Wastewater of an Australian campus of 30,000 shows a rise in oxidative stress marker 8-OHG during exams

Researchers analysed wastewater samples collected in 2022 from an Australian university campus of about 30,000 people, according to a study published on nature.com nature.comnature.comnature.comOpen source ↗. The samples were tested for oxidative stress biomarkers, antidepressants, attention deficit hyperactivity disorder (ADHD) medication and behavioural indicators. Temporal patterns during the examination period were compared with teaching periods.

A general-population catchment of about 120,000 residents, sampled at the same time, served as a reference. The authors note that population-level monitoring of student stress usually relies on self-reports or prescription data, which have limited temporal resolution.

Oxidative stress markers and medication

Difference-in-differences analysis showed a marked university-specific increase in 8-hydroxyguanine (8-OHG) during the examination period. Evidence for a rise in 8-hydroxy-2′-deoxyguanosine (8-OHdG) was weaker. Both compounds are oxidative stress biomarkers.

Antidepressant consumption showed consistent positive trends during the examination period, but these were not statistically significant nature.comnature.comnature.comOpen source ↗. Ritalinic acid and amphetamine, which are markers of ADHD medication, remained relatively stable.

Behavioural indicators

The behavioural panel included alcohol, nicotine and tobacco biomarkers, paraxanthine (a caffeine biomarker) and acesulfame. Alcohol, total nicotine and tobacco-derived nicotine remained relatively stable between teaching and examination periods. Paraxanthine and acesulfame decreased significantly.

What the authors conclude

The study combined several biomarkers in one analysis, covering oxidative stress, medication and behaviour. According to the authors, this makes wastewater surveillance a non-invasive and complementary tool for identifying periods of increased mental health burden in university populations and for informing timely public health interventions.

The data describe the campus population as a whole rather than individuals, and come from one campus in one year. Only the 8-OHG increase was clearly marked; the antidepressant trends were consistent but did not reach significance nature.comnature.comnature.comOpen source ↗.