Pholedrine is a marker of direct disposal of methamphetamine

Consumption of methamphetamine has primarily been estimated in wastewater-based epidemiology by measuring the parent compound. However, this could lead to overestimation when methamphetamine is directly disposed into the sewer system. In this respect, it would be advantageous to measure a specific metabolite of methamphetamine instead. We identified 4-hydroxymethamphetamine (pholedrine) as a potential marker. Stability experiments were performed in both filtered and unfiltered wastewater. Correlations with relative loads in wastewater were used to establish its potential as a marker of direct disposal of methamphetamine, or even as a wastewater-based epidemiology biomarker of methamphetamine consumption. This study then investigated the use of pholedrine in combination with methamphetamine to better detect direct disposal events and its potential as a marker of methamphetamine consumption. Examples from both South Australia and New Zealand exemplify the use of pholedrine to identify potential instances of direct disposal of methamphetamine.