The study, the first ever of its kind, found that concentrations of antibiotics in some waterways exceeded the safe levels by 300 times. In the worst cases - found in countries including Bangladesh, Ghana and Kenya - levels were hundreds of times higher than the levels deemed safe.
The drugs end up in the world's rivers through human and animal waste, as well as from drug-making facilities and wastewater treatment plants.
One sample from Bangladesh had metronidazole -used for treating skin infections - exceeded the safe limit by 300 times.
And as the contamination has reached risky levels, the resistance is more likely to develop and spread.
Professor Alistair Boxall, Theme Leader of the York Environmental Sustainability Institute, is quoted as saying describing the results as "quite eye-opening and worrying, demonstrating the widespread contamination of river systems around the world with antibiotic compounds".
The researchers looked at 14 commonly used antibiotics in rivers flowing through 72 countries. A total of 711 sites were tested and antibiotics were found at 65 percent of the sites.
McConnell says Republicans would confirm a Supreme Court justice in 2020
Since 1900, only eight judges have been considered during a presidential election year, the Wall Street Journal noted in 2016. Bush should not name a Supreme Court nominee until after the election that year, should a vacancy arise.
Robert Mueller's statement doesn't help Trump
House Democrats want Mueller to testify publicly, though no date or arrangements have been set, and it's not clear that he will. Mueller went on to say that he hoped his brief, 10-minute remarks would be the last he made about the investigation.
Take a look at who else is in LSU's NCAA Regional bracket
Sunday night revealed the 16 teams hosting a regional in the 2019 NCAA Tournament with Baton Rouge making the list. Vanderbilt, one of the top teams in the country, will host the regional and the Commodores will play Ohio State.
Safe levels can range from 20,000 to 32,000 nanograms per liter (ng/l), depending on the antibiotic, according to new guidelines established by the AMR Industry Alliance, a coalition of biotech, diagnostics and pharmaceutical companies set up to provide sustainable solutions to curb antimicrobial resistance.
The study is further aiming to explore how this antibiotic contamination affects the aspects of the environment such as wildlife like fish, invertebrates and algae.
Even if relatively low levels of the drugs are found in rivers, it could still increase the likelihood of the development and spread of antibiotic resistance, researchers said. "Our data show that antibiotic contamination of rivers could be an important contributor". We know very little about the scale of problem globally.
Many of them evolved from the natural environment.
To counter that, Boxall said, it will be necessary to invest in infrastructure for waste and wastewater treatment, tighten regulations and clean up already contaminated sites.
"Our study helps fill this knowledge gap with data from countries that had never been monitored before".
The finds are due to be unveiled during two presentations at the annual meeting of the Society of Environmental Toxicology and Chemistry (SETAC) in Helsinki on 27 and 28 May.