Dr Kim Summers, Research Fellow, School of Life Sciences at The University of Warwick said, “The pollution seen in the Seine in Paris is sadly all too common in rivers across the world. The recent heavy rainfall will have made things worse, as France, like many other countries has a combined sewer system. This means that heavy rain mixes with sewage waste and the sheer volume can overwhelm sewage treatment plants, causing overspills. Of particular concern are gut associated bacteria, such as E. coli, both because they are markers of contamination by faeces and because some can be dangerous pathogens, causing serious illness.

“The levels of bacteria are being monitored daily and there are long-term measures being put in place, such as a reservoir to hold excess sewage waste flow. But in the short-term there is little that can be done, but wait, watch, and hope for levels to fall. What is particularly disappointing is that this was a known risk for a long time and the organisers do not seem to have appropriate contingency measures in place, such as a backup venue.”