on the cytogenetic test outcome. This imposes the need for caution in the interpretation of cytogenetic test results, and ultimately in the estimation of individual genotoxicity risk related to low level benzene exposure.

Cognitive evoked potentials VEP P300 persons occupationally exposed to low concentrations of toluene.

Cognitive evoked potentials VEP P300 were examined in 49 workers at printing press occupationally exposed to low concentrations of toluene for averagely 20 years, and in 59 control subjects. The exposure level of toluene was evaluated in randomly selected subgroups comprising 36 exposed and 27 control subjects. The concentrations of toluene were measured in peripheral blood on Wednesday morning before entering the work area, while the hippuric acid in urine was measured before and after entering the work area. The results show that the absolute number of exposed subjects displaying lower amplitude of cognitive wave VEP P300R and prolonged latency of the accompanying spontaneous wave VEP P300F was significantly greater than that of the controls.

Brainstem auditory evoked potentials in individuals exposed to long-term low concentrations of toluene.

Brainstem auditory evoked potentials (BAEPs) were examined in 49 workers employed in a printing press, who were occupationally exposed to low concentrations of toluene for an average of 20.3 years, and in 59 subjects in a control group. In the group of exposed workers, a significant decrease was found in all wave amplitudes examined, a significant prolongation of P1 wave latency, and an increased interval of interpeak latencies (P3-P5), indicating that the extramedullary and high medullary part of the auditory pathway are biologically most frequently affected by chronic exposure to low concentrations of toluene. The level of exposure to toluene in both groups was evaluated by defining the concentration of toluene in peripheral blood and the concentration of hippuric acid and ortho-cresol in urine.

Biomarkers of exposure to organic solvents from glues used in table tennis bats.

In nine samples of the glues used to glue rubber onto the table tennis bats, benzene, toluene, xylene, trichloroethene (TRI) and tetrachloroethene (TETRA) were determined by head-space gas chromatography. The analyses demonstrated the presence of benzene (1.8-4.8% (w/w)), toluene (0.32-33.90% (w/w)) and TRI (0.0006-0.280% (w/w)) in seven samples and of toluene only (22.50-67.20% (w/w)) in two samples. Xylene and TETRA were not detected in any of the glue samples analysed. Benzene, toluene and TRI in blood, as a measure of body burden, were determined in four table tennis players (aged 11-14 years) and five volunteers (aged 26-38 years). They were at the same level as in the general population. The aim of the study was to draw attention to the possibility of exposure to organic solvents from glues used in table tennis bats, particularly as it is very often a question of child exposure.

Possible genotoxicity in low level benzene exposure.

Structural chromosome aberrations and sister chromatid exchanges (SCEs) in peripheral blood were studied in female workers employed in the shoe-making industry in two periods: 1987 (group I; N = 38) and 1992 (group II; N = 45). Only 11 of the workers were present in both groups and their results are presented both together and separately. Occupational exposure to benzene and toluene was confirmed through their determination in the working area, blood, and phenol in pre- and post-shift urine. The results were compared with those from the control group (N = 35). Benzene in the working atmosphere was significantly higher in 1987 compared to 1992, but was always lower than the current Croatian permissible concentration of 50 mg m-3 (in the near future this value will be changed to 15 mg m-3). A statistically significant difference was also found in biological markers of benzene exposure between the two periods of the investigation. Increased absorption in the first period occurred because of intensified production in 1987, and this decreased significantly in 1992 because of the war in Croatia. The cytogenetic study showed a significant increase in dicentric chromosomes in exposed groups I and II when compared to the control group. Statistically significant higher SCE frequencies were found in group I compared to the control group and also compared to group II. Between exposed group II and the controls no statistically significant difference in SCEs was found. Comparing the same 11 workers present in both periods the results showed no difference in chromosome aberrations between the two periods of examination. SCE frequencies were significantly higher in 1987 when greater benzene absorption occurred, confirmed by biomarkers of benzene exposure. The presented results indicate that genotoxicity may occur in workers exposed to low levels of benzene in the shoe industry.

Visual evoked potentials in individuals exposed to long-term low concentrations of toluene.

An investigation of visual evoked potentials was carried out in two groups of subjects; 49 workers employed in a printing-prss where toluene has been used exclusively as an organic solvent for the last 30 years, and 59 workers not occupationally exposed to any known neurotoxic substances. The average length of work service in the printing-press was 21.4 years. The level of exposure was assessed by determination of the concentration of toluene in peripheral blood, the concentration of hippuric acid and ortho-cresol in urine in subgroups of subjects chosen at random from both groups. N75, P100 and N145 waves of the pattern reversal visual evoked potentials were analyzed. In the group of exposed subjects, significantly greater amplitudes were found in all waves, with significantly longer latency of the P100 wave.

Assessment of urban population exposure to trichloroethylene and tetrachloroethylene by means of biological monitoring.

Exposure of the general population to trichloroethylene and tetrachloroethylene under normal environmental conditions, achieved with biological monitoring, was assessed, and the possible influence of these compounds via drinking water on the body burden was revealed. A total of 79 subjects with no known solvent exposure was selected, by stratified sampling, from the residents of the city of Zagreb. Trichloroethylene and tetrachloroethylene were determined in blood, and trichloroethanol and trichloroacetic acid were determined in plasma and urine. Drinking water samples were also analyzed for trichloroethylene and tetrachloroethylene. Concentrations of trichloroethylene and tetrachloroethylene in blood, trichloroacetic acid in plasma, trichloroacetic acid in urine, trichloroethylene in drinking water, and tetrachloroethylene in drinking water were as follows: < 0.015 to 0.090 micrograms/l, < 0.010 to 0.239 micrograms/l, 8.6 to 148.1 micrograms/l, 1.67 to 102.3 micrograms/24 h, < 0.05 to 22.93 micrograms/l, and 0.21 to 7.80 micrograms/l, respectively. The variation in all results presented is probably a reflection of different environmental contamination with trichloroethylene and tetrachloroethylene in the different city areas. Correlation analyses revealed significant relationships between trichloroethylene and tetrachloroethylene in blood (r = .402, p = .0004); trichloroacetic acid in urine and in plasma (r = .522, p = .0000); and trichloroethylene and tetrachloroethylene in drinking water (r = .800, p = .0000). A division of all parameters into a subgroup (n = 58), taking drinking water concentrations of trichloroethylene above 3 micrograms/l as a basis, demonstrated the same significant relationships as mentioned above.(ABSTRACT TRUNCATED AT 250 WORDS)

A selection of biological indicators in occupational exposure to toluene and xylene.

Results of a comparative study of occupational exposure to toluene and xylene are presented. The study was carried out in a group of 24 workers from a paint factory and aimed to determine the most appropriate exposure indicators for use in biological monitoring. Measurements included toluene and xylene in blood and their metabolites in urine. Toluene in blood proved to be the best indicator of toluene exposure, and both xylene in blood and its only major metabolite methylhippuric acid in urine to be reliable indicators of xylene exposure. The validity of hippuric acid and o-cresol as toluene exposure indicators has not been confirmed.

Assessment of exposure to trichloroethylene and tetrachloroethylene in the population of Zagreb, Croatia.

Human exposure to trichloroethylene (TRI) and tetrachloroethylene (perchloroethylene, PER) through air, food and drinking water was assessed by biological monitoring. By stratified sampling 39 subjects with no known solvent exposure were selected from the residents of the city of Zagreb (the capital of the Republic of Croatia). TRI and PER were determined in blood and their metabolites trichloroethanol (TCE) and trichloroacetic acid (TCA) in plasma and urine. Drinking water samples were also taken for TRI and PER determination. TRI was present in measurable concentrations in 22 subjects (range: 0.026-0.090 micrograms/l) and PER in 31 subjects (range: 0.031-2.540 micrograms/l). TCE was not detected in any of the samples, while TCA was determined in all plasma (range: 13.54-160.42 micrograms/l) and urine samples (range: 1.64-291.76 micrograms/24h). In drinking water samples TRI and PER values were also in a very wide range: 0.69-35.90 micrograms/l and 0.36-7.80 micrograms/l, respectively. The variation of all results presented is most probably a reflection of the different environmental contamination with TRI and PER in the different city areas.

A comparative study of human levels of trichloroethylene and tetrachloroethylene after occupational exposure.

The rate of trichloroethylene (TRI) and perchloroethylene (PER) absorption was investigated in workers who were (1) occupationally exposed to TRI in four dry-cleaning shops (Group 1, n = 10) and (2) occupationally exposed to PER in one dry-cleaning shop (Group 2, n = 18). Concentrations of TRI and PER in blood were analyzed, and concentrations of trichloroethanol (TCE) and trichloroacetic acid (TCA) in blood and urine were analyzed. Results varied widely: PER was found in the blood of workers in group 1, but TRI was not detected in blood from any worker in group 2; most blood samples from group 2 workers did not contain a detectable quantity of TCE, and urine TCE concentrations in this group were very low. During the work week, a significant difference was found in group 1 for TRI in blood and TCE in blood and urine. In group 2, however, the only significant difference during the work week was for PER in blood. Therefore, the most reliable biological indicators for TRI and PER exposure are TCE in blood and PER in blood, respectively.

Metabolic activity of antipyrine in workers occupationally exposed to trichloroethylene.

In order to investigate possible effects of occupational exposure to trichloroethylene (TRI) on the liver cytochrome P-450 dependent monooxygenases, the metabolic activity of salivary antipyrine was determined in workers (I; N = 32) employed in dry-cleaning shops (I-1; N = 17) and in an industrial metal degreasing process (I-2; N = 15). The studies were performed twice: (a) during the working period, (b) and after at least three weeks free of exposure. The control group (II) consisted of 29 subjects with no known exposure to chemicals. Analyses of the solvents used (TRI) showed them to be mixtures. Statistically significant differences were found (P less than 0.01) in antipyrine t1/2 and clearance within the exposed group (Ia:Ib), but not between the exposed (I) and control (II) group. A breakdown of antipyrine pharmacokinetic data by I-1 and I-2 subgroups demonstrated a statistically significant difference in t1/2 (P less than 0.02) and clearance (P less than 0.05) within I-1 subgroup (a:b), in contrast to the I-2 subgroup (a:b). The difference in antipyrine t1/2 between I-1,a and the control group (II) was also statistically significant (P less than 0.05). Although there was no difference in TRI exposure between I-1 and I-2 based on the biological parameters of TRI absorption, the TRI used in I-2 was of higher grade of purity. It can therefore be concluded that TRI itself is not an inducer of liver monooxygenases and that the monooxygenase induction in subgroup I-1 of TRI exposed workers could be due to TRI impurities.