Alcohol remains the most commonly consumed psychoactive substance in Australia with approximately 15 litres of ethanol consumed per 1000 people per day. It is one of the most harmful drugs in Australia accounting for 4.5% of the total burden of disease. The top 10% of drinkers consume over half of all alcohol and are responsible for the majority of the alcohol-related harm. Specifically, the Northern Territory has the highest proportion of lifetime risky drinking; single occasion risky drinking at least monthly; and the highest level of alcohol-related harm.
In October 2018, to combat alcohol-related harm, the Northern Territory implemented a suite of interventions to reduce supply including a minimum unit price (MUP) for alcohol purported to reduce the ability of heavy drinkers to purchase large amounts of alcohol cheaply.
The aim of this study was to assess the impact of these interventions in the Northern Territory based on wastewater analysis.
Samples were collected bimonthly (in capital cities) and quarterly (in regional places) as part of the National Wastewater Drug Monitoring Program between August 2016 and February 2020 across 66 sites nationwide. Standard drinks consumed per day per 1000 people in the respective catchments were estimated based on the concentration of an alcohol specific metabolite ethyl sulfate in the wastewater, its excretion factor, the flow of wastewater entering the wastewater treatment plants and catchment populations.
Results from a linear mixed model showed that alcohol consumption significantly decreased in the Northern Territory after the introduction of a MUP (a decrease of 800 standard drinks per day per 1000 people) and this change was significantly larger than any other state/territory.
We concluded that per-capita consumption of alcohol decreased after the implementation of a minimum unit price and that wastewater analysis is a viable method for measuring the impact of interventions on a community.