Prevention Guide - Safe Handling of Hazardous Drugs - Irsst

2. RISKS RELATED TO THE USE OF HAZARDOUS DRUGS
2.3 Data Regarding Exposure and Its Effects
2.3.1 Contamination of the Work Environment
Many studies have confirmed the presence of contamination in areas where hazardous drugs are handled,
including the pharmacy, oncology units and the rooms of patients who have received chemotherapy.
Since 1990, at least 14 studies have measured surface contamination by one or more drugs (those most often
measured are cyclophosphamide, ifosfamide, fluorouracil, and methotrexate). All of the studies showed
measurable amounts of drugs in the work environment.
A study conducted in 1999 (Connor, 1999) in six Canadian and American hospitals revealed the presence of
contamination, by at least one of the three drugs measured, in 75% of pharmacies and 65% of drug administration
areas. In the preparation areas, the contamination was often higher outside the hood than inside. The authors noted
that the hood does not offer complete protection and that the preparation techniques are very important. The level
of contamination was lower in the administration areas; the most contaminated areas were the floor around the
patient’s chair or bed, the arms of the patient’s chair and the work table or counter.
The preparation and administration areas are not the only trouble spots. A study conducted in Holland in 2005 also
showed contamination in the rooms of patients who had received chemotherapy (Fransman, 2005). For example,
all of the urinals and bedpans, all of the cloths used to wash the patients and 60 to 82% of the cloths and mops
used to clean the room were contaminated with hazardous drug residue. This contamination resulted, in turn, in
contamination of gloves or hands and, occasionally, the forearms and foreheads of the nurses or cleaners. In a
number of cases, the workers were not wearing gloves. Wearing gloves reduced hand contamination by 1.6 to 4
times, depending on the task concerned. Bussières et al. published a summary of the contamination data in an
Institut national de santé publique du Québec newsletter (Bussières, 2006b).
In summary, contamination of the work environment has been well-documented by many authors. Assessments
performed in a number of Quebec institutions as part of a pilot study carried out with the INSPQ indicates that a
similar situation exists in Quebec.
2.3.2 Health Effects of Exposure
According to the Alert issued by NIOSH in 2004, “Working with or near hazardous drugs...may cause skin rashes,
infertility, miscarriage, birth defects and possibly leukemia and other cancers”.
Despite improvement in the safety of pharmacy department practices, recent studies have shown that the workers
may still be exposed. During the past decade, a number of investigators have demonstrated that concentrations of
various hazardous drugs could be found in the urine of those administering or preparing the drugs (Sessink 1992,
Ensslin 1994, Nygren 1997, Turci 2003, Fransman 2006, NIOSH 2004, Bussières 2006). This finding is of even
greater concern as these drugs can have toxic effects (as noted in the NIOSH document). The carcinogenic effect
of some drugs in animals is recognized and research tends to demonstrate that these drugs may promote the
development of new cancers in the individuals treated. Table 2 lists certain drugs known to be carcinogenic or
probably carcinogenic in humans (Connor, 2006).
The consequences of occupational exposure are, however, difficult to document and the study results lack
consistency because the facilities and work methods are constantly changing. Genotoxic effects have been
demonstrated and adverse reproductive effects, such as fetal death, congenital malformations, infertility and an
increased risk of leukemia, are a real concern (NIOSH 2004, Dranitsaris 2005, Fransman 2007, Bussières 2006).
The only statistically significant finding of a recent systematic review and meta-analysis of the health effects of
hazardous drugs was an increased risk of spontaneous abortion in exposed workers (OR 1.46; CI 1.11 - 1.92 [see
“Risk Measurement” box]) (Dranitsaris, 2005). While not statistically significant, the other effects are not ignored,
in particular, an excess risk of congenital malformations (OR 1.64; CI 0.91 – 2.94) and stillbirth (OR 1.15; CI 0.75
– 1.82). Because of their number and size, however, these studies do not allow a significant degree of accuracy.
2-10 ASSTSAS PREVENTION GUIDE – SAFE HANDLING OF HAZARDOUS DRUGS