Coronavirus concentration in waste water has decreased to moderate or low level across Estonia, the latest results in a regular study led by the University of Tartu shows, while no town of over ten thousand inhabitants – which is around 14 towns home to more than half the nation's populace – has significant levels in its wastewater.
Head of the study, Professor Tanel Tenson, says the falling rates are also evident in the major towns in Ida-Viru county, where rates had previously been high, and are now moderate.
Whereas just a week ago the interactive map of surveillance results still displayed several places in dark red, which referred to very high virus amounts, the results of the recently ended stage of the study are marked in green or yellow in nearly all places, the university says (see graphic below).
This demonstrates a predominantly small or moderate level of coronavirus in waste water.
The study involves collecting wastewater samples at the beginning of each week in population centers of 10,000 inhabitants or more (of which there are about 15), and in smaller settlements where necessary, the university says.
In the case of the larger cities, the data reflects wastewater passing through a treatment plant over a 24-hour period, which it says provides an accurate overview, whereas in smaller population centers, spot checks are conducted, which need to be used over several weeks to get a clear picture of trends, due to their greater susceptibility to various factors.
The survey is conducted in conjunction with the relevant water service providers and the Estonian Environmental Research Center, while samples are analyzed at the University of Tartu Institute of Technology.
More info (in Estonian) is here.
The previous week's survey results are reported here.
Editor: Andrew Whyte