Melissa A. McDiarmid, MD, MPH
In her role as division head of Occupational & Environmental Medicine at the University of Maryland, Melissa A. McDiarmid, MD, MPH, spends a lot of her time working with individuals who have been occupationally or environmentally exposed to toxic substances, among them veterans and healthcare practitioners. Named an honorary member of the Oncology Nursing Society last year, she is a noted researcher in the area of safe handling of chemotherapy and other hazardous drugs and serves as a member of the committee guiding the new USP 800 chapter, Hazardous Drug-Handling in Healthcare Settings, which is in its final stages of development. In a recent interview with Oncology Nursing News
, McDiarmid shared insights gleaned from her more than 30 years in the field.
Oncology Nursing News: How aware would you say oncology nurses are of the risks posed by exposure to hazardous drugs?
: This has been a long journey, and in the beginning, it was a lonely one. Thirty years into it, there is more awareness among a greater number of people. We’re certainly making progress, but I do think we can do better. I’d like to think that we’re at a tipping point where a large enough population of affected professionals has come to realize that this really isn’t some kind of aberration or overkill: safety really does have to be part of the everyday practice of oncology care.
Are pharmacists more aware of the risks than nurses?
I think it’s a function of the individual. The pharmacy community was the first to hear the message, because investigators in their own community started looking at the early evidence, based on Ames mutagenicity testing in the urine of pharmacy workers who were preparing drugs. The pharmacy community also demonstrated that the old way of preparation—using a horizontal pharmacy hood which blew air right into the face of the pharmacy preparer—increased urine mutagenicity. When they moved to a vertical laminar flow hood, the predecessor to the more common designs used now, the urine mutagenicity went away.
For oncology nurses, what are the most important considerations to reduce risk?
For oncology nursing professionals, certification requirements needed for the handling of hazardous drugs have fostered better awareness, and a larger number in the community have a basic understanding of the need for safety than was true 25 or 30 years ago.
But if I had to focus on one practice priority, it would be to say that we’re all human, and I think where mistakes tend to be made is when we rush—when we’re asked to handle an additional patient or cover for someone who has dropped out of the schedule.
You were part of a literature review of studies by the National Institute of Occupational Safety and Health (NIOSH) and others related to the reproductive risks of exposure to antineoplastic drugs in the healthcare setting.1 What did you and your coauthors find?
In a nutshell, I think a lot of people know that a number of these anticancer agents cause second malignancies, but the vast majority of them are also reproductive and developmental toxic substances—the term we use is reproductive toxicants. The older line agents, like cyclophosphamide, the ones that have been around for years—a number of these cause cancer but they also cause reproductive abnormalities which means they can affect the ability of an adult male or female to conceive. A number are also developmental toxicants; this means these toxicants can affect the developing fetus, and you can see typically the risk of spontaneous abortion increases in addition to other abnormalities like congenital malformations. This was all around us during our practice. We weren’t as aware as we needed to be about it. Now, that’s the principal driver of concern for a lot of people in addition to the potential risk of exposure to these agents which are also human carcinogens.
What are the risks of “low-level” chronic exposure versus an acute event like a spill?
Our principal concern is ongoing, low-level “dose” exposure. We all probably in our practice lifetime have experienced spills, but what we need to be focusing on is the everyday exposure opportunity—a term I use to convey how a clinician is at risk for exposure every time. My principal concern—and it is one shared by others who are studying this—is this long-term expo- sure to low concentrations of drug frequently without our knowledge. You don’t necessarily see liquid droplets, particulate, or very fine mists that we are not aware we are being exposed to.
What will be the impact of the USP 800 standards that are aimed specifically at risk reduction for healthcare practitioners handling hazardous drugs, once they are finalized?
I would hope that the people affected by these rules understand that these are not “one-hit wonders” that are coming from various agencies like USP, NIOSH, and OSHA, but rather, there has been a coming together of the regulatory agencies—based on the science—to develop a harmonized approach to safety, and this involves a combination of controls to protect the worker.
How can institutional “buy-in” on these safety measures be achieved?
My “sermon” when I speak to hospital leader- ship includes first: there is not another industry in the United States that allows its employees to handle human carcinogens where safety provisions are only optional; it does not exist except in healthcare. Second: this is also a patient safety issue. Controlling hazardous drug spread throughout a facility protects patients as well. This includes the widespread exposure to what we call “fugitive aerosol.” That’s a threat to everyone who comes into the organization, including patients, families, bystanders, and contractors. It makes sense to me that we would want a comprehensive system of safety to control exposure to these highly toxic agents. Finally, if the safety interventions we were recommending did not cost any money, no one would be talking about the adequacy of the science. The quality of the science has gotten quite good in the 30 years I have been thinking about this problem. We’ve demonstrated the risks, and we’re at the point where we need to stop arguing about the evidence and focus on the solution.
1. Connor TH, Lawson CC, Polovich M, McDiarmid M. Reproductive health risks associated with occupational exposures to antineoplastic drugs in healthcare settings: a review of the evidence. J Occup Environ Med