Study shows drug residues in wastewater from educational institutions

Ljubljana – A study by a group of researchers at the Jožef Stefan Institute (IJS) determined the content of drugs in wastewater samples from Slovenian educational institutions. The results showed that nicotine, alcohol and cannabis were the most prevalent drugs, while residues of morphine, codeine and cocaine were detected as well.

Researchers from the Environmental Sciences Division of the Jožef Stefan Institute (IJS) used samples of wastewater from Slovenian primary and secondary schools and higher education institutions to carry out their study.

It aimed to determine the presence of metabolic products of legal drugs (nicotine and alcohol), abused drugs (morphine, codeine and methadone) and illegal drugs (cannabis, cocaine, amphetamine, methamphetamine, ecstasy and heroin), the IJS said in a press release.

The study covered 44 educational institutions offering different levels of education, selected from both urban and non-urban areas in 7 Slovenian municipalities across 6 statistical regions.

The results on drug prevalence were compared by education level, geographical location and the level of urbanisation.

The survey shows that nicotine, alcohol and cannabis are the most widely used drugs overall, with alcohol and cannabis having comparable prevalence despite the difference in availability.

Among the abused drugs, researchers identified biomarkers for morphine and codeine, while methadone biomarkers were below the limit of detection. Among stimulants, cocaine was the most prevalent.

Nicotine, alcohol, cannabis and cocaine were present in wastewater samples from educational institutions in all seven municipalities.

Meanwhile, biomarkers for all target drugs (except methadone and heroin) were identified only in Ljubljana, the study shows.

The study also showed a correlation between cocaine use/availability and urbanisation, while simultaneous use of alcohol and cocaine was only determined in samples from urban areas.

As explained by the IJS, the results indicate the presence of drugs that were not necessarily ingested in educational institutions, as the metabolic products of drugs take longer to be excreted in the urine.

In addition, the school environment is not only comprised of students, but also teachers, support staff and visitors, who may also contribute to the occurrence of certain biomarkers in wastewater, said the IJS.