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.

Flame-retardants (FR) are a group of anthropogenic environmental contaminants used at relatively high concentrations in many applications. Currently, the largest market group of FRs is the brominated flame retardants (BFRs). Many of the BFRs are considered toxic, persistent and bioaccumulative. Bioremediation of contaminated water, soil and sediments is a possible solution for the problem. However, the main problem with this approach is the lack of knowledge concerning appropriate microorganisms, biochemical pathways and operational conditions facilitating degradation of these chemicals at an acceptable rate. This paper reviews and discusses current knowledge and recent developments related to the environmental fate and impact of FRs in natural systems and in engineered treatment processes.

Changes in the microbial community composition of a full-scale membrane bioreactor treating industrial wastewater were studied over a period of 462 days using a series of 16S rRNA gene clone libraries. Frequent changes in the relative abundance of specific taxonomic groups were observed, which could not be explained by changes in the reactor's conditions or wastewater composition. Phage activity was proposed to drive some of the observed changes. Bacterial hosts were isolated from a biomass sample obtained towards the end of the study period, and specific phage counts were carried out for some of the isolated hosts using stored frozen biomass samples as the phage inocula. Plaque-forming unit concentrations were shown to change frequently over the study period, in correlation with changes in the relative abundance of taxonomic groups closely related by 16S rRNA gene sequence to the isolated strains. Quantitative PCR was used to verify changes in the abundance of a taxonomic group closely related to one of the isolated hosts, showing good agreement with the changes in relative abundance in the clone libraries of that group. The emerging pattern was consistent with the ‘killing the winner’ hypothesis, although alternative interaction mechanisms could not be ruled out. This is the first time that phage–host interactions in a complex microbial community are demonstrated over an extended period, and possibly the first in situ demonstration of ‘killing the winner’ stochastic behavior.