Solvent exposure in a shoe upper factory

Summary In a group of workers employed in a shoe upper factory, the concentrations of n-hexane, acetone, methylcyclopentane, 2-methylpentane, and 3-methylpentane were measured in environmental air, alveolar air and in blood. The data of methylcyclopentane, 2-methylpentane, and 3-methylpentane determination, as for n-hexane and acetone reported elsewhere, showed that alveolar and blood monitoring can replace environmental monitoring of solvents. In fact, it was found that alveolar and blood concentration, and lung uptake were correlated with environmental concentration of methylcyclopentane, 2-methylpentane, and 3-methylpentane.     

Solvent exposures at shoe factories and workshops in Hebron City, West Bank

Exposure to organic solvents has been reported to increase the risks for acute and chronic health effects among shoe industry workers. In developing countries, protection against chemical exposures is often not provided. The study was conducted to identify working conditions and estimate the concentrations of organic solvents used in shoe factories and workshops in Hebron City. Personal interviews containing questions related to personal protective equipment (PPE) were used to identify working conditions, and samples collected from factories and workshops were analyzed using gas chromatography. Geometric means (GMs) were calculated for the solvents. Six major organic solvents were detected in the factories. Acetone (GM = 51.5 mg/m3, GSD = 3.82) was common in gluing tasks. Dichloromethane (GM = 47 mg/m3, GSD = 2.62) was common in cleaning tasks. Heptane, methylethyl ketone, n-hexane, and toluene were common in gluing tasks. Four major organic solvents were detected in the workshops: acetone (GM = 32.3 mg/m:3, GSD = 6.33), toluene (GM = 70.3 mg/m3, GSD = 3.06), n-hexane (GM = 19.4 mg/m3:, GSD = 2.65), and methylethyl ketone (GM = 130 mg/mM3, GSD = 1.5). 81% of the factory workers had never used respiratory protective equipment, and 92% had never used work clothes. 97% of the workers in the workshops had never used respiratory protective equipment, 94% had never worn gloves, and 90% had never used work clothes. Exposures to solvents in the absence of personal Protective equipment, tasks barriers, and mechanical ventilation can adversely affect health.     

Urinary excretion of the metabolites of n-hexane and its isomers during occupational exposure.

Environmental exposure to commercial hexane (n-hexane, 2-methylpentane, and 3-methylpentane) was tested in several work places in five shoe factories by taking three grap-air samples during the afternoon shift. Individual exposure ranges were 32-500 mg/m3 for n-hexane, 11-250 mg/m3 for 2-methylpentane, and 10-204 mg/m3 for 3-methylpentane. The metabolites of commercial hexane in the urine of 41 workers were measured at the end of the work shift. 2-Hexanol, 2,5-hexanedione, 2,5-dimethylfuran, and gamma-valerolactone were found as n-hexane metabolites and 2-methyl-2-pentanol and 3-methyl-2-pentanol as 2-methylpentane and 3-methylpentane metabolites. The presence of metabolites in the urine was correlated with occupational exposure to solvents. n-Hexane exposure was correlated more positively with 2-hexanol and 2,5-hexanedione than with 2,5-dimethylfuran and gamma-valerolactone. A good correlation was also found between total n-hexane metabolites and n-hexane exposure. 2-Methyl-2-pentanol and 3-methyl-2-pentanol were highly correlated with 2-methylpentane and 3-methylpentane exposure. The results suggest that the urinary excretion of hexane metabolites may be used for monitoring occupational exposure to n-hexane and its isomers.     

Detailed exposure assessment for a molecular epidemiology study of benzene in two shoe factories in China

OBJECTIVES: We carried out a detailed exposure assessment of benzene and toluene in two shoe factories in Tianjin, China. Our goal was to identify workers with a broad range of benzene exposures, for an epidemiologic study relating exposure to early biologic effects. METHODS: A comprehensive exposure survey program was initiated. Over a period of 16 months, 2783 personal solvent exposure samples were collected in two workplaces from 250 workers. Mixed-effects models were used to identify factors affecting exposure. Principal component analyses (PCA) and subsequent regression analyses on the scores of the identified principal components were used to relate potential co-exposures to various exposure sources present in the workplace. RESULTS: The mean benzene exposure level was 21.86 p.p.m. (10th-90th percentiles 5.23-50.63 p.p.m.) in the smaller shoe factory (factory A) and 3.46 p.p.m. (10th-90th percentiles 0.20-7.00 p.p.m.) in the larger shoe factory (factory B). Within-factory exposure levels differed among job titles and were higher for subjects directly involved in handling glues. In contrast, mean toluene levels were relatively similar in the two factories (factory A, 9.52 p.p.m.; factory B, 15.88 p.p.m.). A seasonal trend was identified for both benzene and toluene in factory B. This could be explained in part by changes in air movement and ventilation patterns occurring during the year. A seasonal trend was not present in the smaller shoe factory, where general ventilation was absent. Supplemental analysis showed that exposure levels to other hydrocarbons were low (< or =5 p.p.m.), less than 5% of their respective ACGIH threshold limit values, and generally comparable in the two factories. PCA showed that co-exposures in factory B could largely be explained by glue sources that were used in distinct areas in the workplace. CONCLUSIONS: We demonstrated the occurrence of a broad range of benzene exposure levels in two shoe manufacturing factories in Tianjin, China. Benzene and toluene exposures were determined in part by the degree of contact with glues, the benzene and toluene content of each glue, air movement and ventilation patterns. The availability of long-term monthly personal monitoring data provides an excellent opportunity to estimate individual exposures at different times during the 1 yr period of observation.     

Shoe-makers'' polyneuropathy in Italy: the aetiological problem.

Since 1957, when the first cases of the so-called shoe-makers' toxic polyneuropathy were reported, nearly 400 cases have been described in the Italian literature. The substance that was considered to be responsible for the disease was triorthocresylphosphate (TOCP) contained in glues, artificial leathers, and some types of paints. However numerous chemical analyses of glues and leathers taken from factories where cases of the disease occurred have shown that in almost all instances little or no TOCP was present. In addition the disease manifests itself more frequently during winter and spring and this is not consistent with the absorption of the causative agent through the skin and/or gastrointestinal tract. In order to clarify the aetiology of the disease 122 workers in the shoe industry affected by toxic polymeuropathy during the period 1971-74 were studied. Workplaces where cases of polyneuropathy had occurred were visited and samples of glues and solvents were taken for chemical analysis. The polyneuropathy chiefly affects workers engaged in glueing and in the cleaning process, but it also affects those who do not have direct contact with glues or solvents. The disease is more common in women (68%) than in men (32%) and, in its more severe form begins with overwhelming prevalence during winter and early spring regardless of the job performed. No direct relationship has been found between the severity of the disease and the number of years of work in the shoe industry or of specific exposure (that is the number of years of work in the activity performed at the onset of the disease). The polyneuropathy is found almost exclusively among workers of the artisam type in small shoe factories, where standards of hygiene are low. Chemical analysis of glues and cleaning fluids collected from five different factories, where 20 cases of polyneuropathy occurred, showed the presence of paraffin hydrocarbons with a low boiling point (pentane, 2-methyl-pentane, 3-methyl-pentane, n-hexane, etc.) in concentrations of more than 80% by weight.     

Shoe-makers' polyneuropathy in Italy: the aetiological problem.

Since 1957, when the first cases of the so-called shoe-makers' toxic polyneuropathy were reported, nearly 400 cases have been described in the Italian literature. The substance that was considered to be responsible for the disease was triorthocresylphosphate (TOCP) contained in glues, artificial leathers, and some types of paints. However numerous chemical analyses of glues and leathers taken from factories where cases of the disease occurred have shown that in almost all instances little or no TOCP was present. In addition the disease manifests itself more frequently during winter and spring and this is not consistent with the absorption of the causative agent through the skin and/or gastrointestinal tract. In order to clarify the aetiology of the disease 122 workers in the shoe industry affected by toxic polymeuropathy during the period 1971-74 were studied. Workplaces where cases of polyneuropathy had occurred were visited and samples of glues and solvents were taken for chemical analysis. The polyneuropathy chiefly affects workers engaged in glueing and in the cleaning process, but it also affects those who do not have direct contact with glues or solvents. The disease is more common in women (68%) than in men (32%) and, in its more severe form begins with overwhelming prevalence during winter and early spring regardless of the job performed. No direct relationship has been found between the severity of the disease and the number of years of work in the shoe industry or of specific exposure (that is the number of years of work in the activity performed at the onset of the disease). The polyneuropathy is found almost exclusively among workers of the artisam type in small shoe factories, where standards of hygiene are low. Chemical analysis of glues and cleaning fluids collected from five different factories, where 20 cases of polyneuropathy occurred, showed the presence of paraffin hydrocarbons with a low boiling point (pentane, 2-methyl-pentane, 3-methyl-pentane, n-hexane, etc.) in concentrations of more than 80% by weight.     

Shoe manufacturing and solvent exposure in northern Portugal

Shoe manufacturing is a traditional industry in northern Portugal. There are nearly 1500 factories that employ about 54,000 workers. Among the materials used in the shoe manufacturing process, that could be occupational hazards, are the adhesives, especially adhesives solutions based on organic solvents. The National Institute of Health (Oporto Branch) carried out a study of 100 factories in northern Portugal to study solvent exposure in shoe manufacturing. The surveyed population, (4615 workers) was young (mean age = 33 years; range = 18-45) and predominantly female (68.5%). The results from the air samples analyses show 20 different organic compounds existing in the workplaces. The more common compounds found were n-hexane, toluene, and acetone. The results of the study show that in 53.7 percent of the factories there are operations where the solvent exposure is significant and represents a health hazard to the workers. These operations are mainly gluing, waxing, and polishing stations. Occupational risk of exposure to solvents concerned 44.2 percent of the workers. This study points out the existence of inadequate ventilation in the workplaces and inappropriate personal protective equipment to prevent dermatitis risk from adhesives, wax, and polish. The organic solvents present in workplaces also increase fire risk.     

An outbreak of N-hexane induced polyneuropathy among press proofing workers in Taipei

The objective of this study was to determine the prevalence and the etiology of polyneuropathy observed among press proofing workers in Taipei. Neurological examinations of 59 workers, from 16 press proofing factories, were conducted. Fifty-four of those workers subsequently underwent studies of nerve conduction velocities. Samples of bulk solvent from the involved factories were analyzed for their contents using gas chromatography. Fifteen (25%) of the study group were found to have polyneuropathy. All 15 patients with polyneuropathy were from factories in which solvents containing n-hexane were regularly used, and there was a significant association between n-hexane concentration in the bulk samples and prevalence of polyneuropathy. The air concentration of n-hexane in one factory in which all six employees developed polyneuropathy was 190 ppm. Workers who were exposed to n-hexane at air levels of less than 100 ppm but who frequently worked overtime showed a significant slowing of motor nerve conduction velocities on median, ulnar, and peroneal nerves. Of 13 workers who regularly slept in the factory, 12 (92%) had polyneuropathy compared to three (7%) of 46 workers who did not sleep in the factory. The outbreak of polyneuropathy was attributed to a combination of the use of solvents with high contents of n-hexane, poor ventilation, and the practice of sleeping in the factories between shifts.     

大型制鞋和电子行业有机溶剂职业危害和防护措施分析

目的分析大型制鞋和电子行业有机溶剂危害及防控措施。方法利用职业卫生调查、职业病危害因素检测等方法识别和检测各岗位有机溶剂暴露情况,并对各岗位采取的职业病防护措施进行分析。结果制鞋企业有机溶剂为苯、甲苯、二甲苯、正己烷、丙酮、丁酮、环己酮、乙酸乙酯,电子企业接触的有机溶剂为苯、二甲苯、正己烷、丙酮、乙酸乙酯、乙醇、甲醇和异丙醇等。通过低毒代替高毒,局部抽排风等工艺、工程和管理措施,除制鞋企业贴底处理岗位丁酮8 h时间加权平均浓度(CTWA)为302.13 mg/m3和配料房配料岗位乙酸乙酯短时间接触浓度(CSTEL)为378.5 mg/m3外,其余岗位职业病危害因素均低于职业接触限值。结论大型制鞋和电子行业有机溶剂危害可通过工艺措施、工程措施、个人防护措施和管理措施进行有效防护。     

2,5-Hexanedione excretion after occupational exposure to n-hexane

The urinary excretion of the n-hexane metabolite 2,5-hexanedione (HD) was determined in four shoe factory workers during four workingdays that were preceded by four free days and followed by two free days. The correlation between excretion of HD and the n-hexane concentrations in the workroom air was evaluated. The air concentrations of n-hexane and those of acetone, toluene, and other organic solvents were monitored with charcoal tubes. All the urine from each worker was collected at freely chosen intervals during the experimental period and the following two free days. The samples were analysed by gas chromatography. The relative excretion of HD increased as the exposure to n-hexane increased, although it seemed that HD accumulated progressively in the body at the highest n-hexane concentrations and at higher total solvent concentrations.     

2,5-Hexanedione excretion after occupational exposure to n-hexane.

The urinary excretion of the n-hexane metabolite 2,5-hexanedione (HD) was determined in four shoe factory workers during four workingdays that were preceded by four free days and followed by two free days. The correlation between excretion of HD and the n-hexane concentrations in the workroom air was evaluated. The air concentrations of n-hexane and those of acetone, toluene, and other organic solvents were monitored with charcoal tubes. All the urine from each worker was collected at freely chosen intervals during the experimental period and the following two free days. The samples were analysed by gas chromatography. The relative excretion of HD increased as the exposure to n-hexane increased, although it seemed that HD accumulated progressively in the body at the highest n-hexane concentrations and at higher total solvent concentrations.     

Prevalence of self-reported health complaints among shoe workers of small workshop exposed to organic solvents in Hebron City, West Bank: a cross-sectional survey

The study was conducted to estimate the prevalences of neurological disorders and mucous membrane irritation complaints among workers of shoe workshops in Hebron City, in particular to measure the associations between the occurrence of symptoms indicating polyneuropathy among workers and exposure to organic solvents in the glueing tasks. A group of 103 male workers from 30 workshops, exposed to organic solvents for more than one year were recruited to the study during the years 1996-1997. A validated Swedish neuropsychiatric questionnaire which contained questions on neurological and mucous irritation symptoms was used. Prevalence ratios were used as an indicator for relative risk. The overall prevalence of painful tingling of limbs (used as indicator of polyneuropathy) was high among the workshop workers (40%) and was significantly associated with long term exposure to organic solvents in glueing tasks (PR 2.8: 95% CI 1.0-8.3). Moderate associations were seen in other tasks. Headache and mental irritability did not show any association with organic solvent exposure in the workshop tasks. Breathing difficulty showed a moderate non-significant association with long term exposure to organic solvents (72 months) in cleaning tasks (1.9,0.7-4.8), while sore eyes also showed a moderate non-significant association with exposure to organic solvents for 25-72 months in the glueing tasks. Long term exposure to n-hexane (mainly found in the glues) could be the main cause of polyneuropathy among the workers of Hebron shoe workshops. The absence of effective ventilation systems and personal protective equipment might increase the prevalence of polyneuropathy among these workers. In conclusion, glues containing high concentrations of n-hexane are still in use in many shoe workshops in Hebron City (as well as in other developing countries), and long term exposure to n-hexane in glueing compounds could result in polyneuropathy among the workers. However, in the absence of objective measurements our results must be interpreted with caution. Well planned longitudinal studies with objective measures of exposure and disease are important for future research in developing countries.     

Solvent Exposures at Shoe Factories and Workshops in Hebron City,West Bank

Abstract

Exposure to organic solvents has been reported to increase the risks for acute and chronic health effects among shoe industry workers. In developing countries, protection against chemical exposures is often not provided. The study was conducted to identify working conditions and estimate the concentrations of organic solvents used in shoe factories and workshops in Hebron City. Personal interviews containing questions related to personal protective equipment (PPE) were used to identify working conditions, and samples collected from factories and workshops were analyzed using gas chromatography. Geometric means (GMs) were calculated for the solvents. Six major organic solvents were detected in the factories. Acetone (GM = 51.5 mg/m³, GSD = 3.82) was common in gluing tasks. Dichloromethane (GM = 47 mg/m³, GSD = 2.62) was common in cleaning tasks. Heptane, methylethyl ketone, n-hexane, and toluene were common in gluing tasks. Four major organic solvents were detected in the workshops: acetone (GM = 32.3 mg/m³, GSD = 6.33), toluene (GM = 70.3 mg/m³, GSD = 3.06), nhexane (GM = 19.4 mg/m³, GSD = 2.65), and methylethyl ketone (GM = 130 mg/m³, GSD = 1.5). 81% of the factory workers had never used respiratory protective equipment, and 92% had never used work clothes. 97% of the workers in the workshops had never used respiratory protective equipment, 94% had never worn gloves, and 90% had never used work clothes. Exposures to solvents in the absence of personal Protective equipment, tasks barriers, and mechanical ventilation can adversely affect health.     

Sister chromatid exchanges and micronuclei in peripheral lymphocytes of shoe factory workers exposed to solvents

We examined sister chromatid exchanges (SCEs) and micronuclei (MN; cytokinesis-block method) in cultured peripheral lymphocytes from 52 female workers of two shoe factories and from 36 unexposed age- and sex-matched referents. The factory workers showed an elevated level of urinary hippuric acid, a biomarker of toluene exposure, and workplace air contained high concentrations of various organic solvents such as toluene, gasoline, acetone, and (in one of the plants only) ethylacetate and methylenediphenyl diisocyanate. The shoe factory workers showed a statistically significant higher frequency of micronucleated binucleate lymphocytes in comparison with the referents. This finding agreed with three preliminary MN determinations (each comprising 27-32 shoe workers and 16-20 controls) performed in one of the plants 2-5 years earlier. The shoe factory workers also had a lower average level of blood hemoglobin than the referents. In contrast, no difference was found between the groups in SCE analysis. Smokers showed significantly higher mean frequencies of SCEs per cell and high frequency cells (HFC) than nonsmokers. Aging was associated with increased MN rates and reduced cell proliferation. Polymorphism of the glutathione S-transferase M1 gene (GSTM1) did not affect the individual level of SCEs; but in smoking shoe workers an effect of the occupational exposure on the frequency of micronucleated cells could be seen only in GSTM1 null subjects. The low prevalence of the glutathione S-transferase T1 (GSTT1) null genotype precluded the evaluation of the influence of GSTT1 polymorphism. Our results show that the shoe factory workers have experienced genotoxic exposure, which is manifest as an increase in the frequency of MN, but not of SCEs, in peripheral lymphocytes. The exposures responsible for the MN induction could not be identified with certainty, but exposure to benzene in gasoline and methylenediphenyl diisocyanate may explain some of the findings.     

34份有机溶剂中正己烷及三氯乙烯检测结果分析

目的:了解有机溶剂中正己烷及三氯乙烯的含量,为职业卫生的监督监护提供科学依据。方法:用气相色谱法测定34份有机溶剂中正己烷和三氯乙烯的含量。结果:共检测34份有机溶剂,其中检出正己烷34份,检出率为100%;检出三氯乙烯28份,检出率为82.35%。结论:有机溶剂中大多数存在对人体有害的物质,应用该类产品的单位在使用前应先进行检测再选用合适的产品,有关部门应重视对使用该类产品企业的监督监测工作。     

惠州市有机溶剂职业危害现状调查及防治对策

目的了解惠州市使用有机溶剂企业的职业危害现状,为有效开展有机溶剂的职业病危害防治提供依据。方法对使用有机溶剂的企业进行职业病危害状况调查,并对工作场所空气中有机溶剂浓度进行检测。结果工业企业工作场所中有机溶剂种类较多,主要有苯、甲苯、二甲苯、苯乙烯、正己烷、丙酮、丁酮、二氯乙烷、二氯甲烷、三氯乙烯等,工作场所空气中有机溶剂检测点的合格率为85.1%。部分工业企业法制意识淡薄,职业卫生管理制度及防护措施不够健全。结论有机溶剂职业病危害状况不容乐观,应重点加强使用有机溶剂行业及接触有机溶剂作业岗位的职业病危害防治工作,建立有效的职业病危害监管机制。     

Does n-heptane cause peripheral neurotoxicity? A case report in a shoemaker

Subjective and electrophysiological signs relating to the centraland peripheral nervous systems developed in a shoemaker, a fewmonths after beginning work at home. Signs of central nervoussystem involvement rapidly disappeared after the end of theexposure, whereas those of mild peripheral neuropathy lastedfor several months. The glue used contained a variety of solventsincluding ethylacetate, cyclohexane, methylcyclohexane, methylethylketoneand others; n-hexane was not detected, whereas, unusually, n-heptanewas. This exposure was reproduced experimentally in the samework room and the solvent air level did not exceed the AmericanConference of Governmental Industrial Hygienists threshold values.A tentative conclusion is that the toxic effects on the peripheralnerve are likely to be due to n-heptane.     

The urinary concentration of solvents as a biological indicator of exposure: proposal for the biological equivalent exposure limit for nine solvents

Organic solvents are generally volatile substances that are absorbed mainly through the lungs; they are eliminated chiefly through the lungs and kidneys. In urine they are present as metabolites and, in very little part, as parent compound. The urinary concentration of solvent (Cu) can be used for the biological monitoring of exposed subjects to evaluate their exposure and correlate with the Threshold Limit Value (TLV) during the working day. The authors report some results obtained with workers occupationally exposed to solvents. The results concern the correlation between urinary concentration (Cu, micrograms/L) vs. average environmental concentration (Ci, mg/m3) measured in the breathing zone. For each solvent studied (acetone, 2-cyclohexane, 1,2-dichloropropane, n-hexane, methyl ethyl ketone, perchloroethylene, styrene, toluene, 1,1,1-trichloroethane) the authors propose a Biological Equivalent Exposure Limit (BEEL) corresponding to the environmental TLV.     

Adsorption and desorption of organic solvent vapours using silica gel (author's transl)

For a simple analysis of organic solvent vapours in working environmental air, we investigated the following method. First, join the adsorption tube (2 ml of 60--80 mesh silica gel packed in a 5 mm phi x 18 cm glass tube) to hand vacuum pump and suck 200 ml of the sample air. After adsorption, join this adsorption tube to the sampling bottle under reduced pressure. Second, open the cock of the sampling bottle and heat only the adsorption tube in an oven for 3 min. In the operation mentioned above, organic solvent vapours desorbed from the silica gel transfer smoothly into the sampling bottle. After desorption, take 1 ml of air from the sampling bottle and determine the sample quantities with the gas chromatograph. Sample solvents used were as follows: n-hexane, cyclohexane, benzene, toluene, m-xylene, styrene, 1.1.1-trichloroethane, dichloromethane, tetrachloroethylene, ethylacetate, acetone, methyl-ethylketone, methylisobutylketone, methanol, ethanol, n-propanol, and n-butanol. We obtained the following results. (1) 60--80 mesh silica gel is appropriate for this method. (2) Heating temperature to get 100% recovery varies with the type of organic solvent. m-Xylene and styrene require 250 degrees C, methylisobutylketone and n-butanol 200 degrees C, and the others 150 degrees C. (3) If the adsorption tube is preserved in a freezer at -20 degrees C, no decrease is observed for up to 7 days. At room temperatures, however, 1.1.1-trichloroethane, dichloromethane, tetrachloroethylene, n-hexane, and cyclohexane decreased by the amount 4-10% in the tube for each 24-hour period. These sample should be preserved at lower temperatures soon after absorbing on the silica gel. This method is simple and accurate, so valid for analysis of organic solvent vapours in the working environmental air.     

Respiratory retention,uptake and excretion of organic solvents in man

Summary Mechanisms of respiratory retention of organic solvents are discussed. Respiratory retention, uptake and excretion were estimated separately in 66 men and women volunteer students exposed to benzene, toluene, n-hexane, trichloroethylene, acetone, ethyl acetate and ethyl alcohol.After 2 hrs exposure, respiratory retention reached constant levels; these differed for each of the 7 organic solvents tested. No sex difference in retention was observed. Respiratory excretion values differed as 100 × concentration in expired air immediately following breathing of solvent free air/concentration of solvent in air breathed during exposure. Men excreted more toluene and trichloroethylene than did women. Uptake varied 27–60%.These results were presented in part before the 16th International Congress on Occupational Health, September 25th, 1969, Tokyo.