Water securityBrazil’s sewage woes reflect the growing global water quality crisis

By Joan Rose

Published 11 August 2016

All eyes are turned toward Rio de Janeiro to watch top athletes compete, yet the headlines continue to highlight the problems with the water quality and the risks to the athletes who swim, row, and sail, and even to tourists simply visiting the beaches. But Brazil’s wastewater woes are hardly unique. The water quality of lakes, rivers, and coastal shorelines around the world is degrading at an alarming rate. In fact, pollution of the ten largest rivers on earth is so significant that it affects five billion people. While the spotlight is shining on the athletes over the next few weeks, let us also shine a spotlight on what we can do to improve and restore water quality around the world through our collective efforts, use of new tools, and risk frameworks, moving the political will one step closer toward sewage treatment and protection of the biohealth of the blue planet.

Joan Rose, Michigan State University // Source: msu.edu

All eyes are turned toward Rio de Janeiro to watch top athletes from all over the world compete. Yet the headlines continue to highlight the problems with the water quality and the risks to the athletes who swim, row, and sail, and even to tourists simply visiting the beaches.

Large concentrations of disease-causing viruses have been found in the aquatic venues, particularly in the Rodrigo de Freitas Lagoon, where Olympic rowing will take place, and the Gloria Marina, the starting point for the sailing races. These viruses — adenoviruses, rotaviruses and noroviruses — are coming from human fecal wastes, untreated and/or inadequately treated sewage, and cause a variety of health problems, ranging from milder symptoms such as headache, respiratory infection, or diarrhea to severe illness impacting the heart, liver and central nervous system.

But Brazil’s wastewater woes are hardly unique. The water quality of lakes, rivers, and coastal shorelines around the world is degrading at an alarming rate. In fact, pollution of the ten largest rivers on earth is so significant that it affects five billion people.

One of the root problems in Rio and other places is how water quality is tested. Monitoring for a broader set of viruses and other microbes in water would be a big step in improving public health.

Beyond e.coli testing
Human fecal waste remains one of the most important sources of pathogens. Today, water quality is most often measured by testing for E.coli bacteria, and this is the standard used around the world. But we have better ways to identify the microbes that cause problems when pollution, such as sewage, is released in our rivers, lakes and shorelines.

In my own research, my colleagues and I have tested for the presence of an alternative virus (known as the coliphage) as an inexpensive indicator for evaluating sewage treatment. We also use a whole variety of other tests which allow us to monitor for specific pathogens including viruses.

Our analysis and others suggest we should be striving at a minimum for 99.9 percent reduction of viruses by the variety of sewage treatment designs. If we rely on testing only for E.coli bacteria, we won’t be able to remove viruses.