6 March 2019

Prof. Tamar Kohn

“Enteric viruses (e.g., rotavirus) are frequently present in recreational water and drinking water sources. We study the fate of these viruses in the environment and during water treatment. Why can some viruses persist over months while other, similar ones quickly die off? Which viruses are easily disinfected and which ones are resistant?”

Lake Geneva water in St. Sulpice. Unlike in many other countries, Switzerland does not disinfect wastewater to control pathogen dissemination into the environment. Professor Tamer Kohn’s research focuses on waterborne pathogens and their fate in the environment and during water treatment. St. Sulpice, June 2017
Tamar Kohn, 44, Associate Professor of Environmental Chemistry in the School of Architecture, Civil and Environmental Engineering (ENAC). The focal point of her research is the degradation of chemical pollutants and inactivation of pathogens in aquatic systems. Its economic and societal goal is to ensure the quality of our water resources, and thereby minimize the occurrence of waterborne disease. St. Sulpice, June 2017
Petri dish with virus plaques. The purple contrast liquid helps the scientists to spot the infective viruses. EPFL, Lausanne, June 2017
An artificial sun blasts strong light on a water sample contaminated with viruses. Prof. Tamar Kohn and her team try to understand how sunlight inactivates these viruses, and why some viruses can resist the disinfecting power of sunlight. EPFL, Lausanne, June 2017
A giant display board showing a satellite view of Lausanne and nearby Lake Geneva decorates the hallway near Prof. Tamar Kohn’s office. EPFL, Lausanne, June 2017
Wastewater flowing through a channel before reaching a sedimentation basin. Samples of this sewage water will be collected by Prof. Tamar Kohn’s team and analysed for waterborne pathogens. STEP Ecublens, June 2017
Charles Gan, 22, at the fume hood, infecting cells with pathogenic viruses found in wastewater. The cells infected by viruses will die and are easily identifiable by microscope. EPFL, Lausanne, June 2017
A lab rocker is used for low foaming agitation, RNA extraction, washing and various staining procedures. Here, water samples of the wastewater plant are being prepared for further analysis. EPFL, Lausanne, June 2017
A soft toy of an Escherichia coli, or E. coli, bacterium. Many strains of E. coli are harmless, and large numbers are present in the human and animal gut. Nevertheless, pathogenic strains of E. coli can also escape the confines of the human and animal intestinal tracts and cause both urinary and serious abdominal infections. E. coli excreted in feces can contaminate water resources through runoff or improper sewage treatment. For example, raw vegetables irrigated by contaminated water are common E. coli offenders. EPFL, Lausanne, June 2017
Prof Tamar Kohn’s office. A poster of children playing happily in a pool in a pool serves as a reminder that good water quality is an important societal goal that affects more than just our diet.  EPFL, Lausanne, June 2017
Dead cells infected by viruses seen through the microscope. A virus cannot be seen on optical microscopes, but the remains of dead cells can indicate its presence. EPFL, Lausanne, June 2017