A study by scientists at the University of Leeds suggests that pharmaceutical pollution – small amounts of drugs like painkillers and antibiotics – is widespread in British rivers, and highlights the current lack of regulation around it.
Dr Paul Kay, lead author on the study, which was published in the journal Environmental Pollution, and his colleagues found that small amounts of five pharmaceutical drugs were present in the majority of samples taken from the rivers Aire and Calder in West Yorkshire over an 18-month period.
One of the drugs found was an antibiotic. Kay told BuzzFeed News that letting antibiotics get into rivers like this could contribute to the growing problem of antibiotic resistance, where antibiotics stop working as the microorganisms they attack become resistant to them.
“If we're discharging antibiotics into rivers all the time, and bacteria are being constantly exposed to them, then obviously they're going to develop resistance,” he said.
The five drugs the scientists looked for in this study were erythromycin, an antibiotic; propanolol, a beta blocker used to treat high blood pressure; and the painkillers diclofenac, mefanamic acid, and ibuprofen. Each drug showed up in between 51% and 94% of the samples taken.
“In this particular study we only looked at five drugs, but there are potentially hundreds if not thousands of drugs in rivers," said Kay.
The fact that drugs end up in waste water, and then in rivers, has been known for a while. “The surprising thing was the frequency with which they're there, which was more or less all of the time,” said Kay. “And the fact that, from our study, they just don't seem to dissipate in rivers as we would expect them to do, based on our understanding from lab experiments.”
Kay and his colleagues took samples as far as 5km downstream from wastewater treatment plants, where the drugs are likely to have entered the river, and found that the drugs did not seem to get broken down or diluted.
Dr Andrew Singer, a senior scientist at the NERC Centre for Hydrology and Ecology in Oxfordshire, who was not involved in the study, told BuzzFeed News the findings are consistent with other research that show “considerable concentrations of pharmaceuticals in waste water, including antibiotics".
“It is clear that antibiotics are widespread in our environment, with a large amount of it coming from sewage effluent,” Singer said. “The implications for human health are inferred from what we see happen in isolated cases, particularly on farms where farmers of animals receiving antibiotics are often found to have much higher prevalence of antibiotic resistance in their gut microbiota than would be typical of most humans.
“By having widespread antibiotics in the environment we risk increasing the prevalence of antibiotic resistance genes in the microbes found in the environment. These ‘environmental microorganisms’ can find their way into humans through water, air, animals, and food. Once they enter humans they can rather easily transfer these resistance genes to a pathogen."
The effect of such drugs on wildlife is not yet clear. Professor Andrew Johnson, an environmental research scientist at NERC, who was not an author on the paper, told BuzzFeed News: “Essentially I don’t think science is set up in this field to answer these questions, but what we can see so far is not all that alarming.”
“I don't think there are any enormous disasters happening," Kay said. “On the whole it’s chronic impacts we’re looking at.”
The amount of drugs that can be present in rivers is not yet regulated.
Pharmaceutical pollution has only really become an area of research in the last two decades, thanks to improved methods of detection. “Before then it just technically wasn't possible,” said Kay. Now that it is, he expects regulations to come eventually, but says we could be waiting up to 10 years for it to happen.
In the last few years, several pharmaceutical drugs have been added to a European “watch list” of substances that, pending more evidence, may eventually be added to a “priority substance list” of pollutants that should be limited.
When you take, say, ibuprofen for a headache, not all of the drug is broken down by your body. The bit that you don’t break down ends up in your urine, which then goes down the sewer and into sewage treatment works.
“Often between about 30 and 90% of what you take doesn't get metabolized by your body,” says Kay. “Sewage treatment works aren't actually designed to take drugs out because there's no regulation for the water industry to focus on, which is logical given that we haven't actually been able to measure these things in the environment for very long.”
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