Monitoring of ethyl sulfate biomarker for the estimation of community alcohol consumption via wastewater using a direct injection method

Wastewater-based epidemiology provides an objective and complementary means of monitoring community alcohol consumption by measuring alcohol biomarkers excreted by the population. This approach enables the assessment of temporal and regional trends, offering valuable insights into consumption behavior and its public health implications. In this study, a previously established analytical method based on liquid chromatography-tandem mass spectrometry for the quantification of ethyl sulfate was re-optimized to enhance sensitivity and reduce analysis time, ensuring its effective applicability for routine monitoring. The improved direct injection method was validated and successfully met all analytical performance criteria. It was then applied to wastewater samples collected from a treatment plant across four seasons in 2019, 2020, and 2021 to estimate population-level alcohol consumption. Mean annual consumption ranged between 0.62 and 87.84 L/day/1000 inhabitants. A pronounced decline in estimated alcohol use was observed within the catchment area served by the monitored wastewater treatment plant over the monitoring years, potentially associated with the combined influence of the COVID-19 pandemic and increased alcohol taxation. These findings highlight the value of WBE as a cost-effective, non-invasive, and population-level tool that complements conventional epidemiological and sales data, providing real-time evidence to support alcohol-related public health strategies and policy development.