Background and aims: Wastewater‐based epidemiology is an additional indicator of drug use that is gaining reliability to complement the current established panel of indicators. The aims of this study were to: (i) assess spatial and temporal trends of population‐normalized mass loads of benzoylecgonine, amphetamine, methamphetamine and 3,4‐methylenedioxymethamphetamine (MDMA) in raw wastewater over 7 years (2011–17); (ii) address overall drug use by estimating the average number of combined doses consumed per day in each city; and (iii) compare these with existing prevalence and seizure data.Design: Analysis of daily raw wastewater composite samples collected over 1 week per year from 2011 to 2017.Setting and Participants: Catchment areas of 143 wastewater treatment plants in 120 cities in 37 countries.Measurements: Parent substances (amphetamine, methamphetamine and MDMA) and the metabolites of cocaine (benzoylecgonine) and of Δ⁹‐tetrahydrocannabinol (11‐nor‐9‐carboxy‐Δ⁹‐tetrahydrocannabinol) were measured in wastewater using liquid chromatography–tandem mass spectrometry. Daily mass loads (mg/day) were normalized to catchment population (mg/1000 people/day) and converted to the number of combined doses consumed per day. Spatial differences were assessed world‐wide, and temporal trends were discerned at European level by comparing 2011–13 drug loads versus 2014–17 loads.Findings: Benzoylecgonine was the stimulant metabolite detected at higher loads in southern and western Europe, and amphetamine, MDMA and methamphetamine in East and North–Central Europe. In other continents, methamphetamine showed the highest levels in the United States and Australia and benzoylecgonine in South America. During the reporting period, benzoylecgonine loads increased in general across Europe, amphetamine and methamphetamine levels fluctuated and MDMA underwent an intermittent upsurge.Conclusions: The analysis of wastewater to quantify drug loads provides near real‐time drug use estimates that globally correspond to prevalence and seizure data.

A comprehensive analytical investigation of the sorption behaviour of a large selection of over-the-counter, prescribed pharmaceuticals and illicit drugs to agricultural soils and freeze-dried digested sludges is presented. Batch sorption experiments were carried out to identify which compounds could potentially concentrate in soils as a result of biosolid enrichment. Analysis of aqueous samples was carried out directly using liquid chromatography-tandem mass spectrometry (LC-MS/MS). For solids analysis, combined pressurised liquid extraction and solid phase extraction methods were used prior to LC-MS/MS. Solid–water distribution coefficients (K_d ) were calculated based on slopes of sorption isotherms over a defined concentration range. Molecular descriptors such as log P, pK_a, molar refractivity, aromatic ratio, hydrophilic factor and topological surface area were collected for all solutes and, along with generated K_d data, were incorporated as a training set within a developed artificial neural network to predict K_d for all solutes within both sample types. Therefore, this work represents a novel approach using combined and cross-validated analytical and computational techniques to confidently study sorption modes within the environment. The logarithm plots of predicted versus experimentally determined K_d are presented which showed excellent correlation (R² > 0.88), highlighting that artificial neural networks could be used as a predictive tool for this application. To evaluate the developed model, it was used to predict K_d for meclofenamic acid, mefenamic acid, ibuprofen and furosemide and subsequently compared to experimentally determined values in soil. Ratios of experimental/predicted K_d values were found to be 1.00, 1.00, 1.75 and 1.65, respectively.

• Rapid, direct LC–MS/MS of 135 analytes in filtered wastewater demonstrated in 5 min. • Quantitative performance was excellent over several orders of magnitude. • Median limits of detection of 9 ng L−1 with standard injection volumes and flow rates. • Excellent chromatographic definition with ∼20−30 datapoints/peak. • 56 compounds quantified in small samples of raw wastewater from UK, USA and Mexico.