Cancer, occupational causes

It has been estimated that cancer deaths due to asbestos will peak at several thousand per year in the UK alone, and at over 10,000 per year in the USA over the thirty-year period from 1983. The deaths from mesothelioma alone in the UK are believed to number 1,800 and will not reach a peak for another ten years. It is the most common occupational cause of death in the UK Hence, while deaths from most other cancers are decreasing, deaths from asbestos-related cancer are increasing. 

Clapp RW, Howe GK, Jacobs M. Environmental and occupational causes of cancers revisited. J Pub Health Pollcy2006, 27 61-76. 

Georgellis A, Kolmodin-Hedman B, Kouretas D. Can traditional epidemiol ogy detect cancer risks caused by occupational exposure to pesticides J Exp Clin Cancer Res 1999 18(2) 159—66. 

The present status of knowledge in this field is far from relevant, hence one can neither incriminate nor refute the occupational causative factors for childhood cancer and leukemias. The positive associations of occupations and exposures having a higher risk could be used only in setting priorities for further research. 

The approach of Doll and Peto (1981) to estimating the extent of mortality from cancer that is due to occupational causes has been the basis for several subsequent estimations, In one of the most recent of these, a study undertaken to inform the European Commission in its deliberations on current regulatory strategic on controlling hazardous chemicals, Postle et al (2003) estimate that 3.5 per cent of the total cancer mortality in the EU was associated witii occupational exposure to chemicals and the authors suggest that about 20 per cent of such morfedity may stem fiom exposure to currently unknown chemical carcinogens. 

Accounting for approximately two-thirds of all cancers, voluntary cancers caused by smoking and bad diet occupy an exceptional position, these being followed by the endogenously caused cancers. Alcohol, causing 3% of all fatal cancer cases, is as relevant as asbestos. Occupational tumors are predominantly caused by asbestos. These tumors are responsible for approx. 4% of the total number of fatal cancer cases. However, it should be realized that only a small fraction of the population is exposed at the workplace to carcinogens, whereas about 50% of the population smoke and everybody has a genetic risk. 

The tumors of the lung and the costal pleura (mesothelioma) caused by asbestos fibers are the most frequent causes of occupational cancer diseases. About 85% of all fatal occupational cancers are caused by asbestos. Pulmonary tumors are not caused by asbestos only other causes such as smoking are usually of much more importance. 

The purpose of the Centers for Disease Control and Prevention (CDC) is to promote health and quality of life by preventing and controlling disease, injury, and disability. The CDC provides limited information on occupational safety and health. For example, their web page has information about accident causes and prevention, back belts, cancer—occupational exposure, effects of workplace hazards on male reproductive health, latex allergies, needle stick, occupational injiuies, teen workers, and violence in the workplace (see website http //www.cdc.gov). The Center for Health Statistics is located within CDC and provides basic health statistics on the U.S. population. This information is used to identify potential occupational health risks by occupational health researchers (see website http / / WWW.cdc.gov/nchs). 

The effects of chromium compounds have been studied since World War II. While chromic acid mist was known to produce septal perforations in the nose, chrome holes of the skin, and chronic dermatitis, occupationally caused lung malignancies from certain chromate compounds were a newly discovered epidemiological finding. Exposure to vinyl chloride produced angiosarcoma (cancer of the liver) in workers exposed to the chemical. This wasn t discovered until an epidemiological survey revealed workers in plants that had vinyl chloride in the process had abnormally high incidences of liver cancer. 

The majority of cancers are caused by lifestyle and genetic background, a lesser percentage is attributable to sun and radiation exposure, and cancer from occupational (workplace) exposures to chemicals accounts for about 5% of all cancers. 

Occupationally caused skin disease provides a final example of a health problem which fails to generate compensation pressures commensurate with the scale of the problem. A recent study of the records of the Sydney Skin and Cancer Foundation found that only about one in three patients with occupationally caused skin disease had applied for workers compensation and only one in four had actually received compensation, despite the fact that the average time lost from work was one month (Rosen and Freeman 1992.)... 

The study reported that to our knowledge, no prior study uses national data to generate estimates of the burden and costs of occupational injuries and illnesses in the U.S. The report studied fourteen primary sources and 200 secondary sources of data, and went on to identify larger numbers than previously reported in national studies. Between 66,000 and 111,000 new cases of cancer are caused by occupational factors each year, while an estimated 36,000 to 73,000 new or recurrent cases of coronary heart disease are associated with workplace factors. 

The hazards of chemicals are commonly detected in the workplace first, because exposure levels there are higher than in the general environment. In addition, the exposed population is well known, which allows early detection of the association between deleterious health effects and the exposure. The toxic effects of some chemicals, such as mercury compounds and soot, have been known already for centuries. Already at the end of the eighteenth century, small boys who were employed to climb up the inside of chimneys to clean them suffered from a cancer of the scrotum due to exposure to soot. This was the first occupational cancer ever identified. In the viscose industry, exposure to carbon disulfide was already known to cause psychoses among exposed workers during the nineteenth century. As late as the 1970s, vinyl chloride was found to induce angiosarcoma of the liver, a tumor that was practically unknown in ocher instances. ... 

At typical indoor concentrations, COj is not thought to be a direct cause of adverse health effects however, COj is an easily-measured surrogate for other occupant-generated pollutants. Eye, nose, and throat irritation headaches lung cancer may contribute to heart disease buildup of fluid in the middle ear increased severity and frequency of asthma episodes decreased lung function. ETS is also a source of odor and irritation complaints. 

The federal government is concerned about the amount of hexachloroethane that you are exposed to in the environment. The government has established standards and guidelines to prevent you from being overexposed. The Occupational Safety and Health Administration (OSHA) has set a limit of 1 part per million (ppm) for the hexachloroethane in workplace air over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) considers hexachloroethane as a potential occupational carcinogen (can cause cancer) and recommends 1 ppm in air as a tolerance value. 

In the debate about the toxic effects of dyes and chemicals, there is no doubt that carcinogenic effects are perceived by the general public as the most threatening. Chemicals remain a focus for this concern in spite of the weight of evidence that they make only a minor contribution to the incidence of cancer [60,67,83]. The generally accepted estimate of cancer causation, based on mortality statistics, indicates that only 4% of all cancer deaths are attributable to occupational exposure. Another 2% are considered to arise from environmental causes and 1% from other forms of exposure to industrial products. 

Chronic-Duration Exposure and Cancer. Some reports of occupationally exposed workers indicated that low concentrations of hydrogen cyanide may have caused neurological, respiratory, and cardiovascular effects (Blanc et al. 1985 Chandra et al. 1980, 1988 El Ghawabi et al. 1975 Kumar et al. 1992). The route of exposure was predominantly inhalation, although dermal exposure can also occur in the work place. The studies, however, lacked either information about exposure levels or used small cohorts of workers. Studies in populations that used cassava roots as a main source of their diet described the neurological effects of cyanide consumption (Osuntokun 1972, 1980). However, these effects may be due to a recently identified substance, scopeletin, rather than due to cyanide (Obidoa and Obasi 1991). 

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