Rio de Janeiro | A Danish Olympic sailor claims to have become pregnant after falling in the waters of the Guanabara Bay, where the sailing competitions will take place next week.

Alvilda Jensen arrived on July 12 to familiarize herself with the local sailing conditions. Undergoing her last medical exam before participating in the Women’s laser radial (dinghy) on Monday, she learned that she was pregnant.

The 27-year old athlete claims she didn’t have sex over the last three months, and believes her that her pregnancy was caused by the presence of sperm in the polluted water.

“I went to sail the first day I was here, and there were lots of condoms and syringes floating on the water. It was really disgusting!” she told reporters.“It really disturbed me to see all the trash, so I lost my concentration and fell in the water. I knew that the water could make me sick, but I never expected to become pregnant!”

The coastal waters around Rio de Janeiro has been contaminated with raw sewage and a large number of pathogens are lurking there and make people ill, experts say.

Spermatozoa can also survive up to twelve hours in water, which makes it possible to fall pregnant when swimming in water filled with “lots of condoms”, but the probabilities are “extremely low”.

The water around Rio is so polluted that tens of thousands of dead fish are collected every day by city workers.

The Associated Press reported levels of bacteria and viruses so high, that swallowing just three teaspoons of the foul-smelling murky water from the bay was likely to lead to severe stomach and respiratory illnesses.

In its latest advice, the World Health Organization said: “It is suggested that all athletes should cover cuts and grazes with waterproof plasters prior to exposure, try to avoid swallowing the water, shower as soon as possible after exposure and, as far as possible, minimise their time in the water and avoid going in the water after heavy rainfall if possible.”

Most athletes have been pre-emptively taking antibiotics, bleaching their oars and training in protective suits. Despite these measures, Alvilda Jensen will more than likely, be only the first of many athletes to suffer from the contaminated water.