The latest round of tests on the waters around Rio de Janeiro reveal it is even more extensively contaminated than had been supposed, adding further to fears it will be impossible to guarantee the safety of water sports competitors in next year’s Olympics.
An initial set of tests by AP in July revealed that the levels of adenoviruses in Guanabara Bay were up to 1.7 million times higher than what US and European authorities consider safe for bathing. Also present – though in lesser quantity – were unusually high levels of fecal coliform bacteria, associated with typhoid and cholera.
The new tests – also conducted by AP who published the results in late November – show the waters over a kilometre from the shore registering similar virus levels to those located near sewage sources at the shoreline. Concerns for the safety of sailing competitors – events that will run at this kind of distance from the shore – were a focal point of media reports about the new test results.
In August German sailor Erik Heil came down with a bacterial skin infection following a training event in Guanabara Bay, and required daily hospital treatment. He believed it to have been caused by the water. Infectious disease experts suggested this was unlikely, as MRSA is normally only transferred by skin to skin contact.
An expert in waterborne viruses at the University of Texas, Kristina Mena, said the measured virus levels constituted an “extreme environment, where the pollution is so high that exposure is imminent and the chance of infection very likely”, as reported on the website phys.org.
The source of the pollution is raw, untreated sewage flowing directly into the bay. In Brazil, sewage treatment is still the exception rather than the rule, and most of it is discharged into open-air ditches feeding into streams and rivers, such as those feeding into Guanabara Bay.
Rio’s bid to host the 2016 Olympics partly rested on pledges to clean up the city’s sewage system, which appear to have remained unfulfilled.
Oceanography professor David Zee of Rio State University told Business Insider that the problem has been getting progressively worse for decades. Advocating for the adoption of more extensive river treatment systems, to tackle the problem before water reaches the bay, he suggested that such approaches present a conundrum with respect to who should pay for it.