Study of the Genotoxicity of Toluene

Chromosome analysis was conducted for peripheral lymphocytes of 23 printers exposed to toluene concentrations of 590 mg/m³ in a rotary machine workshop and to rotogravure printing inks. The percentages of aberrant cells were 2.30 in the printers and 1.46 in the control group (n = 22) (p < .05). The concentration of hippuric acid in printers was significantly higher than in the control group (p < .01), and the level of blood toluene at the end of the workshift was 0.500 mg/l. The authors also examined rotogravure printing inks—considered a potential source of genotoxic polycyclic aromatic hydrocarbons because they contained carbon black—their use in printing plants, and previous documentation of increased chromosomal aberrations in rotogravure printers. Only milligrams of fluorene and phenanthrene per gram of the printing inks were found; no polycyclic aromatic hydrocarbons with carcinogenic properties were discovered in the inks. The authors used Salmonella typhimurium indicator strains TA 98, TA 100, TA 1537, and YG 1041 in spot tests and indicator strains TA 98 and TA 100 in plate-incorporation assays to determine that there was no bacterial mutagenicity of all four colors of rotogravure inks. Urinary mutagenicity, which was evaluated with a microsuspension assay containing YG 1041 indicator strain both in the presence and absence of metabolic activation, was also studied. No significant difference in bacterial mutagenicity was found between the exposed and control groups. The increased percentage of aberrant cells in printers can be explained by exposure to genotoxicants that are not excreted in urine. Toluene was the most likely cause of the aberration.     

Blue rayon and Salmonella/microsome assay in the evaluation of coastal water quality

OBJECTIVE: To develop a strategy for water quality monitoring for the presence of genotoxins and polycyclic aromatic hydrocarbons. METHODS: A study was carried out in Santos estuary, Southern Brazil, in 2002. Two sampling sites with different concentration levels were selected and evaluated in different samplings using blue rayon hanging technique, chemical analyses, and Salmonella/microsome assay with bacterial strains sensitive to different compounds. The extracts were tested using the Salmonella/microsome assay in microsuspension with the strains TA98, TA100, YG1041, and YG1042 in the absence and presence of metabolic activation and through chemical analyses. RESULTS: Site 1, which had high concentrations of polycyclic aromatic hydrocarbons in its sediment, showed more often positive results in the Salmonella/microsome assay as well as higher polycyclic aromatic hydrocarbons concentrations in both samplings compared to site 2, which was less contaminated. YG1041 strain showed to be the most sensitive allowing for comparisons between the sites with different levels of contamination. CONCLUSIONS: The combination of the blue rayon hanging technique with the Salmonella/microsome assay using YG1041 strain and chemical analyses were effective in recovering genotoxins as well as polycyclic aromatic hydrocarbons tested in this study. Therefore this strategy seems to be adequate for water quality monitoring in Santos estuary.     

应用菌株YG1024对吸烟者尿致突变性的研究

应用鼠伤寒沙门氏菌株ＴＡ９８及其富含硝基还原酶的衍生菌株ＹＧ１０２１和富含０－乙酰转移酶的衍生菌株ＹＧ１０２４检测了吸烟者尿的致突变性。结果表明，在有鼠肝Ｓ９存在时吸烟者尿样对菌株ＹＧ１０２４的致突变作用明显高于ＴＡ９８，而相同条件下菌株ＹＧ１０２１的回变性与ＴＡ９８大致相同。证明菌株ＹＧ１０２４在检测吸烟者尿致突变性上比传统的＂敏感＂菌株ＴＡ９８更为敏感。同时也提示吸烟者尿中的致突变物主要是芳香胺类物质。     

2种燃料燃烧颗粒物致突变性及其联合作用

目的比较液化石油气（LPG）燃烧颗粒物和蜂窝煤燃烧颗粒物的致突变性以及二者的联合作用。方法采用Ames法,应用鼠伤寒沙门菌突变型菌株TA 98及其衍生菌株YG 1021和YG 1024进行致突变试验研究,并根据致突变试验结果评价其联合作用。结果2种颗粒物对YG菌株的致突变作用均高于对TA 98的作用;LPG燃烧颗粒物比蜂窝煤燃烧颗粒物的致突变作用更强,前者约相当于后者的8倍;二者的联合作用呈相加类型。结论煤和LPG燃烧颗粒物均具有很强的直接和间接致突变作用,主要致突变作用来源于硝基和胺基多环芳烃,2种颗粒物同时存在可加大致癌风险。     

Response of solvent-exposed printers and unexposed controls to six-hour toluene exposure

The acute effects of toluene were studied in 43 male printers and 43 control subjects matched according to sex, age, educational level, and smoking habits. The mean age of the subjects was 36 (range 29-50) years. The printers had been exposed to solvents for 9 to 25 years during employment at flexo and rotogravure printing plants, while the controls had no history of solvent exposure. Each subject was exposed once in a climate chamber to either 100 ppm of toluene or clean air for 6.5 h preceded by a 1-h acclimatization period. The effects of toluene were measured from subjective votes with linear analogue rating scales on 16 items, and on the performance of 10 different tests measuring psychomotor skills, perceptual skills, and vigilance. Exposure to 100 ppm of toluene compared with exposure to clean air caused discomfort with complaints of low air quality, strong odor, fatigue, sleepiness, a feeling of intoxication, and irritation of the eyes, nose and throat. Furthermore, the subjects exposed to toluene showed decreased manual dexterity, decreased color discrimination, and decreased accuracy in visual perception. There was no significant difference in the effects of toluene on printers compared to those of toluene on controls, but tendencies toward a greater sensitivity were seen for the printers in two tests.     

Occupational exposure to toluene: neurotoxic effects with special emphasis on drinking habits

Summary Neurotoxic effects of toluene were examined in 43 male rotogravure printers exposed to toluene (age 27–63, mean 41 years; duration of exposure 11–40, mean 22 years) and 31 male offset printers of the same age with slight exposure to aliphatic hydrocarbons. A neurological examination, tests for autonomic nervous function, electroencephalography, psychological tests and computerized tomography of the brain were carried out in addition to a standardized interview. Exposure levels were evaluated for each person separately on the basis of his work history and the results of an earlier study on exposure levels at the same printing shops. Besides a thorough history of alcohol consumption, information about the printers' drinking habits was obtained from the occupational health care centers of the printing shops. The examinations found only slight abnormalities, and there were no statistically significant group differences in the prevalences of abnormalities. No correlations between the abnormalities and the exposure indices were found either. One of the retired workers, however, who had been exposed to high toluene concentrations for over 40 years, had been diagnosed as having chronic organic solvent intoxication. Heavy drinkers of alcohol were clearly more common in the toluene-exposed group. This study detected no clinically significant abnormalities attributable to toluene alone among workers exposed to 68–185 ppm (mean 117) of toluene for over 10 years. The connection between alcohol consumption and toluene exposure is interesting and deserves further study.     

Assessment of the mutagenic potency of sewage sludges contaminated with polycyclic aromatic hydrocarbons by an Ames sludges for fluctuation assay

The mutagenicity of crude extracts and subfractions of two samples of a reference sewage sludge material and two sewage sludges from two wastewater treatment plants (WWTP), one urban and the other one urban mixed with industrial, was assessed using an Ames fluctuation assay based on 384-well microtiter plates with liquid cultures. Crude extracts of sludges were obtained by ultrasonic extraction with dichloromethane/methanol, and further column fractionation yielded two fractions, one of which containing mutagenic polycyclic aromatic hydrocarbons (PAHs). Quantitative analysis performed by gas chromatography-mass spectrometry gave sum concentrations of the 16 PAHs listed as priority pollutants by the U.S. Environmental Protection Agency at levels between 1,305 and 2,442 microg/kg. Subjecting crude extracts and column fractions to the mutagenicity assay with Salmonella strains TA98 and TA 100 provided good qualitative correlation between the presence of mutagenic PAH and the induction of gene mutations. In general, the crude extracts and the PAH-fractions induced positive responses in the assay with both bacterial strains on metabolic activation by S9 rat-liver homogenate, whereas direct-acting mutagens were not detectable. In the assay with the real sludge samples of two different WWTPs, TA98 proved to be more sensitive than TA100; however, similar sensitivities of the tester strains were observed for two reference sewage sludge materials of the same origin. The outcomes of the Ames fluctuation assay demonstrated its performance as a cost-effective and relatively rapid screening tool to assess the genotoxic potential of complex environmental samples.     

Validity of mutagenic activity as an indicator of river water pollution

Objectives To investigate if mutagenicity could be expressed by known water pollution indicators, we determined the mutagenic activity of blue rayon extracts from sampled river water with the Ames test utilizing new strains of bacteria, and compared the results with those of known indicators of water pollution. Methods Water samples were collected by the blue rayon adsorption method at sixteen sites in six rivers in the North Kyushu district. The Assay of mutagenicity was carried out using the Ames test. The test strains wereSalmonella typhimurium TA100, YG1024, YG1041 and YG1042. B(a)P, Trp-P-1 and Trp-P-2 were quantified by HPLC. Determinations of SS, BOD, COD, T-N, T-P, DOC, and A₂₆₀/DOC were performed. Results The extracts from five sampling sites showed higher mutagenicity toward strain YG1024 with or without S9mix, and the extracts from two of these five sites showed higher mutagenicity toward strain YG1041 with and without S9mix. However, the water pollution indicators did not show specific trends that were consistent with the mutagenic activity. Conclusions Since the mutagenic activity of river water could not be predicted using known water pollution indicators, we recommend that biological examinations such as mutagenicity tests be added to the indicators that are currently in use.     

Application of the Salmonella mutagenicity assay and determination of polycyclic aromatic hydrocarbons in workplaces exposed to petroleum pitch and petroleum coke

Summary Workplaces of an Italian carbon electrode factory, exposed to petroleum pitch and petroleum coke, were studied using a coupled chemical and biological approach to evaluate occupational mutagenic/carcinogenic hazards. Analytical procedures for the determination of polycyclic aromatic hydrocarbons (PAH) and Salmonella/microsome mutagenicity tests (with TA98 and TA 100 strains) were performed on both industrial ingredients (pitch and coke) and airborne particulate matter of the working environment, after fractionating by sequential Soxhlet extractions with four organic solvents of increasing polarity (benzene, chloroform, methanol and acetone). The results showed: (a) the presence of extraordinarily high PAH (carcinogenic and noncarcinogenic) contents in the benzene extracts of petroleum pitch (3.6 wt% of total PAH) and of airborne particulate samples (up to 0.35 wt% of total PAH), in correlation with very high indirect (after metabolic activation) mutagenic responses of benzene extracts with strain TA98; (b) very high indirect mutagenic responses in the other extracts of the airborne particulate samples (especially with strain TA98); (c) the production during the processing at high temperatures of directly acting mutagens (without metabolic activation) which were absent in the starting materials and their release in the air of workplaces. The comparison of chemical analytical and mutagenicity data has proved to be an interesting approach for better defining the relative health hazards due to occupational exposure to potentially mutagenic/carcinogenic petroleum products.     

Influence of ethanol and methanol gasoline blends on the mutagenicity of particulate exhaust extracts

TheSalmonella mutagenicity test was used to evaluate the influence of alcohol fuel extenders on the genetic toxicity of particulate exhaust extracts. Four spark-ignition engine equipped vehicles were operated on gasoline alone, 10% blends of ethanol or methanol in gasoline, and a commercially available “gasohol.” The tests were conducted on a chassis dynomometer and the particulate exhaust was collected on high volume filters after dilution in a tunnel. The vehicles used were a 1980 Chevrolet Citation, a 1980 Mercury Monarch, a 1981 Ford Escort and a 1981 Oldsmobile Cutlass. Dichloromethane extracts of the exhaust particles from all tests were mutagenic inSalmonella typhimurium strains TA 100 and TA 98. The extracts were less mutagenic in the nitroreductase deficient strains TA 98NR and TA 98DNPR suggesting that nitro substituted polycyclic aromatic hydrocarbons may be responsible for part of the mutagenicity. In all the alcohol blended fuel tests, the mass of particle associated organics emitted from the exhaust was lower than that observed during the control tests using gasoline alone. Thus, in most cases, estimates of the emission of mutagenic combustion products from the exhaust were lower in the alcohol blend tests.     

Mutagenicity of a polar portion in the neutral fraction separated from organic extracts of airborne particulates

Six fractions were prepared from an organic extract of airborne particulate matter collected between June 1983 and May 1984 by liquid-liquid partition and silica gel column chromatography. These fractions were assayed for their mutagenicities by the AmesSalmonella and sister chromatid exchange tests, with and without metabolic activation. After metabolic activation, a moderately polar fraction had the greatest mutagenicity per weight inSalmonella typhimurium strains TA98 and TA100. Ten subfractions were subsequently obtained from this fraction by high-pressure liquid chromatography, which were subjected to capillary gas chromatography with a nitrogen-phosphorous selective detector, and gas chromatography-mass spectrometry, in addition to further investigation of their mutagenicities. The characterized components were classified into polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (containing ketones, quinones, coumarines and aldehydes), and azaarenes.     

Urinary mutagenicity in chemical laboratory workers exposed to solvents

Solvents represent an important group of environmental pollutants to which people are exposed daily in the workplace. The physico chemical properties of solvents may result in disturbances to cellular structures, including damage to DNA. However, the effects of mixtures of solvents are not well known. Mutations caused by environmental agents are related to cancer development and other degenerative diseases. The work in a research laboratory that uses several types of solvents is equally predisposed to these hazards. In this study, we evaluated the mutagenicity of urine from 29 subjects exposed occupationally to solvents in a chemistry research laboratory and 29 subjects without occupational exposure (controls). Urine samples were collected in polyethylene containers at the end of the work shift. For the concentration and extraction of urine samples the XAD-2 resin was used with acetone as an eluting agent. Several strains of Salmonella typhimurium (TA100, TA98, TA97a, TA1535, YG1024) should be used to assess mutagenic susceptibilities among workers exposed to organic solvents. Different doses of extract (1.5; 3.0; 6.0 and 12.0 ml equivalents of urine per plate) were tested on S. typhimurium strains TA100 and YG1024, with and without metabolic activation. The mutagenic activity, measured in Salmonella typhimurium YG1024 with S9 mix, was significantly greater in urine from workers than from controls (p相似文献   

Characterization of publication rotogravure press emission rates and compositions

Emission compositions and rates were determined during production for a publication rotogravure press room at a large rotogravure printing company. The press room housed a single 4-color, 8-print-stand press, with an 84" paper web. Average press speed was 1800 feet per minute. Data were collected over a 2-day period and included measurements of ventilation, room area concentrations, duct exhaust compositions, amount and composition of inks used, and worker exposures. These data were used with mass balance models that were appropriate for the workspace. Toluene comprised more than 90 percent of the inks and solvents and accounted for more than 90 percent of the press emissions. Average toluene emissions during press operation and press off conditions were 222 kg/hr and 8-38 kg/hr, respectively. The uncontrolled toluene emission on the basis of printed paper throughput was 3 g/m2. Of the total toluene released, 90 percent was captured by the local exhaust ventilation. The measured control efficiency was much lower than the average efficiency of 97 percent for the month of the test reported by the plant. A mass balance model evaluation demonstrated that only the lower efficiency was consistent with measured room concentrations. Using the measured emission rates and actual monthly press on and press off conditions, the difference in efficiency for the plant (10 rotogravure presses) extrapolates to the additional release to the workspace and ambient environment of over 700 tons/yr of toluene.     

Mutagenicity of organic pollutants adsorbed on airborne particles in the center of Wrocław

With Ames assay there was examined mutagenicity of airborne particles that was sampled in summer and winter in centre of Wroc?aw; there were also examined fractions of aliphatic hydrocarbons, aromatic hydrocarbons and polar compounds obtained from suspended matter extracts suspended with column chromatography. The strain of Salmonella typhimurium TA 98 was used with metabolic activation with S9 mix fraction. The samples collected in winter was more mutagenically active than the one sampled in summer. Mutagenicity of suspended matter sampled in summer was determined by compounds that were of more polar character than polycyclic aromatic hydrocarbons soluble in hexane. There was observed a decrease in mutagenic activity of samples in summer due to metabolic activation. There were few polycyclic aromatic hydrocarbons on the dust sampled in summer and they did not display mutagenic activity. Mutagenicity of air particles sampled in winter was determined by polycyclic aromatic hydrocarbons soluble in hexane and polar compounds. There was observed an increase in their mutagenic activity due to metabolic activation. This demonstrates that among them there are present promutagens, which, in mammals, undergo enzymatic transformation to compounds of direct mutagenic activity. Fractions of aliphatic hydrocarbons in the examined range of concentrations did not display mutagenic activity neither in summer nor in winter, both with and without metabolic activity.     

Monitoring exposure of hospital personnel handling cytostatic drugs and contaminated materials

A study was undertaken to evaluate the urine mutagenicity of 63 individuals working in four hospital departments. The exposed group included 38 subjects who were exposed to various cytostatic drugs and/or contaminated material from treated patients. The control group included 25 individuals of the hospital personnel. Urine mutagenicity was monitored by the Ames test using tester strains TA 98 + S9 Mix and TA 102 — S9 Mix. Urine samples were collected before and after the working periods. A total of 29/116 (25%) urine samples were mutagenic for either strain. Among the mutagenic samples, 24/29 were mutagenic for tester strain TA 98 exclusively. No significant correlation could be found between occupational exposure to cytostatic drugs and urine mutagenicity evaluated by the strain TA 98 + S9 Mix. Smoking was the main environmental factor that modulated urine mutagenicity with TA 98. Three subjects in the exposed group had mutagenic urine samples at the end of the working period with strain TA 102 — S9 Mix. This mutagenicity was related to occupational exposure to cisplatin. In the control group, one individual had mutagenic samples before and after the working period. Assessing occupational exposure to cytostatic drugs with strain TA 102 requires additional studies to determine environmental mutagens which can be detected by this strain.     

Neurasthenic complaints and psychometric function of toluene-exposed rotogravure printers

In 1985, 30 rotogravure printers exposed to toluene for 4-43 years (median 29) were examined by means of interviews and psychometric testing. They were 33-61 years of age (mean 50). Comparisons were made with a reference group of 72 men aged 27-69 (mean 47). The referents had never been exposed to solvents and were all in good health. The printers were employed by two Swedish companies. The mean exposure levels were 43 and 157 mg/m3 of toluene, respectively, at the two printing shops. Before 1980 the exposure levels had exceeded 300 mg/m3. On Monday mornings, before psychometric testing at the department of occupational medicine, toluene was measured in venous blood samples from most of the exposed subjects. A high proportion of the printers reported fatigue (60%), recent short-term memory problems (60%), concentration difficulties (40%), mood lability (27%), and other neurasthenic symptoms. In the psychometric tests their performance was poorer than the reference group's in most of the tests applied. Even performance on the synonyms test, usually considered resistant to mild brain affliction, was worse in the group of printers. Adjusting for this difference in the group comparisons reduced the group differences substantially. Alcohol consumption above 200 g/week was found to reduce the subjects' psychometric function more than toluene exposure. The printers' sum of neurasthenic complaints correlated negatively with their score in several tests. Exposure variables showed only weak associations with test results. Blood toluene levels were positively correlated with scores in spatial tests. The direction of the correlations suggests that the influence of acute pharmacologic effects is undetectable on Monday mornings before work. In conclusion, we found that exposure to toluene at levels below 157 mg/m3 following long-term exposure did induce neurasthenic problems and might reduce psychometric test performance.     

Handling of cytostatic drugs and urine mutagenesis

Summary As part of a French national epidemiologic study on human reproduction among hospital personnel, we investigated urine mutagenicity of nurses and personnel from oncology units exposed to cytostatic drugs. During a first series of experiments, urine mutagenicity of 47 subjects working in six oncology units was investigated in the Marseille regional's hospital. A control group of 37 individuals working in one cardiology clinic was also included. Urinary mutagens were extracted on XAD-2 resin and tested by two bacterial mutagenicity tests: the Ames test with tester strains Salmonella typhimurium TA 97, TA 98, TA 100 and TA 102 with or without metabolic activation (S9 MIX) and the SOS Chromotest with tester strain Escherichia coli PQ 37-S9 MIX. Bactericidal activity towards the tester strains was found in 40% of the urine samples (36/90). During a second series of experiments, urine mutagenicity of 17 office clerks was also investigated. Toxicity was found in six of the 21 urine samples. No significant difference of toxicity distribution and no relationship between toxicity and cigarette smoking were found. Qualitative analysis of the data showed no significant difference among the exposed groups and the control group (Chi 2 = 0.529, df = 2) with tester strain TA 98 + S9 MIX. Cigarette smoking was found to be the main factor of increased urinary mutagenicity (Chi 2 = 0.529, df = 1). Quantitative analysis of the data showed that mutagenic potencies varied from 0.332 ±0.539 revertants/mg creatinine to 7.226 ± 6.743 revertants/mg creatinine with TA 98 + S9 MIX. A relationship between the number of cigarettes smoked and mutagenic potency was found (Spearman rank coefficient r _s = 0.412, P < 0.05). One urine sample was found to be mutagenic with tester strain TA 102 and PQ 37.     

Correlation between mutagenicity of airborne particles and air pollution parameters in eleven Italian towns

Organic extracts from airborne particles collected in 11 Italian towns between February and April, 1988, were tested for mutagenicity on TA98 and TA100 (± S9), and their nitroreductase (NR) deficient Salmonella strains, by the use of the Ames plate incorporation assay. Mutagenic responses were fitted by an equation which takes into account toxic effects on tester organisms. Generally parallel responses were obtained with the two Salmonella strains, but the TA98 gave, mostly, higher increases of revertants over the control level. No dramatic decreases in mutagenicity were observed with the NR derivative strains, except in a few cases with TA98NR and, more frequently, with TA100NR strains. During air sampling, temperature, atmospheric pressure, light, wind strength and direction, SO₂, CO, NO₂, O₃ and non‐methanic hydrocarbons (NMHC) concentrations were continuously monitored. Meteorological variables seem not to be significantly correlated with mutagenicity variations, while the highest correlation (r = 0.91) was observed between induced reversion in TA98 (+ S9) and NMHC concentration in air. Therefore, in spite of the wide range of different types of towns included in the study, air NMHC concentration can be considered a good predictor for the mutagenicity of the total organic material extracted from particles of urban air.