Prevalence of illicit drugs and pharmaceuticals in environmental waters – A global spatial review

• Similar pharmaceutical and illicit drug levels seen in North America and Europe • Europe had the highest prevalence of cancer medications and hallucinogens • North America had a high prevalence of cannabinoids, anti-asthmatics, and hormones • South America recorded elevated concentrations of cocaine and derivatives • Africa and Asia recorded the highest concentrations of 16 pharmaceuticals The contamination of environmental waters with pharmaceuticals and illicit drugs is an escalating global concern amidst growing water scarcity and pollution challenges. The study of the prevalence of substances in environmental waters not only provides an understanding of environmental pollution but also informs consumption patterns and possible trafficking routes. Despite growing concern over pharmaceutical and illicit drug contamination in aquatic environments, current literature lacks a comprehensive global spatial synthesis across wastewater and surface water systems. This study addresses that gap by systematically analysing the distribution of 26 substance groups across six continents, providing the first global-scale spatial comparison of environmental concentrations derived from 400 peer-reviewed articles. The study found that Africa exhibited the highest overall median concentration across all substance groups (7.09 × 10 2 ng/L), followed by Oceania (3.28 × 10 2 ng/L), South America (1.30 × 10 2 ng/L), North America (9.00 × 10 1 ng/L), Europe (9.00 × 10 1 ng/L), and Asia (4.42 × 10 1 ng/L). Notably, stimulants and painkillers dominated influent wastewater, while anti-convulsants and anti-inflammatories were prevalent in effluent wastewater. Surface waters showed significant presence of anti-inflammatories and antibiotics. These findings not only illuminate global consumption and disposal trends but also offer critical insights for shaping water treatment policies and public health strategies. The study underscores the pressing need for harmonized monitoring frameworks to mitigate pharmaceutical and drug pollution across diverse ecological contexts.