Multicenter study of environmental contamination with cyclophosphamide, ifosfamide, and methotrexate in 48 Canadian hospitals

Abstract

Context Oncology workers are occupationally exposed to antineoplastic drugs. This exposure can induce adverse health effects. In order to reduce their exposure, contamination on surfaces should be kept as low as possible. Objectives To monitor environmental contamination with cyclophosphamide, ifosfamide, and methotrexate in oncology pharmacy and patient care areas in Canadian hospitals. To describe the impact of some factors that may limit contamination. Methods This is a descriptive study. Twelve standardized sites were sampled in each participating center (six in the pharmacy and six in patient care areas). Samples were analyzed for the presence of cyclophosphamide, ifosfamide, and methotrexate by ultra-performance liquid chromatography tandem mass spectrometry technology. Descriptive statistical analyses were done and results were compared with a Kolmogorov–Smirnov test for independent samples. Results In 2015, 48 hospitals participated in this study (48/202, 24%). Overall, 34% (181/525) of the samples were positive for cyclophosphamide, 8% (41/525) for ifosfamide, and 6% (31/525) for methotrexate. The 75th percentile value of cyclophosphamide surface concentration was 6.9 pg/cm2. For ifosfamide and methotrexate, they were lower than the limit of detection. Centers who prepared more antineoplastic drugs per year and centers who used more cyclophosphamide per year showed significantly higher surface contamination ( p < 0.0001). Over the years, we observed a reduction in surface contamination. Conclusion In comparison with other multicenter studies that were conducted in Canada, the concentration of antineoplastic drugs measured on surfaces is decreasing. Regular environmental monitoring is a good practice in order to maintain contamination as low as reasonably achievable.