Estimating Alcohol Consumption by Wastewater-Based Epidemiology: An Assessment of the Correction Factor for Ethyl Sulfate Using Large-Scale National Monitoring Data

The correction factor (CF) of the alcohol biomarker ethyl sulfate (EtS), an important parameter for back-estimating alcohol consumption via wastewater-based epidemiology (WBE), reportedly has a large uncertainty due to the limited size of relevant pharmacokinetic studies. We applied an alternative approach to derive an EtS CF by comparing the sales data with the total load measured by WBE across Australia. We utilized EtS data from the National Wastewater Drug Monitoring Program in Australia from 2016 to 2019, that covered more than 50% of the Australian population. National sales data for alcohol were obtained from the Australian Bureau of Statistics from 2016 to 2018—the most recent data available. A new CF of 4 × 103 was suggested for EtS, significantly greater than the CFs that have been used previously (3042 or 3320). This new CF was applied to a separate multiple-year set of WBE data for EtS from an Australian town and generated estimates that better match sales data than the previous CFs. The new CF incorporates both the excretion rate and sewer degradation of EtS and hence is likely to improve the future accuracy of alcohol consumption estimates by WBE.