High cocaine levels in wastewater post-rugby

Rugby supporters gathered outside a pub in Cardiff city centre
The highest levels of absorbed cocaine found in waste water was during autumn internationals [Getty Images]

High levels of absorbed cocaine have been found in south Wales' waste water, according to a new study.

The largest consumption was found to have peaked during rugby internationals in Cardiff in 2021, when Wales faced South Africa, which found 8.54 milligrams of the illegal drug per day, per 10,000 people.

By comparison, the two other sites recorded levels of just 3.88 milligrams and 1.97 milligrams per day, per 10,000 people.

A spokesperson for Public Health Wales said the study coincides with the increasing cocaine use they have seen in recent years and highlights the benefits of identifying drug use trends.

The study set out to understand the levels of use of new psychoactive substances in south Wales and was carried out by Bournemouth university's analytic research group.

But the main substance detected in wastewater samples was benzoylecgonine, a compound that is produced when the body breaks down cocaine.

The first study of its kind in Wales, it looked at samples before and after being purified, from Friday to Monday every week, over a two-month period.

PhD student Bethan Davies, who led the study, said the Wales v South Africa rugby weekend seen a significant increase of footfall, where absorbed cocaine was at its highest across the study.

Despite the public health concern, Ms Davies said the development could help in addressing drug monitoring and improving treatment.

"By knowing what is popular within certain communities, we can tailor how we test for substances in different areas and avoid spending time and resources testing for drugs that are not around," said Ms Davies.

Picture of Bethan Davies, the lead of the study
Bethan Davies, who led the study, says community led testing can help improve health and social services [Contributor photo]

On average, 73% of benzoylecgonine was removed during treatment, meaning traces remained in the water that went back into the region.

But Welsh Water confirmed that the post-treated wastewater is not forwardly used for drinking, but for non-consumption use such as toilets and laundry.

Ms Davies also confirmed that if the wastewater was consumed post-treatment, the levels should not cause any issues to public health.

Dr Giri Shankar, director of health protection for Public Health Wales, said the study highlights the benefits of identifying drug use trends.

"The findings are consistent with our own research, which shows a trend of increasing cocaine use in recent years," he said.

"We have monitored an increase in the number of assessments for cocaine, including crack, by substance misuse services in Wales.

"The number of deaths from drug-related causes remains unacceptably high in Wales.”

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