Sewage analysis reveals holiday spike in drug use

Researchers analysed samples taken from the inlet of wastewater treatment plants at three different areas in south-east Queensland.

Consumption of cannabis, cocaine, ecstasy (MDMA) and methamphetamine was estimated in a large coastal urban area, an inland semi-rural area and an island with a small resident population predominantly populated by holidaymakers during the peak summer holiday period including Christmas and New Year.

The researchers, from the University of Queensland, showed that cannabis was the most commonly used ‘everyday’ drug at around 1000–2000mg/day/1000 people.

Weekend use of cocaine was about 20–200mg /day/1000 people and 5–50mg /day/1000 people for MDMA but this doubled in the holiday season in the urban and semi-rural area and at least tripled on the resort island.

The researchers estimated the changes in drug use with a statistical measure of effect size called ‘Hedges’ g