Various antineoplastic drugs (ADs) are used in large quantities not only as anti-cancer chemotherapies but also as immune suppressants or anti-rheumatic agents etc. (Kümmerer et al., 2016). The still increasing usage patterns of ADs raised concerns for healthcare workers in the pharmacies and hospitals (Connor and McDiarmid, 2006; Dranitsaris et al., 2005; NIOSH, n.d.), and the occupational exposures have been associated with adverse health outcomes in exposed personnel including reproduction toxicity or cancer (IARC; European Commission, 2019) (Cherrie et al., 2017; NIOSH, n.d.). ADs are also discussed as compounds of environmental relevance (Kümmerer et al., 2016), and widespread contamination indoor and outdoor has been extensively studied (Blahova et al., 2020; Fleury-Souverain et al., 2015; Kiffmeyer et al., 2013; Kopp et al., 2013; Odraska et al., 2014; Roland et al., 2017; Sottani et al., 2017).
ADs are chemically diverse compounds that act through various mechanisms and differ in the overall consumption and use. The Supplementary Table S1 summarizes the information on the preparations of ADs in the Czech Republic. A survey of 18 out of 47 pharmacies that have official permission to handle ADs showed that few ADs – cyclophosphamide (CP), platinum-based drugs (Pt), 5-fluorouracil (FU), paclitaxel (PX), gemcitabine (GEM), irinotecan (IRI), ifosfamide (IF) and methotrexate (MET) – are prepared in the large quantities and together comprise 25–80% of all AD preparations with the overall average of 51%. In agreement with previous studies, this shows the high importance of few ADs, namely CP, FU and Pt-based compounds as the representative biomarkers of exposures to ADs (Jeronimo et al., 2015; Kopp et al., 2013; Turci et al., 2003).
The exposures to ADs are most commonly assessed indirectly by analyzing the contamination of surfaces such as floors, desktops, handles, etc. (Astrakianakis et al., 2020), and naturally, the majority of the information is available for pharmacies and medical facilities (Blahova et al., 2020; Fleury-Souverain et al., 2015; Kiffmeyer et al., 2013; Kopp et al., 2013; Odraska et al., 2014; Roland et al., 2017; Sottani et al., 2017). As documented in the literature, surface contamination is highly variable within and between different oncology departments or pharmacies (Chauchat et al., 2019; Odraska et al., 2014). The contamination range from non-detected contamination (low pg/cm2) up to 100 ng/cm2 (documented for CP and FU) or up to 10 ng/cm2 (Pt-based drugs – cis-, carbo- or oxali-Pt) (Astrakianakis et al., 2020; Kopp et al., 2013; Schierl et al., 2009; Turci et al., 2003). Generally, the most frequently and highly contaminated surfaces in the patient care units are the intravenous poles and the floor beneath the infusion stand, surfaces in the toilets and bathrooms, and the areas where chemotherapy infusions or body fluids of patients are handled (Astrakianakis et al., 2020; Kopp et al., 2013; Schierl et al., 2009; Turci et al., 2003).
Concerning the genotoxic action of many ADs, no official exposure limits are available. It is recommended to keep the exposures as low as reasonably achievable. Some studies, however, recommended the use of the individual threshold guidance values (TGV) based on large scales monitoring studies, where TGVs are the statistical values such as the 75th or 90th percentile of the collected data set (Kiffmeyer et al., 2013; Schierl et al., 2009). Alternatively, based on the results of biomonitoring results (CP levels in the urine of nurses), surface TGVs for CP were suggested to be 0.1 ng/cm2 (the acceptable surface concentration safe for work) and 10 ng/cm2 (prohibitory value triggering stop of the work and remediation actions) (Sessink, 2011). Further, it was suggested that for CP, which is a confirmed carcinogen class I (IARC; European Commission, 2019), the contamination below 1 ng/cm2 should be protective for the health care personnel (Gabay, 2014).
The most relevant uptake route of ADs into the professional staff is the transdermal absorption after the skin contact with contaminated surfaces (Kromhout et al., 2000; Power et al., 2018). Correspondingly, wearing personal protective equipment such as gloves is the most important risk mitigation measure. In addition to skin contact with contaminated surfaces, other routes of exposure have been found highly relevant in the healthcare setting including handling bedding with sweat and body fluids of the patients (Fransman et al., 2005; Hon et al., 2015; Meijster et al., 2006).
In recent years, the administration of chemotherapy is shifting from controlled hospital healthcare that complies with recommended safety regulations (NIOSH, n.d.) (ISOPP 2007) to much less controlled setting such as outpatient departments (where the patients spent only a few hours) or to households of the patients. Typically, 80% of total ADs are administrated intravenously - mostly in hospitals or other medical facilities, about 20% can be administered orally (Kümmerer et al., 2016), and various types of take-home anticancer therapies have become a standard for many patients because of the reduced costs and higher patient satisfaction (Pardhan et al. 2021).
However, the information about the occurrence and levels of ADs outside of the hospitals or pharmacies, i.e. the contamination of surfaces in patient homes are very rare. To our knowledge, there are only three studies that quantified AD contamination in households. Pilot studies from Japan monitored CP and 5-FU in home environments (Yuki et al. 2013), and further extended towards biomonitoring of patients and their family members (Yuki et al., 2015). Also, another study addressed contamination and risks of CP, FU, and Pt residues to families of oncology patients (Böhlandt et al., 2017).
The objectives of the present study were to provide an in-depth research of surface contamination by ADs inside homes focusing on the households of oncology patients (repeated samplings at 17 ambulant oncology patients receiving different chemotherapies), where CP, FU, Pt, doxorubicin (DOX), epirubicin (EPI), IRI, PX were monitored during active chemotherapy, and also after an extended period of six or more months after the last chemotherapy treatment. Further, the present study included a screening of contamination by twelve ADs (CP, FU, Pt, PX, DOX, EPI, IRI, capecitabine (CAP), MET, docetaxel (DOC), GEM) in 2 hospices and 3 retirement homes to get the first insights into potential secondary exposures of the clients and nursing staff.