Acquired dyschromatopsia in combined exposure to solvents and alcohol

Hypothesis: Does occupational exposure to solvents in combination with alcohol intake give rise to acquired color vision defects? Method: A total of 138 individuals exposed to solvents (toluene, xylene, trichloroethylene, tetrachloroethylene) were examined using Lanthony’s D-15 test and compared with 100 nonexposed controls. The extent of color vision loss was quantitatively assessed based on Bowman’s color confusion index (CCI). A cumulative exposure index was calculated from the hours of exposure per day and the years of exposure. In 30 persons who were exposed to trichloroethylene and tetrachloroethylene, urinary trichloroacetic acid was assessed as a parameter of exposure. Alcohol intake was calculated as based on interviews of patients in grams of ethyl alcohol per week. Results: Individuals who consumed more than 250 g alcohol/week and were simultaneously exposed to solvents showed a significantly elevated CCI (P = 0.0044). No significant correlation emerged between trichloroacetid acid excretion in the urine or the cumulative exposure index and the CCI. Conclusion: The combination of alcohol intake and occupational exposure to solvents discloses the risk of acquired subclinical color vision defects.     

Solvent neurotoxicity in vehicle collision repair workers in New Zealand

ObjectivesTo assess whether solvent use and workplace practices in the vehicle collision repair industry are associated with symptoms of neurotoxicity in spray painters and panel beaters (auto body repair workers).MethodsNeurobehavioural symptoms were assessed using a cross-sectional study design in 370 vehicle collision repair and 211 reference workers using the EUROQUEST questionnaire. Full-shift airborne solvent levels were measured in a subset (n = 92) of collision repair workers.ResultsSolvent exposures were higher in spray painters than in panel beaters, but levels were below current international exposure standards. Collision repair workers were more likely to report symptoms of neurotoxicity than reference workers with ORs of 2.0, 2.4 and 6.4 (all p < 0.05) for reporting ≥5, ≥10 and ≥15 symptoms respectively. This trend was generally strongest for panel beaters (ORs of 2.1, 3.3 and 8.2 for ≥5, ≥10 and ≥15 symptoms respectively). Associations with specific symptom domains showed increased risks for neurological (OR 4.2), psychosomatic (OR 3.2), mood (OR 2.1), memory (OR 2.9) and memory and concentration symptoms combined (OR 2.4; all p < 0.05). Workers who had worked for 10–19 years or 20+ years in the collision repair industry reported consistently more symptoms than those who had only worked less than 10 years even after adjusting for age. However, those who worked more than 20 years generally reported fewer symptoms than those who worked 10–19 years, suggesting a possible healthy worker survivor bias.ConclusionsDespite low airborne solvent exposures, vehicle collision repair spray painters and panel beaters continue to be at risk of symptoms of neurotoxicity.     

Effect of hydroxylated solvents on the active constituents of Salvadora persica root “Siwak”

Previously, the antimicrobial activity of Salvadora persica was traced to benzyl isothiocyanate. In the present study known inactive compounds were isolated from extracts obtained by different solvents including β-amyrin, β-sitosterol, stigmasterol glucoside, benzyl cyanide and sulphur. However, some inactive compounds were present only in the ethanol and methanol extracts. This observation indicated that these compounds most likely are artifacts resulted from interaction with the solvents used in extraction. Pure benzyl isothiocyanate was kept with different solvents for 72?h and after TLC study they were heated under reflux for 8?h to explore the possibility of interactions. Only solvents with OH groups reacted with benzyl isothiocyanate and gave products similar to those isolated from the alcohol extracts. In conclusion extraction of S. persica with hydroxylated solvents will alter the structure of the active compound benzyl isothiocyanate and leads to loss of antimicrobial activity.     

Subchronic inhalation neurotoxicity studies of ethyl acetate in rats

Rats were exposed to 0, 350, 750 or 1500 ppm of ethyl acetate by inhalation for 6 h per day, 5 days per week for 13 weeks. Functional observational battery (FOB) and motor activity tests occurred on non-exposure days during weeks 4, 8 and 13, after which tissues were microscopically examined for neuropathology. A subset of rats was monitored during a 4-week recovery period. Exposure to 750 and 1500 ppm, diminished behavioral responses to unexpected auditory stimuli during the exposure session and appeared to be an acute sedative effect. There were no signs of acute intoxication 30 min after exposure sessions ended. Rats exposed to 750 and 1500 ppm had reduced body weight, body weight gain, feed consumption, and feed efficiency, which fully or partially recovered within 4 weeks. Reductions in body weight gain and feed efficiency were observed in male rats exposed to 350 ppm. The principal behavioral effect of subchronic exposure was reduced motor activity in the 1500 ppm females, an effect that was not present after the 4-week recovery period. All other FOB and motor activity parameters were unaffected, and no pathology was observed in nervous system tissues. Operant sessions were conducted in another set of male rats preconditioned to a stable operant baseline under a multiple fixed ratio-fixed interval (FR-FI) schedule of food reinforcement. FR response rate, FR post-reinforcement pause duration, and the pattern of FI responding were not affected during or after the exposure series. In contrast, within-group FI rate for the treatment groups increased over time whereas those of the controls decreased. A historical control group, however, also showed a similar pattern of increase, indicating that these changes did not clearly represent a treatment-related effect. Results from these studies indicate a LOEL of 350 ppm for systemic toxicity based on the decreased body weight gain in male rats, and a LOEL of 1500 ppm for neurotoxicity based on the transient reduction in motor activity in female rats. In conclusion, there was no evidence that subchronic exposure up to 1500 ppm ethyl acetate produced any enduring neurotoxic effects in rats.     

Biological effects of imidazolium ionic liquids with varying chain lengths in acute Vibrio fischeri and WST-1 cell viability assays

Detailed biological studies of methyl- and some ethylimidazolium ionic liquids in luminescent bacteria as well as in the IPC-81 (leukemia cells) and C6 (glioma cells) rat cell lines are presented. Effective concentrations in these test systems are generally some orders of magnitude lower than effective concentrations [corrected] of the conventional solvents acetone, acetonitrile, methanol, and methyl t-butyl ether. No general influence of the anionic compound in the ionic liquids on toxicity could be found, although they seem to modulate toxicity in some cases. The clear influence of the alkyl chain length on toxicity was quantified by linear regression analysis. Alkyl chain length of the longer alkyl chain was varied from 3 to 10 carbon atoms. Consequences for a design of sustainable alternative solvents are briefly sketched.     

A case–control study of occupational exposures and systemic sclerosis

Objectives A case–control study was conducted in Verona, Italy, to assess the relationship between occupation, occupational exposures and systemic sclerosis (SSc).Methods Fifty-five cases (46 female and nine male) and 171 controls were recruited. Interviews provided work histories, including job titles, industry and likelihood of occupational exposure to silica, hand–arm vibration, organic solvents, and other chemicals. Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated.Results Female teachers (OR 3.4, 95% CI 1.2–10.1) and textile workers (OR 2.1, 95% CI 1.0–4.6) were at an increased risk of SSc. Compared with those never exposed, age-adjusted and gender-adjusted ORs were 2.3 (95% CI 1.0–5.4) among subjects exposed to organic solvents, 2.5 (95% CI 0.8–8.0) for exposure to selected chemicals, 1.7 (95% CI 0.4–7.6) for exposure to silica, and 1.5 (95% CI 0.5–4.8) for usage of vibrating tools. When data analysis was stratified according to gender, only men showed a significant increase in risk for exposure to solvents and selected chemicals.Conclusions The findings of this study tend to support the role of organic solvents and certain chemicals in SSc causation. The association with teaching and working in the textile industry suggests that other exposures are involved in the aetiology of SSc among women. However, because of the small number of subjects, particularly in stratified analyses, chance cannot be ruled out as an explanation of some findings of this study.     

Multiple exposure to solvents in the workplace

Conclusions In conclusion, it must be stressed that scientific studies need to be undertaken in the near future to solve the various problems mentioned above. These studies should also take account of all the non-occupational factors that, may alter the toxicokinetics and the toxicodynamics of solvents. At present, however, existing data obtained both from experimental research in animals and in volunteers and from studies carried out in workers liable to occupational exposure can be used in preparing lists similar to those we have proposed in Table 1, in which metabolic interferences are reported for the various substances. Although incomplete and only indicative, these lists may be a useful guide to the correct preventive measures to be implemented in various workplace situations. They should, at the very least, stimulate readers to extend their knowledge of the toxicology of combined exposure to solvents.     

Changes in markers of oxidative status in brain,liver and kidney of young and aged rats following exposure to aromatic white spirit

 Levels of glutathione and activity of glutamine synthetase were assayed in organs of rats following inhalation of a heterogeneous solvent mixture containing both aliphatic and aromatic hydrocarbons. This mixture was administered for 3 weeks (6 h daily) at two levels in the inhaled air (400 and 800 ppm) to young adult (5-month-old) and aged (14-month-old) rats. Depression of levels of glutamine synthetase in the P2 fraction of kidney was observed, which was more severe in aged than young adult rats. Glutamine synthetase is a cytosolic enzyme especially susceptible to oxidative damage. A parallel depression of this enzyme was also seen in the corresponding hepatic fractions. However, levels of glutamine synthetase in the hippocampus were elevated by this exposure. Glutathione levels were depressed in P2 fractions of livers of exposed rats, and also in the corresponding renal fraction. Glutathione concentration was unchanged in cerebral fractions. Overall results were interpreted to imply that pro-oxidant events were elevated in kidney and liver following prolonged inhalation of the solvent mixture. The changes found in brain tissue did not reveal evidence of oxidative stress but, however, suggested that glial activation was taking place. Received: 4 August 1994 / Accepted: 19 October 1994     

Individual serum bile acids in apprentice spray painters in association with solvent exposure

The effects of exposure to solvents on serum bile acids were investigated by comparing a group of apprentice vehicle spray painters (exposed group) with one of apprentice electricians. Apprentice spray painters from the study were subdivided into high-and low-solvent-exposure groups. Concentrations of individual serum bile acids (SBA) were measured and compared with conventional liver function tests (LFTs). Total, free, glycine-and taurine-conjugated SBA were consistently found to be present at higher levels in the spray painters than in the electricians, even at the beginning of the apprenticeship. Total SBA tended to increase in spray painters with increasing years of exposure during the apprenticeship, but this was significant at only one time point. No rises were observed over the sampling period in electricians. The mean values of individual and total SBA concentrations were all found to be higher in the high-exposure group than in the low-exposure group, with some differences reaching statistical significane. None of the routine liver biochemistry parameters was different between spray painters and electricians. γ-Glutamyl transferase (GGT) was the only enzyme found to be significantly different between the high-and low-exposure groups, but all values were within the normal range. This study suggests that occupational exposure even to low levels of solvent mixtures results in increases in SBA. The increased SBA may be indicative of a subclinical liver dysfunction. Alternatively, they may reflect solvent exposure only, with the raised levels having no pathologic implication or consequence. The views expressed in this article are those of the authors and do not necessarily reflect those of the National Occupational Health and Safety Commission     

干洗溶剂残留的安全评价与限量控制

干洗服务的环境无害技术溶剂和溶剂残留的安全评价体现了绿色消费所关注的社会环境权益，通过生命周期评价管理与清洁生产技术相融合，将污染预防和治理贯穿于整个生产过程和消费过程，为洗衣业提供了一种摆脱使用有毒溶剂带来的健康、环境和社会责任问题的有效途径。