Neuroendocrine effects in printing workers exposed to toluene.

The effect of exposure to toluene on plasma concentrations of testosterone, prolactin, luteinising (LH) and follicle stimulating (FSH) hormones was investigated in 47 rotogravure printers (time weighted average air toluene below 80 ppm; blood toluene concentration post-shift 0.19-7.99 mumol/l) and compared with a reference group. Increasing exposure concentrations of toluene (concentrations less than 5 to greater than 45 ppm) were significantly associated with decreasing plasma concentrations of LH (tau = -0.21, p = 0.003) and testosterone (tau = -0.25, p = 0.02). No correlation was found between cumulative exposure (ppm x years) and plasma hormone concentrations. The associations with exposure were present even when nine printers with heavy alcohol consumption were excluded. The study indicates an effect of low toluene exposure on the hypothalamus-pituitary axis, with a secondary decrease in testosterone secretion.     

Menstrual function in workers exposed to toluene.

Rates of menstrual disorders were studied in 231 female production workers with high exposure to toluene (mean 88 (range 50-150 ppm) in a factory manufacturing audio speakers and compared with a control group of 58 female production workers in other departments in the same factory who had little or no exposure to toluene (0-25 ppm). An external community control group of 187 working class women under routine care at public maternal and child health centres were also studied. Detailed menstrual and reproductive histories were obtained by personal interview using a structured questionnaire. The rates for dysfunctional uterine bleeding (cycle irregularity and prolonged or heavy menstrual bleeding) were similar in all groups. Dysmenorrhoea seemed to occur more often in the women highly exposed to toluene compared with women at maternal and child health centres, but not compared with factory controls with low exposure to toluene. There was no evidence that dysfunctional uterine bleeding was likely to result from exposure to toluene. It is uncertain whether dysmenorrhoea was associated specifically with exposure to toluene, as other behavioural and work related factors may also result in dysmenorrhoea.     

甲苯对作业工人健康的影响

为探讨甲苯与人体健康的关系 ,以甲苯作业工人126人为接触组 ,不接触甲苯的工人124人为对照组 ,进行职业性健康检查 ,对已婚作业女工进行生殖机能回顾性调查 ,接触组作业工人头昏、乏力、出血倾向、咽部充血、红细胞低下、血红蛋白低下、经量过多、自然流产发生率均较对照组高 ,且有统计学意义。     

Neuroendocrine effects of styrene on occupationally exposed workers

The serum levels of prolactin (PRL), human growth hormone (HGH), thyroid-stimulating hormone (TSH), and the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured in 30 females exposed to about 130 (range 65-300) ppm of styrene in the air and in 30 age-matched referents to show whether styrene exposure influences the dopaminergic tuberoinfundibular system (TIDA). The exposed subjects' serum levels of PRL were more than double the reference values and were significantly related to the urinary excretion of styrene metabolites, ie, to the sum of mandelic acid (MA) and phenylglyoxylic acid (PGA) in the "next-morning" urine spot sample. Such a relationship still proved to be statistically significant after the removal of the effects of age and duration of exposure with the method of partial correlation. The serum concentrations of HGH in the exposed workers were also higher than in the reference group. Though within the reference levels, the TSH values of the exposed subjects were significantly related to the urinary excretion of MA and PGA. These results are consistent with the dose-dependent depletion in tuberoinfundibular dopamine after experimental styrene exposure of rabbits.     

Risk of spontaneous abortion in workers exposed to toluene.

Rates of spontaneous abortions were determined using a reproductive questionnaire administered by personal interview to 55 married women with 105 pregnancies. They were employed in an audio speaker factory and were exposed to high concentrations of toluene (mean 88, range 50-150 ppm). These rates of spontaneous abortion were compared with those among 31 women (68 pregnancies) who worked in other departments in the same factory and had little or no exposure to toluene (0-25 ppm), as well as with a community control group of women who underwent routine antenatal and postnatal care at public maternal health clinics (190 women with 444 pregnancies). Significantly higher rates for spontaneous abortions were noted in the group with high exposure to toluene (12.4 per 100 pregnancies) compared with those in the internal control group (2.9 per 100 pregnancies) and in the external control group (4.5 per 100 pregnancies). Among the exposed women, significant differences were also noted in the rates of spontaneous abortion before employment (2.9 per 100 pregnancies) and after employment in the factory (12.6 per 100 pregnancies). Almost all the women were nonsmokers and did not drink; other known risk factors such as maternal age at pregnancy, order of gravidity, and race were not likely to explain the results. Thus, specific exposure to toluene seems to be associated with a risk of foetal loss.     

Risk of spontaneous abortion in workers exposed to toluene.

Rates of spontaneous abortions were determined using a reproductive questionnaire administered by personal interview to 55 married women with 105 pregnancies. They were employed in an audio speaker factory and were exposed to high concentrations of toluene (mean 88, range 50-150 ppm). These rates of spontaneous abortion were compared with those among 31 women (68 pregnancies) who worked in other departments in the same factory and had little or no exposure to toluene (0-25 ppm), as well as with a community control group of women who underwent routine antenatal and postnatal care at public maternal health clinics (190 women with 444 pregnancies). Significantly higher rates for spontaneous abortions were noted in the group with high exposure to toluene (12.4 per 100 pregnancies) compared with those in the internal control group (2.9 per 100 pregnancies) and in the external control group (4.5 per 100 pregnancies). Among the exposed women, significant differences were also noted in the rates of spontaneous abortion before employment (2.9 per 100 pregnancies) and after employment in the factory (12.6 per 100 pregnancies). Almost all the women were nonsmokers and did not drink; other known risk factors such as maternal age at pregnancy, order of gravidity, and race were not likely to explain the results. Thus, specific exposure to toluene seems to be associated with a risk of foetal loss.     

Allergologic evaluation for workers exposed to toluene diisocyanate.

A cross-sectional investigation for allergology was performed of 15 painters exposed to high concentrations of toluene diisocyanate (TDI) (0.07-0.17 ppm) during the process of handling polyurethane varnish in a furniture manufacturing factory. Asthmatic reactions such as dyspnea, wheezing related to workshifts and contact dermatitis were observed in four and three cases respectively by questionnaire survey. Lung function tests on the painters showed significant decline in FEV1, %FEV1 and MMF compared to the referents. An increment in mast cell degranulation percentage could be seen in the painters. And also, patch testing with TDI were positive in five cases. From the results, it was suggested that both allergic pulmonary effects and contact sensitization had occurred in TDI-exposed painters in this factory.     

Mortality in a cohort of toluene exposed employees (rotogravure printing plant workers)

Since the beginning of the 1960s, toluene has been used as a solvent in all German rotogravure printing plants in a high degree of purity. These particular exposure conditions allow the investigation of the potential carcinogenicity of long-term toluene exposure. A historical cohort study was performed that included 6830 German men from 11 plants who were exposed to toluene from 1960 to 1992 in three work areas with different exposure levels. Overall, 466 deaths were observed, which provided a standardized mortality ratio (SMR) of 91.3 for overall mortality. A significantly decreased SMR for total mortality was seen in one of the three work areas (SMR = 67). Mortality from cancer did not differ substantially from the expected level, but in one of the work areas, mortality from cancers of the bone (Ninth Revision of the International Classification of Disease [ICD]-9 170; SMR = 813) and connective tissue (ICD-9 171; SMR = 631) was significantly elevated. In the entire cohort, mortality from lung cancer was increased by about 35% above total mortality, and by about 95% in one work area with low toluene exposure (not statistically confirmed). The SMR for death from alcohol dependence was statistically significantly increased (ICD-9 303; SMR = 314).     

Somatosensory evoked potentials in workers exposed to toluene and styrene.

Somatosensory evoked potentials (SEPs) were used to evaluate possible subclinical impairment of the nervous system due to occupational exposure to toluene and styrene. A group of 36 rotogravure printers with severe exposure to toluene, 20 workers with severe exposure to styrene in a glass laminate manufacturing plant, and a comparison group of healthy subjects were studied. The severity of exposure was documented by measurements of toluene and styrene concentrations in breathing zone air, by hippuric acid concentration in urine in the group exposed to toluene, and by urinary mandelic acid concentration in the group exposed to styrene. Somatosensory evoked potentials were measured by stimulation of the median nerve at the wrist and the tibial nerve at the ankle. Peripheral conduction velocities (CVs) in both extremities and central conduction time (CCT) after tibial nerve stimulation were significantly decreased in both exposed groups. Significantly prolonged latencies of peripheral and cortical SEPs to median nerve stimulation as well as cortical SEPs to tibial nerve stimulation were found in workers exposed to styrene. Some abnormalities in SEPs at peripheral or spinal and cortical levels were found in eight workers exposed to toluene and six workers exposed to styrene. Of these, in three workers exposed to toluene and two to styrene increased CCT and delayed latencies of cortical responses at normal conduction values in the periphery were found. A trend for increased frequency of abnormal SEPs with duration of exposure to toluene and styrene and alcohol abuse was found. Abnormalities in SEPs in the exposed groups are most probably of multifactorial origin. Central SEP abnormalities in both exposed groups could indicate early signs of subclinical dysfunction at spinal and cortical levels and could be due to toluene or styrene exposure probably potentiated by alcohol consumption in the group exposed to toluene.     

Hearing loss in workers exposed to toluene and noise

In this study we investigated the risk of hearing loss among workers exposed to both toluene and noise. We recruited 58 workers at an adhesive materials manufacturing plant who were exposured to both toluene and noise [78.6-87.1 A-weighted decibels; dB(A)], 58 workers exposed to noise only [83.5-90.1 dB(A)], and 58 administrative clerks [67.9-72.6 dB(A)] at the same company. We interviewed participants to obtain sociodemographic and employment information and performed physical examinations, including pure-tone audiometry tests between 0.5 and 6 kHz. A contracted laboratory certified by the Council of Labor in Taiwan conducted on-site toluene and noise exposure measurements. The prevalence of hearing loss of >or=25 dB in the toluene plus noise group (86.2%) was much greater than that in the noise-only group (44.8%) and the administrative clerks (5.0%) (p<0.001). The prevalence rates were 67.2, 32.8, and 8.3% (p<0.001), respectively, when 0.5 kHz was excluded from the estimation. Multivariate logistic regression analysis showed that the toluene plus noise group had an estimated risk for hearing loss>or=25 dB, 10.9 times higher than that of the noise-only group. The risk ratio dropped to 5.8 when 0.5 kHz was excluded from the risk estimation. Hearing impairment was greater for the pure-tone frequency of 1 kHz than for that of 2 kHz. However, the mean hearing threshold was the poorest for 6 kHz, and the least effect was observed for 2 kHz. Our results suggest that toluene exacerbates hearing loss in a noisy environment, with the main impact on the lower frequencies.     

甲苯对作业工人听力改变的调查

目的探讨甲苯对作业工人听力改变的影响.方法选择接触甲苯超标组(浓度＞100mg/m3)和未超标组(浓度＜100mg/m3)的作业工人各50名,对照组为不接触甲苯作业工人50名,进行纯音测定.结果超标组的甲苯浓度(264.42±36.99)mg/m3,未超标组甲苯的浓度(66.60±14.11)mg/m3;超标组发生听力异常率36%,对照组为4%,两组比较差异有显著性(P＜0.01),超标组与未超标组(16%)比较差异亦有显著性(P＜0.05);超标组听力异常出现的频率范围主要在2～6 kHz,并且听力下降率有随工龄增加而升高的趋势.结论职业性长期接触浓度超标甲苯对作业工人的听力可能有一定的影响.     

Mortality of workers exposed to toluene diisocyanate in the polyurethane foam industry.

OBJECTIVE: To evaluate cancer mortality among United States workers exposed to toluene diisocyanate (TDI) in the manufacture of polyurethane foam. METHODS: This cohort mortality study included 4611 men and women employed in four polyurethane foam plants for at least three months between the late 1950s and 1987. The mortality experience of the cohort was then compared with that of the general United States population. RESULTS: Current and past industrial hygiene data indicated that air concentrations in 1984-5 were below the current United States standard of 0.04 mg/m3 but exceeded the standard before 1980. Mortality ratio (SMR) 2.78, 95% confidence interval (95% CI) 0.57-8.13) and non-Hodgkin's lymphoma (SMR 1.54, 95% CI 0.42-3.95) were increased, but not significantly. There was one male breast cancer. However, breast cancer was not increased in women (SMR 0.74). No other cancer category had an increased number of deaths compared with the general population. Only non-Hodgkin's lymphoma and Hodgkin's disease showed a possible relation with time since first employment and no cancer death category showed a strong relation with duration of employment. Mortality from non-malignant respiratory disease was not increased (SMR 0.86). CONCLUSIONS: This young cohort has few deaths and short follow up. The findings are therefore not conclusive. Further years of follow up will enable better evaluation of mortality.     

Quantitative assessment of color vision impairment in workers exposed to toluene

Color vision was examined by the Lanthony-D-15 desaturated test in two groups of workers occupationally exposed to toluene and in a control group. Biological parameters of toluene exposure were analyzed: toluene in air and in venous blood, orthocresol, and hippuric acid in urine after workshift. The first exposed group, Group E₁, comprised 41 workers (toluene exposure ranged from 11.30 to 49.30 ppm), and the second exposed group, Group E₂, comprised 32 workers (toluene exposure ranged from 66.00 to 250.00 ppm). The nonexposed group, Group NE, comprised 83 subjects. Each group was divided into two subgroups; alcohol consumers and nonconsumers. Color vision loss was expressed as a color confusion index (CCI) and as age and alcohol intake-adjusted color confusion index (AACCI). Significantly higher values of CCI and AACCI (both P < 0.0001) in Group E₂ in comparison to Group NE, and significantly higher CCI (P < 0.0001) and AACCI (P < 0.05) values in Group E₂ in comparison to Group E₁ were established. The significant difference in CCI value between alcohol consumers and nonconsumers was established only in Group NE (P < 0.05). In Group NE significant correlation was found between CCI value as a dependent and age and alcohol intake as independent cofactors (R² = 0.45; P = 0.0000). In Group E₂ significant correlation was established between CCI as a dependent factor and age, toluene in air, and alcohol intake (R² = 0.72; P = 0.0001), or between CCI as dependent and age, toluene in blood and alcohol intake as independent cofactors (R² = 0.68; P = 0.0002). In Group E₁ significant correlation was established only between CCI and age (P < 0.005). In Group E_2, AACCI value significantly correlated with toluene in air (P < 0.0001), toluene in blood (r < 0.0005), orthocresol (P < 0.005) and hippuric acid (P < 0.005) in urine after workshift. There were no differences between smokers and nonsmokers in CCI values in the examined groups. Results of this study indicate that toluene in exposed workers can impair color vision. The role of alcohol intake and age influence on color vision loss cannot be ignored in such workers. Am. J. Ind. Med. 33:297–304, 1998. © 1998 Wiley-Liss, Inc.     

Adverse health effects in workers exposed to cadmium.

One hundred fifty-two workers who had been exposed to different levels of cadmium (Cd) absorption (blood Cd mean 16.34 micrograms/L, median 11.0 micrograms/L) in a factory making nickel-cadmium batteries were studied. A physical evaluation, as well as blood and urine cadmium and N-acetyl-beta-D-glucosaminidase (NAG), and other routine laboratory tests were performed in order to assess the relationship between different levels of exposure to occupational cadmium and potential cadmium-induced renal damage and other adverse health effects. We found significant correlation between levels of cadmium exposure and a selected group of symptoms and signs. The best predictor of this group of symptoms and signs was an indicator called internal dose index (Cd x exposure time). This indicator appears as the strongest, even after control by confounding factors, such as age and smoking. It is concluded that this index can be used for biological monitoring.     

Urinary levels of proteins and metabolites in workers exposed to toluene

We measured urinary excretion of albumin and retinol-binding proteins to investigate the occurrence of early renal dysfunction in 45 paint workers exposed principally to toluene, and in the same number of unexposed control subjects matched individually for sex and age. Two biological indicators of personal toluene absorption, namely urine hippuric acid and o-cresol, were also measured in the exposed subjects. A significantly higher level and increased prevalence of elevated retinol-binding protein in the urine of exposed workers was found, whereas no significant difference in urinary albumin concentration was seen between the two groups. Urinary concentrations of retinol-binding protein was correlated (r = 0.399, P less than 0.006) with that of o-cresol, but not with hippuric acid or employment duration. The results suggest a dose-dependent early tubular effect due to toluene exposure that might be useful for monitoring individuals exposed to toluene at work.     

Urinary levels of proteins and metabolites in workers exposed to toluene

Summary We measured urinary excretion of albumin and retinol-binding proteins to investigate the occurrence of early renal dysfunction in 45 paint workers exposed principally to toluene, and in the same number of unexposed control subjects matched individually for sex and age. Two biological indicators of personal toluene absorption, namely urine hippuric acid and o-cresol, were also measured in the exposed subjects. A significantly higher level and increased prevalence of elevated retinol-binding protein in the urine of exposed workers was found, whereas no significant difference in urinary albumin concentration was seen between the two groups. Urinary concentrations of retinol-binding protein was correlated (r = 0.399, P < 0.006) with that of o-cresol, but not with hippuric acid or employment duration. The results suggest a dose-dependent early tubular effect due to toluene exposure that might be useful for monitoring individuals exposed to toluene at work.     

Leukocyte agglutinins in workers exposed to benzene,toluene and xylene

Summary A leukoagglutination test and a cytotoxic test with leukocytes were performed on 76 workers exposed to occupational contact with benzene, toluene and xylene (52 men, 24 women); the possibility of contact with these substances was eliminated in 41 persons in the period directly preceding the examination, and blood samples were collected from 35 persons in the course of the exposure. In the first group the presence of leukocyte agglutinins for autologous leukocytes was found in only one person and in the second group in 10 persons. The increase of leukoagglutination titer of sera after their incubation with benzene, toluene or xylene was also demonstrated. This suggested the occurrence of allergic blood dyscrasia in some persons exposed to benzene and its homologues.