麻豆社

Dr Daniel Becker, a paediatrician who works in the city's poorest neighbourhoods, says "human sewage", combined with industrial waste, in Guanabara Bay pose a real risk to swimmers, sailors and windsurfers.

He said Brazil's government has used "band aid tricks" to reduce the amount of rubbish, but this is a much bigger problem than that.

If athletes on, or in the water swallow any of it, Dr Becker says the bacteria and viruses contained within could lead to "diarrohea, vomiting, gastrointestinal disease, also Hepatitis A is a risk."

This clip is originally from the Duncan Barkes programme on Saturday 30th July 2016.