Antineoplastic drug exposure raises concern

NIOSH study to test workers, environment

Health care workers may continue to be exposed to dangerous antineoplastic drugs, even if they follow recommended precautions for handling the drugs.1 That finding from recent studies has prompted the National Institute for Occupational Safety and Health to launch a study of antineoplastic drug exposure and its health effects.

The study will be the first in the United States to both measure environmental exposure and conduct health assessments of employees. It will involve at least three hospitals and about 100 nurses, nursing assistants, pharmacists, and pharmacy technicians. NIOSH is collaborating with the University of Maryland in Baltimore, the University of North Carolina in Chapel Hill, and the M.D. Anderson Cancer Center in Houston.

"We are going to be looking at endpoints, including trying to actually measure specific marker drugs in employees [in their urine and/ or blood]," says Melissa McDiarmid, MD, MPH, director of the occupational health program and professor in the School of Medicine at the University of Maryland. "We’re going to do a very solid environmental exposure assessment, measuring all kinds of environmental sampling at the same time we are studying the workers. That’s going to give us a snapshot of where we are now."

Later this year, NIOSH is expected to release a hazard alert on antineoplastic drugs, urging hospitals to use caution and follow OSHA guidelines for handling the drugs.2 Ultimately, this study and others like it could lead to changes in recommended practices.

Antineoplastics more widely used

"Hopefully we will be able to make recommendations to each [study] facility about where they might be able to minimize exposure," says D. Gayle DeBord, PhD, chief of the biomonitoring and health assessment branch in the division of applied research and technology at the National Institute for Occupational Safety and Health in Cincinnati.

The study is particularly important because the use of antineoplastic agents has become much more widespread, notes DeBord.

"We have more cancer patients now than we’ve had in the past, and the use of chemotherapy is going up," she says. "A lot of these antineoplastic drugs are being used for non-cancer treatment, as well, such as for rheumatoid arthritis. Not only do we have oncology nurses who are at risk, [but the drugs] are also being administered in some areas by other nurses who may not be as well-trained."

On oncology units, nurses joke wryly about getting their "maintenance dose" of the dangerous drugs. "There’s this awareness, this level of knowledge about it. And they’ve turned it into a sort of dark humor," says McDiarmid.

Oncology nurses may, in fact, be getting a low-level daily exposure. Thomas Connor, PhD, senior service fellow at NIOSH in Cincinnati and former associate professor of environmental and occupational health at the University of Texas School of Public Health in Houston, measured surface contamination in six U.S. and Canadian cancer centers.

"We found drugs everywhere we looked in the pharmacy and the treatment areas," he says. "There are a number of studies in the literature that have confirmed this in the United States and Europe. [The hospitals] were using all the recommended procedures and equipment and personal protective equipment."

Connor even found contamination in the hallways, possibly endangering people who were not even aware of the presence of toxic chemicals. Connor’s conclusion: "People outside the actual preparation and administration areas have the potential to be exposed."

Housekeeping staff also may be at risk, says DeBord. Antineoplastic drugs can be eliminated through urine, and urine-soaked linens and contaminated surfaces in a patient’s room could lead to inadvertent exposure, she says.

Health care workers also need to know that standard gloves do not provide sufficient protection against antineoplastic agents, says Connor. ASTM International, a standard-setting body in West Conshohocken, PA, is finalizing new standards for chemotherapeutic gloves.

Drugs linked to reproductive events

DeBord and Connor will be looking for markers for antineoplastic drugs in the urine of pharmacists and nurses in the upcoming NIOSH study. Some participants will provide a daily urine sample for 45 days, and women will provide information on their menstrual cycles. All participants also will provide blood samples and will answer questionnaires about their medical history, work history, and work practices.

Exposure to antineoplastic drugs has been linked to reproductive problems, including miscarriage and spontaneous abortion, and they are known carcinogens.

It may be that workers are only being exposed to very low concentrations of these drugs, but the exposures are repetitive, notes McDiarmid.

"In what other work environment do we allow just a little bit [of a hazardous substance] to be around?" she says. "Some of these have a toxic profile similar to benzene, yet we don’t allow a little bit of exposure to benzene."

References

1. Connor TH, Anderson RW, Sessink PJM, et al. Surface contamination with antineoplastic agents in six cancer treatment centers in the United Sates and Canada. Am J Health-Syst Pharm 1999; 56:1427-32.

2. U.S. Department of Labor. Controlling occupational exposure to hazardous drugs. OSHA Technical Manual 1999; OSHA Instruction TED 1-0.15.