Antineoplastic drugs in surface waters: presence, exposure, and risk.

Antineoplastic drugs are highly toxic pharmaceuticals used during chemotherapy. Their presence in surface waters has been reported worldwide, increasing environmental and human health concerns. This work estimates the risks from the exposure of humans to antineoplastic drugs via surface waters in a worldwide perspective. Three different scenarios were considered: (i) dermal contact with surface waters, (ii) accidental ingestion of surface waters and (iii) drinking potable water captured from rivers, assuming no further degradation. All but tamoxifen, for which an extraordinarily high average dermal absorbed dose (〖AD〗_abs) was found, the 〖AD〗_abs were always lower than the average daily potential dose (ADD), whether ingested inadvertently or voluntarily (potable water produced from contaminated surface water). To determine whether there would be any risk for humans from their exposure to antineoplastic drugs, the 〖AD〗_abs and ADD were contrasted with the Permitted Daily dose (PDE). The third exposure scenario revealed these compounds’ presence in worldwide surface waters could represent a risk to children, if the highest concentration reported worldwide for cyclophosphamide in surface waters is considered. Even for the remaining antineoplastic drugs/exposure settings, health hazards might arise from synergistic effects and/or prolonged exposures.