Exposure of health care workers to anticancer drugs became problematic in the 1970s. Shortly thereafter, studies began documenting exposure of healthcare workers to these drugs. Investigations employing biological markers, such as urine mutagenicity, chromosomal aberrations, sister chromatid exchanges, and micronuclei, demonstrated associations between occupational exposures and elevated marker levels. Other analytical methods emerged to monitor workplaces where drugs were handled. These contemporary studies uncovered widespread contamination of drugs on work surfaces, trace amounts in air samples, and their presence in the urine of workers. Vials containing these drugs are often contaminated with the drug when they are shipped. Most workplace surfaces are contaminated with the drugs being prepared and used in that area. Other anticancer/hazardous drugs would most likely be used in these areas. The interior surfaces of biological safety cabinets and isolators, floors, countertops, carts, storage bins, waste containers, treatment areas, tabletops, chairs, linen, and other items are all potential sources of exposure to anticancer drugs. Patient body fluids contain the drugs and/or metabolites, often more biologically active than the parent compounds. An exposure assessment of areas where anticancer/hazardous drugs are handled must consider every potential source and route of exposure. Data from surface contamination and inhalation studies suggest that dermal exposure is the primary route of exposure. Assessment of exposure is the first step in providing a safe work environment for these workers. However, because of the many drugs to which they are exposed, any assessment can only be an estimation of the overall exposure.
Thomas H. Connor, Ph.D., NIOSH MS C-23, 4676 Columbia Parkway, Cincinnati, OH 45226