The 2016 Olympics opened in Rio de Janeiro on Friday, with a ceremony celebrating Brazil’s diversity, its – often controversial – history and, looking ahead, its commitment to an environmentally responsible future. And for a games that had already weathered budget cuts and well-publicised doping controversies before athletes had even stood in the blocks, it was the contagious enthusiasm of cariocas for their moment in the global sporting sunshine that shone through.

Contagions, however, have also been much on the mind of athletes and organizing authorities in recent months. The threat of the Zika virus has cast a modest shadow over the games; golf’s return to the Olympic fold after a 112-year hiatus was dampened by the news in June that World Number 1 Rory McIllroy would be among several on the PGA tour not competing in Rio, nominally due to the mosquito-borne disease.

Likewise, USA Women’s Soccer Goalkeeper Hope Solo took to Twitter, posting pictures of her brimming arsenal of insecticides and posing in a costume that even a well-dressed beekeeper might find excessive. Predictably, the impromptu photoshoot drew the mockery of local fans during the USA’s opener against New Zealand.

Some have gone so far as to brand the McIlroy abstention ”extreme”, with even the director general of the World Health Organization stepping in to assert that the risk posed by Zika to athletes is low.

But what few can ignore are the hazards faced by any athlete bold enough to dip their toes in one of Rio’s open-water aquatics venues – Guanabara Bay and the Rodrigo de Freitas Lagoon.

As part of the bidding process, state and city authorities had pledged to embark on a major cleaning operation, promising that the games would “rejuvenate Rio’s waterways”. And the city was certainly crying out for it – over the past few decades, many of the 55 rivers flowing into Guanabara Bay have been successively declared “dead” by scientists.

But despite the vows, levels of pollutants – industrial effluent, landfill runoff and raw sewage – have remained stubbornly, and deplorably, high. Water samples taken in the last month have revealed extreme levels of pollution, with one test weighing in at 1.7 million times the admissible limit in the USA, a country not normally noted for its environmental sensitivity.

For those at the games, this state of affairs has been a mixed blessing; while the world’s press have been falling over each other to snap lurid shots of semi-submerged corpses for gleeful picture editors, one can only assume that actual participants in aquatic events met with a shudder news that ingesting a mere 3 teaspoons of water could lead to serious illness.

So spare a thought for Serbia’s men’s rowing pair, capsized in choppy conditions on the Lagoa Rodrigo de Freitas.

Meanwhile, organizers are investigating reports that competitors in a kayaking warm-up event were torpedoed by a rogue sofa. The veracity of the story has yet to be established, but the sofa in question has taken to Twitter, presumably seeking to capitalize on its 15 seconds in the sporting spotlight.

ADDENDUM: But why should Brazil have all the fun? The enthusiasm for all things athletic has spread to Peru, with newly-elected president Pedro Pablo Kuczynski hosting his first cabinet meeting over a 25 minute gym class with his ministerial subordinates. The stunt comes as part of an initiative to promote healthy living among Peruvians, and one can only assume that the electorate, who helped the 77 year old former World Bank economist squeak home in April’s election, hope he will pursue his promised “social revolution” with similar vigour.