Multicenter Study of Environmental Contamination with Antineoplastic Drugs in 36 Canadian Hospitals: A 2013 Follow-up Study

Abstract

No occupational exposure limit exists for antineoplastic drugs. The main objective of this study was to describe environmental contamination with cyclophosphamide, ifosfamide, and methotrexate in pharmacy and patient care areas of Canadian hospitals in 2013. The secondary objective was to compare the 2013 environmental monitoring results with previous studies.

Six standardized sites in the pharmacy and six sites on patient care areas were sampled in each participating center. Samples were analyzed for the presence of cyclophosphamide, ifosfamide, and methotrexate by UPLC-MSMS. The limit of detection (LOD) in pg/cm² was 1.8 for cyclophosphamide, 2.2 for ifosfamide, and 7.5 for methotrexate. The 75th percentile of cyclophosphamide concentration was compared between the 2013, 2008–2010, and 2012 studies.

Thirty-six hospitals participated in the study and 422 samples were collected. Overall, 47% (198/422) of the samples were positive for cyclophosphamide, 18% (75/422) were positive for ifosfamide, and 3% (11/422) were positive for methotrexate. In 2013, the 75th percentile value of cyclophosphamide surface concentration was reduced to 8.4pg/cm² (n = 36), compared with 9.4pg/cm² in 2012 (n = 33) and 40pg/cm² (n = 25) in 2008–2010. The 75th percentile for ifosfamide and methotrexate concentration remained lower than the LOD.

The 2013 study shows an improvement in the surface contamination level, and a plateau effect in the proportion of positive samples.

Keywords:

• cyclophosphamide
• environmental monitoring
• hospital
• ifosfamide
• methotrexate
• occupational exposure
• pharmacy service