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.     

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.     

某鞋厂347例接触混合有机溶剂作业工人肝脏B超检查结果分析

目的 探讨长期低浓度接触混合有机溶剂对制鞋作业工人肝脏的影响。 方法 对生产车间使用甲苯、苯、二氯乙烷、正己烷等混合有机溶剂的某鞋业工厂347名工人(接触组)和工厂无毒物接触史后勤人员321人(对照组)进行肝脏B超检查,比较两组检查结果。 结果 生产车间使用的有机溶剂的时间加权平均浓度均未超过职业接触限值。接触组弥漫性肝回声音改变、肝大的检出率均高于对照组,上述指标在两组间比较,差异均有统计学意义(χ2=27.8、12.5,P<0.05)。将两组各分成6个工龄段,弥漫性肝回声改变的检出率在工龄大于等于2年(4个工龄段)的两组员工间比较,差异均有统计学意义(χ2=8.9、10.2、10.2、10.5,P<0.05),两组的异常检出率均随着工龄的增加而升高。 结论 较长时间接触混合有机溶剂对作业工人肝脏可能存在慢性损害,应注意预防。     

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.     

Solvent pollution in shoe factories]

In order to study solvent exposure in shoe factories, 43 kinds of glues and 22 solvent products used in footwear manufacturing were analyzed. A gas chromatographic spectrometric method was used to identify the mixtures of solvents contained in glues and their diluents. Acetone, ethylacetate and cyclohexane were the solvents more frequently found in glues. Cyclohexane represented on average about 40% of the solvent mixture. Methyl ethyl ketone, 3-methylpentane and 2-methylpentane were often present in glues (45-52% of the samples), but only in a few cases were they associated with n-hexane. N-hexane and methylcyclopentane were found in 32% of the glue samples. N-hexane represented 47% of the solvents only in one glue. Most of the glues contained less than 10% n-hexane. Other solvents (dichloropropane, toluene, trichloroethane, butyl acetate, iso-butyl acetate and 2,2-dimethylbutane) were found in few glue samples or in low percentages. The 22 solvents used as glue diluents were mainly acetone, ethylacetate, dichloromethane and methyl ethyl ketone. The results suggest that solvent exposure in shoe factories has changed compared with data reported about 10 years ago. Biological monitoring of shoe factory workers should measure exposures to the specific solvents found in each factory, especially acetone, cyclohexane, ethylacetate and methyl ethyl ketone.     

Occupational exposure to mixtures of organic solvents increases the risk of neurological symptoms among printing workers in Hong Kong

LEARNING OBJECTIVES: Summarize the nature and extent of exposure to organic solvents to which printing workers in this study were subjected. Compare the numbers of neurological symptoms in exposed and non-exposed workers and how they related to level of exposure, as defined by specific job title or by air sampling. Clarify the relationship between exposure to organic solvents and individual psychoneurological and other symptoms. ABSTRACT: The health effects of low-dose occupational exposure to organic solvents remains unclear. A cross-sectional survey was conducted among 762 male printing workers to assess the impacts of exposure to mixtures of n-hexane, toluene, isopropyl alcohol, and benzene on neurological and other symptoms. After controlling for age, smoking, alcohol drinking, past exposure history, working hours and shift work, current exposure to solvent mixtures was significantly associated with the total number of neurological symptoms and with the prevalence of specific symptoms of the nervous system and mucous membrane irritation. The adjusted odds ratio of neurovegetative lability (1.7-5.9), abnormal or reduced smell (1.6-4.1), memory loss (1.8), and mucous membrane irritation symptoms (1.5-4.6) significantly increased in the exposed group, especially when the summation index of exposure exceeded one.     

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.     

Cancer mortality among shoe manufacturing workers: an analysis of two cohorts.

OBJECTIVES: To examine the cancer risk of shoe manufacturing workers and evaluate whether the risk was associated with exposure to leather dust and solvents. METHODS: Data from two historical cohort studies of shoe workers were expanded and analysed in parallel. A total of 4215 shoemakers from England contributing 103 726 person-years at risk and 2008 shoemakers from Florence, Italy, contributing 54,395 person-years at risk were included in the analysis. Exposure to leather dusts and solvents from glues was evaluated on the basis of job title information. Standardised mortality ratios (SMR) were calculated as ratios of observed deaths (Obs) over expected derived from national mortalities. RESULTS: Overall mortality was lower than expected in both cohorts (English cohort: Obs 3314, SMR 81, 95% confidence interval (95% CI) 78-84; Florence cohort: Obs 333, SMR 87, 95% CI 78-97). An increased risk of nasal cancer was found (English cohort: Obs 12, SMR 741; Florence cohort: Obs 1, SMR 909). 10 of the 13 cases occurred among English workers employed in the manufacture of welted boots (SMR 926, 95% CI 444-1703), a sector of the industry thought to have had the highest exposure to leather dust. Mortality from leukaemia was not increased in the English cohort (Obs 16, SMR 89), but was increased in the Florence cohort (Obs 8, SMR 214, 95% CI 92-421); and the highest risk was found among shoe workers in Florence who were first exposed between 1950 and 1959 when exposure to benzene was substantial (Obs 3, SMR 536, 95% CI 111-1566). Some evidence for an excess risk of stomach, bladder, and kidney cancer, as well as multiple myeloma and non-Hodgkin's lymphoma was also found in the Florence cohort only among workers employed in jobs with the highest exposure to solvents. CONCLUSIONS: These findings confirm the associations between exposure to leather dust and nasal cancer and between exposure to benzene and leukaemia in the shoe manufacturing industry and suggest that the risk of other cancers may be increased among workers exposed to solvents or glues.     

Effects of exposure to organic solvents on menstrual cycle length.

To investigate the association between organic solvent exposure and menstrual disturbance, we conducted a cross-sectional study among 1408 petrochemical workers in China. Based on an industrial hygiene evaluation, we classified the workshops according to the presence or absence of organic solvents (benzene, styrene, toluene, or xylene). We used logistic regression to estimate odds ratios and 95% confidence intervals for prolonged menstrual cycle length (oligomenorrhea: average cycle length > 35 days during the previous year) associated with the exposure. After adjustment for confounders, each additional year of work in an exposed workshop was associated with a 7% increase in oligomenorrhea (odds ratio, 1.07; 95% confidence interval, 1.00 to 1.14). Compared with no exposure, 3 or more years of exposure was associated with a 53% increase in oligomenorrhea (odds ratio, 1.53; 95% confidence interval, 1.00 to 2.34). We concluded that exposure to organic solvents is associated with a trend toward increased frequency of oligomenorrhea.     

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.     

Prevalence of neuropsychiatric and mucous membrane irritation complaints among Palestinian shoe factory workers exposed to organic solvents and plastic compounds

BACKGROUND: Long-term exposure to organic solvents is associated with neuropsychiatric and mucus membrane irritation. In developing countries, efforts to secure a good working environment are inadequate and protection against chemical exposures is often neglected. METHODS: In a cross-sectional survey, the prevalence of self-reported health complaints and the association with long-term exposure to solvents and plastic materials in the work environment was studied among 167 shoe-factory workers. Prevalences and adjusted prevalence ratios (PR)were calculated in Cox regression. 95% confidence intervals were estimated for PRs of adverse health effects. RESULTS: Overall, the workers reported high prevalences of neuropsychiatric and mucus membrane complaints: headache (65%), mental irritability (53%), tingling of limbs (46%), and sore eyes (43%). Cleaning work was associated with tingling of limbs (PR = 1.8, 1.0-3.2), sore eyes (PR = 1.9, 1.1-3.3), and breathing difficulty (PR = 2.0, 1.0-3.9); plastic work was associated with tingling of limbs (PR = 1.8, 1.2-2.9)and sore eyes (PR = 1.7, 1.1-2.7); and varnishing was associated with breathing difficulty (PR = 1.9, 1.1-3.5). CONCLUSIONS: The high prevalence of self-reported health complaints and the exposure-outcome association could be due to volatile organic solvents (dichloromethane, n-hexane)and plastic compounds (isocyanates and polyvinyl chloride). Absence of a satisfactory work environment is likely to contribute to high exposure levels.     

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.     

Relationship between clinical and electromyographic findings and exposure to solvents, in shoe and leather workers

A very high prevalence of polyneuropathy was observed in shoe and leather workers from the area of Florence. In addition, normal workers showed abnormally low maximal nerve motor conduction velocity. A linear decrease of motor conduction velocity was observed as a function of age and of the length of exposure to solvents. The worker population showed a steeper decrease with age than controls. A higher prevalence of polyneuropathy was observed when the amount of glue used by each worker per day was higher, and when the air volume of the plant was smaller. The subjective symptoms most frequently associated with polyneuropathy were muscle spasms, leg weakness and pain, and arm paresthesiae. Cases of polyneuropathy were more frequent in the workers exposed to solvents and in the older age group. A solvent aetiology of the disease is suggested, and glue substitution and proper hygienic conditions are recommended.     

Relationship between clinical and electromyographic findings and exposure to solvents, in shoe and leather workers.

A very high prevalence of polyneuropathy was observed in shoe and leather workers from the area of Florence. In addition, normal workers showed abnormally low maximal nerve motor conduction velocity. A linear decrease of motor conduction velocity was observed as a function of age and of the length of exposure to solvents. The worker population showed a steeper decrease with age than controls. A higher prevalence of polyneuropathy was observed when the amount of glue used by each worker per day was higher, and when the air volume of the plant was smaller. The subjective symptoms most frequently associated with polyneuropathy were muscle spasms, leg weakness and pain, and arm paresthesiae. Cases of polyneuropathy were more frequent in the workers exposed to solvents and in the older age group. A solvent aetiology of the disease is suggested, and glue substitution and proper hygienic conditions are recommended.     

Prenarcotic and neuraesthenic symptoms among Dutch workers exposed to organic solvents

A population of 379 Dutch workers exposed to organic solvents was compared with a non-exposed population of 443 workers with regard to the prevalence of prenarcotic and neuraesthenic symptoms. Participants completed a questionnaire to collect information about their occupational history, exposure to organic solvents, and the occurrence of symptoms. The results of the study indicated that workers exposed to solvents have a higher reporting rate of prenarcotic symptoms than workers not exposed to solvents. The prevalence of chronic neurotoxic effects, however, in the form of neuraesthenic symptoms was only weakly associated with reported exposure to organic solvents. The influence of work stress in the development of these symptoms is perhaps more important than the role of exposure to organic solvents. It is concluded that the organic solvent syndrome type I, as defined by an international workshop, is not an important health hazard among Dutch painters.     

Prenarcotic and neuraesthenic symptoms among Dutch workers exposed to organic solvents.

A population of 379 Dutch workers exposed to organic solvents was compared with a non-exposed population of 443 workers with regard to the prevalence of prenarcotic and neuraesthenic symptoms. Participants completed a questionnaire to collect information about their occupational history, exposure to organic solvents, and the occurrence of symptoms. The results of the study indicated that workers exposed to solvents have a higher reporting rate of prenarcotic symptoms than workers not exposed to solvents. The prevalence of chronic neurotoxic effects, however, in the form of neuraesthenic symptoms was only weakly associated with reported exposure to organic solvents. The influence of work stress in the development of these symptoms is perhaps more important than the role of exposure to organic solvents. It is concluded that the organic solvent syndrome type I, as defined by an international workshop, is not an important health hazard among Dutch painters.     

Impairment of colour vision in patients with n-hexane exposure-dependent toxic polyneuropathy

The aim of this study was to investigate the effects of n-hexane on visual function and to determine the duration of any symptoms related to workplace exposure. The study involved 26 workers diagnosed as having polyneuropathy following n-hexane exposure. The FM-100 Hue test was used to determine colour discrimination in study volunteers. Their results were compared with a control group of 50 people who had not been exposed to n-hexane. The mean total error score for the exposed group was 168.3 (SD = 70.5) for the right eye and 181.5 (SD = 103.0) for the left eye. The mean total error scores for the control group for the right and left eyes were 36.0 (SD = 19.8) and 35.6 (SD = 18.2), respectively. Differences between total and partial error scores for exposed and control groups were statistically significant (P < 0.001). These results may indicate a relationship between n-hexane exposure and development of defects in colour vision, and would support a recommendation for periodic assessment of workers exposed to n-hexane and chemically related solvents.