Drugs of abuse in tap water from eight European countries: Determination by use of supramolecular solvents and tentative evaluation of risks to human health

[Display omitted] •A preliminary risk assessment of human exposure to drugs of abuse in EU is reported.•Twelve drugs of abuse were analysed in 119 tap water samples from eight EU countries.•Frequency detection was 60.5% and concentrations ranged from 0.3 to 340 ng/L.•Exposure for adults and children was 0.0064–3.531 and 0.0247–6.7580 ng/kg/day.•The inadvertent consumption of drugs of abuse from tap water deserves attention. Recent research findings have confirmed the presence of illicit drugs in tap water from some European Union (UE) member states. Contaminants in tap water come directly from drinking water sources such as rivers or lakes owing to inefficient removal at wastewater treatment and water purification plants. This work was aimed at setting a starting point for assessing the health risks of exposure to twelve drugs of abuse through consumption of tap water in the European population. For this purpose, a method using supramolecular solvents (SUPRAS) was developed to extract drugs in the opioid, amphetamine, cocaine and cannabinoid groups from tap water for their determination by liquid chromatography–tandem mass spectrometry (LC–MS/MS). A total of 119 tap water samples were collected from eight EU countries for analysis. Seven drugs were found at concentrations from 0.3 to 340 ng/L in 72 of the samples (60.5%). The mean exposure to the drugs through consumption of tap water was calculated to be 0.0064–3.531 ng/kg·day for adults and 0.0247–6.7580 ng/kg·day for children, whereas that resulting from dermal contact was estimated to be 4–7 orders of magnitude lower. Exposure values were compared with the minimum required performance levels (MRPL) for the drugs in urine set by the World Anti-Doping Agency (WADA). Based on the results, a need clearly exists for further research into the adverse effects on health of inadvertent, sustained exposure to low doses of drugs of abuse.