BENGALURU: A majority of the COVID-19 hotspots identified by the BBMP are found to be near sewage treatment plants (STPs), observed Dr V S Prakash, hydrologist and former founder-director of Karnataka State Natural Disaster Monitoring Centre. “This cannot be sheer coincidence that majority of the wards, which have been identified as hotspots in Bengaluru, are near the STPs of Koramangala- Chalaghatta (KC), Hebbal- Nagwara (HN) and Vrishbhavathi Valleys.
We need to find out if there’s any correlation between incidents of infection and sewage water. Urban areas re-use sewage water, which has undergone primary and secondary treatment for non-potable purposes,” said Dr Prakash. The BBMP last week had identified 32 wards as hotspots. Some initial studies done overseas have suggested the presence of nCoV in wastewater, he said.
“In France, traces of the novel coronavirus were discovered in 4 out of 27 samples of the non-potable water, which is supplied in Paris. The supply network of non-potable water was immediately shut down as a measure of precaution,” he said.
“Not just France, the presence of virus in wastewater is being reported from other countries as well. This can be scientifically studied and used as a prognostic tool for tracking and monitoring of the spread of COVID-19,” he added. On April 20, the Central Pollution Control Board, issuing the guidelines for handling, treating and disposing of waste generated by COVID-19 patients, said there is no evidence as of now to prove the transmission of COVID-19 through sewerage systems but did not rule out the possibility of transmission of the virus to operators during treatment of STPs. It called for use of Personal Protective Equipment for STP operators.
Late last month, in a large metropolitan area in Massachusetts, traces of SARS-CoV-2 were found at much higher levels in wastewater than expected indicating that a much higher number of people were likely infected with COVID-19 than the cases that were reported in that area. The study conducted by a team from Biobot Analytics, a biotech startup, along with a team from Massachusetts Institute of Technology and Brigham and Women’s Hospital was posted on preprint server medRxiv on April 14. The American website – ‘ScienceDaily’ — had stated that “researchers are working on a new test to detect SARS-CoV-2 in the wastewater of communities infected with the virus.
The wastewater-based epidemiology approach could provide an effective and rapid way to predict the potential spread of novel coronavirus pneumonia (COVID-19) by picking up on biomarkers in faeces and urine from disease carriers that enter the sewer system.” Haizhou Liu, associate professor of chemical and environmental engineering at the University of California, Riverside, and Professor Vincenzo Naddeo, director of the Sanitary Environmental Engineering Division at the University of Salerno, “have called for more testing to determine whether water treatment methods are effective in killing SARS-CoV-2 and coronaviruses in general” in their editorial in ‘Environmental Science: Water Research & Technology’, a leading environmental journal.