Occupational Exposure to Benzene Among Shoemakers And Others - Research Paper Example

?Table of Contents Introduction………………………………………………………………………… 2 2. Body 2 Benzene overview……………………………………………………….. 3 2.2. Benzene impact on health……………………………………………….. 3 2.3. Supporting studies……………………………………………………….. 5 3. Conclusion…………………………………………………………………………. 14 References……………………………………………………………………………. 15 Occupational Exposure to Benzene among shoemakers and others 1. Introduction Occupational hazards are just one of the issues which employees often face in the workplace. These hazards are often dangerous to their health and well-being, however, out of an economic necessity, they have to endure and often expose themselves to these risks. There are different kinds of occupational hazards, and these are mostly found in heavy or manual work, however, they are also found in lighter office or clerical work. Construction workers are often exposed to the hazards of heavy machinery use, office workers are at risk for carpal tunnel syndrome, and health workers are often exposed to contamination. Among shoemakers, benzene is an occupational risk. Benzene is often used by shoemakers in the shoemaking process and it is a chemical compound which has elements harmful to a person’s health. 1.1 Statement of the Problem: This paper shall discuss the occupational exposure to Benzene among shoemakers and other individuals using said compound. This discussion shall first discuss the qualities of benzene in general and its elements which imply its health risks. Secondly, various studies discussing the impact of benzene on the health of workers shall be individually presented. Lastly, a summary and concluding remarks shall be indicates at the end of this article. 1.2 Significance of the problem This paper is being carried out in order to establish a comprehensive and an analytical discussion of the health impact of benzene on workers. It is also being carried out in order to establish a basis for employers and other managers on the establishment of remedies to prevent these hazards or to at least reduce the health impact of this chemical compound. 2. Benzene overview Benzene is considered an organic chemical compound made up of six carbon atoms joined together in a ring, having one hydrogen atom attached to each carbon atom (Lide, 2005). It is considered in the same category as the hydrocarbons which have long been considered toxic to our environment. Benzene is a natural ingredient in crude oil and also considered a petrochemical (Lide, 2005). It is aromatic, colorless, and highly flammable. It is often utilized as a precursor to heavy chemicals like ethylbenzene and cumene (Arnold, et.al., 1958). It has a high octane number, and as such is a major component of gasoline. 2.1 Benzene health risks Benzene increases health risks for acquiring cancer and other diseases. It has been known to cause leukemia because of its negative impact on the bone marrow (Smith, 2010). Based on epidemiological and clinical studies, it has been known to cause aplastic anemia, acute leukemia, and other diseases where affectations of the bone marrow are concerned. Specific blood malignancies indicate that benzene is linked to diseases like acute myeloid leukemia (AML), myleodysplastic syndrome, acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML) (Smith, 2010). As early as 1948, the American Petroleum Institute stated that benzene is a very dangerous compound; the US Department of Health and Human Services has also labeled the compound as a carcinogen and long-term exposure to high levels of this compound in the atmosphere has been known to cause leukemia (American Petroleum Institute, 1948). Moreover, it has long been proven and undisputed that benzene has been known to cause AML and acute non-lymphocytic leukemia. The exposure of humans to this compound is considered a widespread issue. Scientists explain that benzene targets the liver, lungs, kidneys, the bone marrow, the heart, the brain, and even the DNA where breaks are seen and chromosomes have been damaged (Huff, 2007). Benzene also impacts on cancer in animals, and for humans, both genders have had similar issues with the compound (Huff, 2007). Women exposed to high levels of this compound have expressed issues with irregular menstrual periods and a decrease in the size of their ovaries. Exposure to this chemical compound has also been associated to birth defects spina bifida and anencephaly (Lupo, et.al., 2010, 2010). For men, exposure to this compound has been known to cause abnormal amount of chromosomes in the sperm, thereby causing issues in fertility and infant development (Lupo, et.al., 2010). The vapor from the products which have benzene like glues, furniture wax, as well as detergents has been considered the major source of exposure. Many of these products with benzene have long been modified in order to reduce or remove their benzene content (US National Library of Medicine, 2002). The air around waste sites and gas stations has also been known to contain a high degree of benzene. Since petroleum products are complex mixtures, risk evaluation often focus on specific toxic elements (US National Library of Medicine, 2002). Such petroleum elements which have long been considered of major interest to health have always included aromatic hydrocarbons, including benzene, ethylbenzene, toluene, and xylenes (US National Library of Medicine, 2002). In the US, the Occupational Safety and Health Administration (OSHA, 2011) indicates that compounds or mixture of compounds are presumed to be cancer risks if they have components of 0.1% or higher of elements known to be carcinogens. The atmosphere itself is already known to contain a small amount of benzene from automobile fuel service stations, tobacco smoke, automobile exhausts, wood smoke, as well as emissions from industrial plants (OSHA, 2011). In actuality, 50% of benzene in the US comes from exposure to tobacco smoke. Benzene inhaled is often expelled with hardly any change. Based on studies involving humans, about 16-4 to 41.6% of benzene which remained in the lungs was eliminated only after five to seven hours following two to three hours exposure to the compound (NIOSH, 2010). The remaining compound was later eliminated in the urine. Benzene absorbed through the skin often underwent metabolism in the liver, and later eliminated in the urine. Exposure limits to the compound has been described by the United States Environmental Protection Agency at maximum level in drinking water at 0.005 mg/L (OSHA, 2011). This is based on the criterion in the prevention of leukemia within the general population. The maximum contaminant level goal is to ensure zero benzene on the drinking water. However, among workers exposed to benzene, these risks cannot always be prevented. 2.2. Monitoring, detection, and diagnosis Airborne exposure monitoring is based on the proper evaluation of personal exposure and efficacy of engineering controls (OSHA, 2001). Initial exposure monitoring must be based on industrial hygienist of individuals who has the proper training and experience sampling techniques. Workplaces with benzene exposure must have benzene monitors, mostly air monitors to determine level of exposure (OSHA, 2001). Representative 8-hour TWA exposures must be based on one sample representing one full shift. The OSHA relies on up-to-date protective limits established by organizations including the American Industrial Hygiene Association. Results of air monitoring are then compared to the lowest Occupational Exposure Limit (OSHA, 2001). Based on the National Center for Environmental Assessment (1998), the toxicity of benzene is based on its biotransformation to reactive species. Benzene is processed by the liver through the cytochrome P450 2E1, breaking it down to its basic elements – phenol, hydroquinone, and catechol (National Center for Environmental Assessment, 1998). The specific toxicity of these metabolites into blood and bone marrow is difficult to sufficiently explain, as a result, the metabolites are seen as the proximate; with possible secondary activation to toxic quinones and free radicals via the peroxidase enzymes of the bone marrow (National Center for Environmental Assessment, 1998). This toxicity is supported by studies on rodents where their target organs for toxicity are rich in peroxidase and sulfatase enzymes. There is also evidence which indicates that various metabolites are seen in benzene toxicity. Molecular targets for the specific interaction of metabolites include tubulin, histone proteins, topoimerase II, and other proteins linked with the DNA (National Center for Environmental Assessment, 1998). Any damage to these proteins can cause DNA strands to break, cause mitotic recombination, and chromosomal translocations. In instances where these damages occur in the stem or the early progenitor cells, a leukemic clone with a specific advantage in growing can result due to protooncogene activation, activation, gene fusion, and suppressor-gene inactivation (National Center for Environmental Assessment, 1998). The epigenetic impact of benzene on the bone marrow stroma and on the stem cells can support the development of a leukemic clone. Within the bone marrow, various cells can impact on various targets, including hematopoietic and lymphopoietic stem cells, committed progenitors, immature hematopoietic precursors, and different cells involved in bone marrow development (National Center for Environmental Assessment, 1998). The US EPA (1985) also firmly declares that benzene is a carcinogen based on all routes of exposure. This is based on evidence from human epidemiologic studies, animal studies, and data seeking the improvement of mechanisms of action, as well as various studies on the skin absorption in humans and animals. The human epidemiological studies have indicated without doubt that benzene can lead to acute nonlymphocytic leukemia as well as other blood disorders, like preleukemia and aplastic anemia (Infante, et.al., 1977). There is also a significant possibility on exposure being very much related to higher possibilities of chronic lymphocytic leukemia or multiple myeloma (DeCoufle, et.al., 1983). As far as experimental animal species are concerned, exposure to the compound has been known to cause cancer on various organs, including the mouth and the nose, the liver, the lungs, ovaries, and the mammary glands. These responses are also attributed to interactions of the metabolites of the compound. Evidence also indicates that there are various pathways causing cancer, and most likely leukomogenesis due to exposure to the compound. 3. Past and existing studies conducted; validity and generalizability of studies The study by Aksoy (1987), three of the 58 patient respondents had leukemia and the first case chronic lymphatic leukemia was seen in a 43-year old male who inhaled a solution of benzene using these for control purposes in a print shop and working there for 2-3 hours per day for 2 years. The second case of chronic lymphatic leukemia involved that of a 51-year old male who had not current exposure to the compound, but had previous exposure to a thinner containing 27.3% benzene for 10 years from 1955 to 1965 at a time when he owned a plastic plant. Hairy cell leukemia was seen in a 50-year old manager of a plastic plant who saw exposure to benzene from 1957 to 1965. Based on these studies, the author concluded that the short-term and intermittent exposure to the compound may account for the varying distribution of the kinds of leukemia apparent alongside benzene toxicity (Aksoy, 1987). The authors applied appropriate research methods using a research design which allowed for a clear evaluation of the research topic. The statistical treatment appropriately collated and computed the study results, based on variables and relationships of variables. The significance of results was deduced from the results of the statistical treatment. Due to the limited sample population covered however, the results of this study could not be generalized to a larger population. In Turkey, Aksoy and colleagues (1987) evaluated the blood samples of about 900,000 workers in about 40 workplaces in Istanbul and Izmit. Exposure to benzene in this population was about 1 month to 40 years and atmospheric levels were at 0.73%. Benzene was seen in various thinners, solvents, dyes, lacquers; but levels decreased since the 1970s. Among the worker respondents, hematological abnormalities were apparent with about five cases of hematopoietic cancers, as well as poorly differentiated lymphoma, Hodgkin’s disease, acute lymphoblastic leukemia, and acute myeloblastic leukemia. All of the cases of cancer, except that of Hodgkin’s lymphoma were seen after about five years or less of exposure to the compound or from mixtures of solvents and thinners. This study applied the proper research methodology, fitting the various elements of the study, especially in terms of variables which relate to the impact and effects of benzene. The randomized methods could not be appropriately applied to this study because they were not relevant to the study design. The statistical treatment nevertheless ensured that the results of the study would be able to measure the variables, as well as the study results based on significant relations between variables. The sample population was significant and allowed for a higher generalizability of results. In the study by Arnetz, et.al., (1991), the authors carried out their study on New York Based employees in two Exxon research and development facilities working any span of time from 1964 to 1986, or having been retired during the same time period. Chemical exposure was rated by industrial hygienists. In relation to the general American population, there were lower rates of lymphosarcoma and reticulosarcoma, however their rates in cancer affecting the lymphopoietic tissues was higher than the US general population (Arnetz, et.al., 1991). Death rates were also higher among scientists and engineers, mostly for cancers involving lymphopoietic tissues (Arnetz, et.al., 1991). This implies that exposure to chemicals including benzene also exposes workers to a higher risk for lymphopoietic cancer and their rates, in relation to the general population is significantly higher. The research methodology was able to provide a clear analysis of the study variables and the essential relationships which needed clarification. The sample population was not specific enough, and this reduced the reliability of the results. Balarajan (1983) carried out his study on about 8200 males with cancers of the lymphoid tissue, comparing them with other cancer patients. His study established that in bus and coach drivers 16% had sarcoma and 63% exhibited other neoplasms as compared to individuals who did not share their occupation (Balarajan, 1983). Drivers of road passenger vehicles manifested with neoplasms of the lymphoid tissue. The study therefore indicated that environmental exposure to toxic compounds, including hydrocarbons like benzene also increased the risk for the driver having lymphoma. Blair, et.al., (1992) covered about 620 white males with non-Hodgkin’s lymphoma residing in Iowa and Minnesota, comparing them with about 1200 individuals without the lymphoma. The study was able to establish that for men with non-Hodgkin’s lymphoma, they had a higher ratio of exposure to chemicals like benzene (Blair, et.al., 1992). In effect, individuals who had non-Hodgkin’s lymphoma had a 50% higher exposure rate to benzene as compared to individuals without the disease. Those employed in industries involved in special industrial machinery, real estate, and dry cleaning manifested higher rates of non-Hodgkin’s lymphoma as well as higher rates of exposure to benzene (Blair, et.al., 1992). The research methods fit the needs of the researchers and the research topic itself. It allowed the different variables to be measured in relation to the research issue. The sample population was sufficient and large enough to measure significant research results. Hence, the results could be generalized to a bigger population. A study by Bond, et.al., (1986) sought to study the deaths of 950 Dow employees involved in chlorobenzol, alkylbenzene, and ethyl cellulose operations, comparing their cases with the US general white male population. Exposure to benzene was evaluated into four levels based on intensity and about 25% of the respondents were involved in jobs having exposure to benzene (Bond, et.al., 1986). There were two cases of reticulosarcoma noted, actually more than expected. Malignancies of lymphatic and hematopoietic origin were seen among the workers. As a result, the authors concluded that there is no strong relation to benzene being the single cause of death, however, co-factors in alkylbenzene plants indicate that it is the direct cause of myelogenous leukemia. The research methodology applied to this research provided an appropriate measure for the research topic and its related variables. The authors were also able to apply ethical research processes, in relation to the inclusion as well as assessment of medical records. The sample population included was large enough for this study, enabling a sufficient measurement of the variables. In associating the relationship between leukemia and the rubber industry, Checkoway and colleagues (1984) carried out their case control evaluation of lymphocytic leukemia among rubber plant workers. Their study also measured benzene levels for each department. Odds ratio for development lymphocytic leukemia after having been exposed to benzene was at 2.5; four cases of lymphocytic leukemia had positive exposure to benzene (Checkoway, et.al., 1984). The authors firmly declared that there was a need to carry out more studies, expanding the scope of the study and covering a wider range of lymphopoietic malignancies. The methods applied were clearly explained and were appropriate for measuring the impact and relationship of the variables with each other. Odds-ratio statistical treatment allowed for appropriate measures of the variables, especially in relation to benzene and its impact. The researchers did not however specifically define the population, making it difficult to establish the generalizability of the results. Decouffle, et.al., (1983) evaluated the deaths of 259 men working for any length of time from 1947 to 1960 in an alkylbenzene manufacturing plant. The study revealed that four men died from hematopoietic neoplasms; this was a higher rate as compared to the regular white male population. Two of the deaths were attributed to multiple myeloma, and another was attributed to chronic lymphocytic leukemia. In yet another study, Fabbro, et.al., (2001) discussed, in the case-control study covering 455 cases of non-Hodgkin’s lymphoma, that at least a one year exposure to benzene increased the odds of developing non-Hodgkin’s lymphoma. Cumulative exposure to benzene amounting to more than 810 days indicated an even higher odds ratio for developing the disease. Exposure to benzene for 15 years of more also indicated high rates for non-Hodgkin’s lymphoma. This study applied an appropriate research method which ensured adequate measurement and interrelation of variables. The researchers also applied statistical tools which established clear answers to the research questions raised. The time lapse also allowed the assessment of the respondents through several years. The significant number of respondents allowed the results to be generalized to a larger population. In a 1996 study by Fu and colleagues, the authors assessed death rates for shoe manufacturers. The first cohort covered three English towns, which included a population of male shoe and boot manufacturers. The second cohort covered 2008 workers employed in a shoe manufacturing plant between 1950 and 1984. Benzene was used in the glues in the shoemaking industry in Florence, Italy, and benzene was said to comprise about 70% of the glue’s weight. Restrictions on the amount of benzene were later reduced to 2% (Fu, et.al., 1996). Exposure to benzene in France is higher than exposure in England. Based on the France cohort, workers with high exposures to benzene had high mortality rates, mostly due to non-Hodgkin’s lymphoma (Fu, et.al., 1996). For workers in Florence, the rates for non-Hodgkin’s lymphoma was high, and the exposure to benzene among these workers was also high. This study applied clear ethical guidelines in terms of establishing observations on benzene exposure to workers. It applied a more simplistic statistical computation, mostly based on percentages. The method chosen was able to establish clear measures of variables, and it allowed the researchers to measure the relationship between non-Hodgkin’s lymphoma and level of benzene exposure. Random methods were not applicable to this study, but a sufficient population was included in the evaluation process. As such, the validity and generalizability of the results was ensured. 4. Prevention and control 4.1 Education Teaching the workers about the chemical is the most important aspect of prevention and control in benzene exposure (Wolf and Noonan, 2009). Educating the employees of the risks to their health, including the importance of taking the necessary precautions to avoid exposure would help engage their cooperation in these prevention measures. 4.2 Engineering In order to prevent and control benzene exposure, it is important to get as much fresh air as possible during and soon after exposure to the toxic chemical. Where exposure to benzene is in the workplace, adequate ventilation must be installed (Wolf and Noonan, 2009). After exposure to the chemical, thorough washing of the body and clothes must be carried out. If possible, clothes must be discarded and not reused. Thorough washing with soap and water must be carried out after each exposure and signs including eyes burning and vision blurring must be followed by rinsing eyes with plain water (Wolf and Noonan, 2009). Proper disposal of clothes must also be carried out, sealing disposal units and avoiding any further exposure to the contaminated clothing. 4.3 Enforcement For employers, workers using benzene must be given the proper protective equipment, including mask, gloves, goggles, full body protective suits, as well as footwear. Air monitoring within the facility must be available and visible within the premises, indicating the toxic levels of exposure, and the current level of the atmosphere inside the premises (Wolf and Noonan, 2009). In case threshold levels are reached, buzzers or sirens must be set-off and emergency evacuation procedures carried out for employees. Where levels are lowered to acceptable standards, work can then be resumed. Benzene exposure must not exceed the following levels: 8 hours for 10 ppm benzene, with a ceiling of 25 ppm; for cases of 50 ppm, maximum length of exposure must only be for 10 minutes (NIOSH, 2003). For work clothing which becomes wet, these should immediately be discarded due to flammability risks. Employers must provide bathing and wash areas for their workers, with areas where they can also immediately discard of their protective equipment for easy disposal. 5. Future direction 5.1 Research needs Based on the above studies, it is apparent to note that more studies on the impact of benzene exposure to cancer risks among workers exposed to benzene must be carried out. These studies must also consider the level of exposure, including the duration of exposure and amount of exposure on the cancer risk itself (CDC, 2006). A larger population must be covered, especially on shoemakers and other workers often exposed to benzene. Cancer risk must also be evaluated especially in terms of the application of protective measures and safety equipment. 5.2 Socio-political The appropriate regulatory measures must be lobbied with the congress, mostly asking for laws passed banning the use of this toxic chemical or the strict regulation of benzene exposure (CDC, 2006). Imposing harsh punishment for violators must also be considered. Companies actively using benzene, especially those which do not provide protective equipment to their workers must be boycotted. 5.3 Law enforcement Monitoring by the OSHA must be regular, at least once every month, with regular surprise visits in order to check the compliance of the company with benzene exposure regulations (Wolf and Noonan, 2009). Companies and employers violating these regulations must be immediately charged with the proper legal remedies. Fines must be increased, and repeat violators, must be shut down. 5.4 Health education Health education must be regularly carried out with employees, as well as employers. The health education must include a thorough information drive on benzene, its impact, its risks, and the control measures which can be imposed in order to reduce its impact (Wolf and Noonan, 2009). 7. Public health implication The above discussion indicates the importance of strictly implementing health regulations in relation to benzene. The pressure is on government enforcement agencies to implement strict monitoring activities on companies using benzene (CDC, 2006). The public must also be informed that benzene is a carcinogenic and that workers agreeing to be exposed to the chemical must be fully aware of the health risks they are exposing themselves to. The public in the immediate vicinity of the company or plant using benzene must also be made aware of the risks that they may be exposed to simply by being in the vicinity of the plant (Wolf and Noonan, 2009). Very much like toxic chemicals like asbestos, there must be a certain acceptable distance where other buildings of people can be allowed to inhabit. 8. Summary The above discussion indicates the impact of benzene on general human health and on workers. Benzene is a toxic chemical compound which in its entirety is considered to be a hydrocarbon. It is an additive for various industries, including shoemaking (glue), petroleum industry, as well as other industrial plants. As an additive, it can take on liquid, solid, and gaseous forms, thereby causing various instances of exposure for man. The health risk for this compound is mostly related to the blood marrow functions, and as a result, it is known to cause leukemia and other blood disorders. Studies indicate how many workers, shoemakers, petroleum workers, etc have a high risk for developing leukemia and these studies also indicate that there is indeed a link between leukemia and benzene. At present, the levels of benzene in most products have been reduced, however, a certain percentage of the compound is still present in various chemicals. This is still therefore a major concern because the EPA acknowledges that the only safe level of benzene is zero. It is therefore important for managers to establish occupational safety conditions for their workers to reduce direct exposure or to reduce the benzene components of their raw materials to acceptable and safe levels. References Aksoy, M. (1985). Malignancies due to occupational exposure to benzene. American Journal of Industrial Medicine, vol. 7: pp. 395-402. Aksoy, M. (1987). Chronic lymphoid leukemia and hairy cell leukemia due to chronic exposure to benzene: report of three cases. 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