Carcinogens occupational exposure

Benzene is considered to be carcinogenic to humans by the inhalation route of exposure (EPA weight-of-evidence Group A, human carcinogen). Occupational exposure to benzene was associated with increased incidences of nonlymphocytic leukemia. Studies in animals also found increased incidences of neoplasia in animals treated by inhalation or gavage with benzene. 

Potential occupational carcinogen occupational exposure should be limited to the lowest feasible concentration. 

NIOSH carcinogen occupational exposures to carcinogens should be limited to the lowest feasible concentration. (see discussion above about proposed NIOSH policy change )... 

The different toxicity and bioavailability of Cr(III) and Cr(VI) are a public health concern and therefore require strict control. Cr(VI) is considered to be toxic and carcinogenic, especially for the respiratory tract. In occupational health, the OEL (Occupational Exposure Limits) for water soluble and certain water insoluble compounds in indoor air is set at 0.5 mg/m for Cr, 0.5 mg/m for Cr(III), and 0.05 mg/m for Cr(VI), reflecting the different toxicities of both species. 

H. Safety considerations. The Occupational Safety and Health Administration (OSHA), US Department of Labor, standard entitled Occupational Exposure to Hazardous Chemicals in Laboratories (29 CFR 1910.1450) makes it necessary to address safety issues in the SOP. The standard requires laboratories that use hazardous chemicals to maintain employee exposures at or below the permissible exposure limits specified for these chemicals in 29 CFR Part 1910, Subpart Z. Hazards associated with any specific chemicals used in a method must be addressed so that the user has the information needed to follow the Chemical Hygiene Plan for their laboratory. The method developer should limit the use of hazardous chemicals where feasible. The use of toxic and/or carcinogenic reagents should be avoided or eliminated as much as possible. Additionally, the cost of disposal is increasing and could impact the practicality of a method. Material Safety Data Sheets for the analyte(s) and any unusual or hazardous reagents should be provided for the user. 

Mineral Oil Hydraulic Fluids. There is limited information on the toxicity of mineral oil hydraulic fluids in humans. A single case report of a child accidentally ingesting a single dose of automotive transmission fluid provides limited information on death and systemic effects. A case-control study provides some information on the carcinogenicity of mineral oil hydraulic fluids. The study population was exposed via inhalation and dermal routes. An occupational exposure study provides information on neurotoxicity following chronic dermal exposure. Information on the toxicity of mineral oil hydraulic fluids is limited to a series of inhalation, oral, and dermal acute-duration exposures. These studies provide information on death, systemic effects, and neurotoxicity by inhalation, oral, and dermal routes, and immunotoxicity following dermal exposure. 

The information available regarding the association of occupational exposure to lead with increased cancer risk is generally limited in its usefulness because the actual compound(s) of lead, the route(s) of exposure, and level(s) of lead to which the workers were exposed were often not reported. Furthermore, potential for exposure to other chemicals including arsenic, cadmium, and antimony occurred, particularly in lead smelters, and smoking was a possible confounder (Cooper 1976 IARC 1987). These studies, therefore, are not sufficient to determine the carcinogenicity of lead in humans, and the following discussion is restricted to the most comprehensive of these studies. 

The U.S. Public Health Service (USPHS 1993) recommends that occupational exposure to hexavalent chromium compounds should not exceed 1 pg/m3 air for a 10-h workday and 40-h workweek because all hexavalent chromium compounds are potential carcinogens. Other recommendations include more research on ... 

IARC, Jet Fuel, Occupational exposures in petroleum refining, crude oil, and major petroleum fuels, IARC Monogr. Eval. Carcinogen. Risks Hum., 45, 203, 1989. 

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. 

Data adequacy The key study was well designed, conducted, and documented used 20 human subjects and utilized a range of concentrations and exposure durations. Occupational exposures support the 8-h AEGL value. The mechanism of headache induction (vasodilation) is well understood and occurs following therapeutic administration of nitrate esters to humans. Animal studies utilized several mammalian species and addressed metabolism, neurotoxicity, developmental and reproductive toxicity, and potential carcinogenicity. ... 

Limited epidemiological studies have been conducted involving occupational exposure in workers, primarily by the respiratory route (Ratcliffe et al. 1987 Takahashi et al. 1981 Ter Haar 1980 Wong et al. 1979). These studies neither confirm nor refute the possibility of 1,2-dibromoethane as a human carcinogen. Carcinogenicity bioassays have been conducted in animals via the inhalation. 

Table 6.1 Some of the 95 chemicals and occupational exposures currently listed by I ARC as carcinogenic to humans...

Universal precautions training that complies with the OSHA standard on occupational exposure to bloodborne pathogens, as well as a fire training program, should be provided on an annual basis for all laboratory employees. Personnel are required to use proper personal protective devices when handling corrosive, flammable, biohazard, or carcinogenic substances. Eye wash sta-... 

Hayes RB (1997) The carcinogenicity of metals in humans. Cancer Cause Control 8 371-385 HCN (2005) Health Council of the Netherlands Committee on Updating of Occupational Exposure Limits. Octane health-based reassessment of administrative occupational exposure hmits. Health Council of the Netherlands, the Hague. Available at 2000/150SH/156. http // www.gr.nl/pdf.php ID=1315 p=l... 

It is postulated from epidemiologic studies that fibrous materials are also carcinogenic or cocarcinogenic. Lung cancer and mesothelioma (cancer of the pleura) have both been linked to occupational exposure of fibrous materials. The mechanisms of induction of these, as most cancers, are thought to start as changes in the affected cells. 

No data have been located relating to carcinogenicity in humans exposed to 1,4-dichlorobenzene via inhalation, orally, or dermally. Epidemiological studies which used occupational exposure data would be useful to elicit such information on human exposure and potential cancer risks to 1,4-dichlorobenzene. 

There are limited epidemiological data regarding carcinogenicity in humans following chronic inhalation exposure to kerosene. In one case-control study, there was no association between the use of kerosene stoves for cooking and bronchial cancer in nonsmoking women (Chan et al. 1979). In another case-control study, there was no association between renal cell cancer and occupational exposure to fuel oils. 

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