Analysis of waste sheds light on lockdown habits

Crises tend to have a drastic effect on our way of life, affecting how much alcohol or coffee we drink or how many cigarettes we smoke, what kind of medicine we take and in what doses, what kinds of narcotics we abuse and how many chemicals we use. The coronavirus pandemic, needless to say, has left its own distinct imprint on the habits of Greeks since it first appeared in the country in late February.

An analysis of sewage from the Attica region earlier this summer has shown that, for example, cocaine use increased to unprecedented levels during the first wave of the pandemic compared to pre-Covid times. Greeks also consumed as much cannabis as they did nicotine, while using an enormous amount of antiviral medication and disinfectants. The use of antibiotics and antidepressants shot up too, as did the quantities of pain relief medicine consumed. In the meantime, widespread discussion about the negative effects of blood pressure medicine and non-steroidal anti-inflammatory drugs on Covid-19 triggered a significant reduction in their use.

Professor of analytical chemistry Nikolaos Thomaidis and his team at Athens University have spent a decade studying the thousands of chemical compounds and organic elements in human waste that makes its way from the broader area of the Greek capital to the biological sewage treatment plant at Psyttaleia.

The scientists are now using advanced methods of wastewater-based epidemiology, “a new, objective and non-invasive tool of analytical chemistry,” according to Thomaidis, and getting impressive results.

“We can extract results from the chemical compounds we study not just on the health and habits of the residents of the Attica Basin, but also on how these relate to social and economic situations such as the economic crisis, unemployment or, right now, the Covid-19 pandemic. In the first five years of the economic crisis, in 2010-14, for example, we observed a dramatic rise in psychiatric medications. Residents were using 35 times more neuroleptics, 19 times more sedatives and 11 times more antidepressants,” he explains.

The findings made as a result of testing on samples taken by Thomaidis’ team since early March, in cooperation with the Sewerage Department of the Athens Water Company (EYDAP), are also fascinating.

“We have recorded a leap of 169% in the use of antiviral medication. What is particularly interesting is the combination of at least seven antiviral drugs that were used to combat Covid-19, along with much-touted hydroxychloroquine, which rose 387% and is normally used to treat rheumatism and malaria. Antibiotics use also rose 15%, while consumption of the antibiotic azithromycin doubled, as it was the medicine that was being regularly prescribed by hospitals during the first wave of the pandemic,” says Thomaidis.

The researchers also found a rise in the use of the antidepressants citalopram and venlafaxine, with Thomaidis pointing to some interesting results from the comparison of their use before the economic crisis. “They rose sharply in 2014-15 and then fluctuated, but their use never returned to pre-2010 levels,” he says.

Detergents were found in much greater quantities in the recent analyses too, and particularly quaternary ammonium compounds used in industrial cleaners. Specific surface cleaning agents were also abundant as a result of the increased sterilization of often-touched surfaces in both private homes and public areas. “These levels remained very high even after the virus initially subsided,” says Thomaidis.

The findings concerning drug use are quite startling as well, as traces of cocaine rose to more than 800 grams a day, or 67% above the 2019 daily average. “This is the biggest increase we have seen since 2010,” says Thomaidis, adding that compared to 2019, the use of amphetamines rose 650%, methamphetamines 37% and ecstasy by 38%.

When the quantities are described in terms of their weight, the findings are even more impressive to the lay person. For example, on a daily basis, the Psyttaleia plant receives 2.6 kilograms of anti-depressants (from 1.8 kg pre-Covid), 22 kg of antibiotics (from 17 kg), 55 kg of blood pressure medicines (chiefly 43 kg of valsartan), 155 kg of cannabis (from 185 in 2019 and 422 in 2015) and 11 kg of analgesics (from 5.6 kg pre-Covid).

The findings also show a small increase in caffeine consumption at 16 kilograms a day from 15 kg last year, but a decrease in nicotine use, at 113 kilograms a day from 183 kg in 2019.

On a daily basis, the Psyttaleia waste treatment plant processes thousands of kilograms of surface cleaners, laundry detergents and other products of everyday use, as well as medicines, drugs and industrial chemicals.

“It is worth noting that many of these elements cannot be removed with the current technology used in biological waste treatment and, of course, end up in the natural environment. A joint study by the University of Athens and EYDAP found that, every day, hundreds of kilograms of medical and narcotic substances and their metabolites, as well as sweetening agents, caffeine and industrial chemicals end up in the Saronic Gulf,” says Thomaidis.

“This is a global problem, of course. Biological waste treatment plants were not designed to remove all the synthetic chemicals produced and used by man. This calls for a new approach, the development of fourth generation treatment plants, which is, however, extremely expensive. If we want zero chemicals to end up in the marine environment, the chemistry needs to be green and the chemical compounds biodegradable,” he adds.