ATHENS – Looking for clues everywhere on how to deal with a second wave of COVID-19, chemists studying the Greek capital’s sewage system figured out that some half million people left during a lockdown over the holidays.

The government said travel would be restricted but there was no explanation why people apparently were able to get around it although police were said to be out in force looking for violators.

“We observed a decline in the use of the sewage system… from an average of 3.7 million users earlier in December to 3.2 million over a 10-day period (December 21-30) during the holidays,” Nikos Thomaidis, Professor of Analytical Chemistry at Athens University told Kathimerini.

Greek scientists had routinely been analyzing waste loads to check for signs of infections but this time discovered travel routines as well with Thomaidis’ team started checking samples from the Wastewater Treatment Plant on the islet of Psyttalia in March, and since early September has been conducting tests daily.

Analysis of the viral content of the waste is a good predictor of whether infections will spike or decline and provides a more accurate picture of the real spread of the infection that has been surging, the paper also noted.