Our directory of things of interest

University Directory

Pharmaceuticals in water supplies can lead to dangerous ‘happy fish’ phenomenon

Pharmaceuticals in water supplies can lead to dangerous ‘happy fish’ phenomenon
26 Feb
2020
The release of pharmaceuticals into rivers and lakes is having dramatic consequences for both human health and that of ecosystems

When people get ill, we mostly take medicines, get better, and by and large that’s the end of the story. For scientists studying our waste water however, it’s only the beginning. What’s often overlooked is that humans will then excrete pharmaceuticals such as antibiotics and antidepressants, with much of this waste ending up in the wild. Water treatment plants can filter out some of these drugs, but studies have demonstrated that persistent pharmaceutical residues are still sneaking through the metaphorical net.

Stay connected with the Geographical newsletter!
signup buttonIn these turbulent times, we’re committed to telling expansive stories from across the globe, highlighting the everyday lives of normal but extraordinary people. Stay informed and engaged with Geographical.

Get Geographical’s latest news delivered straight to your inbox every Friday!

What happens when these drugs enter our waterways? Diana Aga, a professor in the chemistry department at the University at Buffalo has been trying to answer this question. She explains that the results can be both varied and alarming. ‘Antibiotics are most interesting because at very low levels they encourage the development of antimicrobial resistance,’ she says. ‘Some major drugs are no longer effective in killing pathogens and that’s because pathogens have developed resistance.’ When it comes to human health this is certainly the most dangerous consequence. However, as Aga explains, there are also many other surprising consequences when it comes to fish and wildlife.

‘Two years ago, we showed that antidepressants that are excreted by humans end up in rivers and lakes, with fish then accumulating them in the brain,’ says Aga. ‘You have this effect – we call it “happy fish” because they’re under the influence of antidepressants. We haven’t yet shown it in the wild, but in lab experiments the fish don’t avoid predators anymore. The long-term effect might be a collapse in biodiversity.’

Other drugs can also have dramatic effects on ecosystems. Release of birth control pills into the wild has long been linked to endocrine disruption in fish. This can lead to males producing eggs or females no longer producing eggs. Some fish have even been shown to develop both female and male sex organs.

Aga and her team have been analysing how wastewater treatment plants could be adapted to avoid this problem. The most common method at such plants is called ‘activated sludge’, which involves microorganisms breaking down organic contaminants. But this is only partly effective when it comes to pharmaceuticals. Aga has demonstrated that adding two more processes known as ‘granular activated carbon’ and ‘ozonation’ can reduce the concentration of escaped residues by more than 95 per cent. These processes increase the cost of treatment considerably, but Aga emphasises that it’s a good investment. In particular, as populations grow and more and more cities worldwide consider recycling wastewater into drinking water, it could prove essential in preventing the drugs we take to cure us causing more harm than good.

SUBSCRIBE TO OUR MONTHLY PRINT MAGAZINE!
Subscribe to Geographical today for just £38 a year. Our monthly print magazine is packed full of cutting-edge stories and stunning photography, perfect for anyone fascinated by the world, its landscapes, people and cultures. From climate change and the environment, to scientific developments and global health, we cover a huge range of topics that span the globe. Plus, every issue includes book recommendations, infographics, maps and more!

Related items

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Geophoto

Kacper Kowalski's aerial photos capture the graphic shapes of our…

Wildlife

Invasive species are considered one of the greatest threats to…

Nature

Professor Steve Fletcher, director of the Global Plastics Policy Centre…

Wildlife

The international conservation agreement CITES is nearly half a century old.…

Wildlife

With Scotland’s salmon under threat, environmental groups are planting trees…

Oceans

As coastal development continues to grow, research begins to reveal the…

Wildlife

Research into rhesus macaques on a remote island finds that survivors of…

Climate

 The release of the latest IPCC report suggests it's 'now…

Wildlife

A new technique to collect animal DNA from thin air could…

Wildlife

As animal species decline, plants that rely on them to…

Nature

Calls to make ecocide a crime are gaining ground

Wildlife

In South Africa, a new wave of poaching has taken…

Tectonics

A volcanologist unpicks the devastating eruption of Hunga Tonga-Hunga Ha’apai

Oceans

Some areas of the ocean are richer in microplastics than…

Oceans

The ocean floor is home to rich deposits of metals…

Climate

The industry will only keep growing. Could algae help to…

Nature

A monumental effort is underway to map the world’s fungal…

Geophoto

In his project Black Dots, Nicholas JR White set out upon the…

Wildlife

China’s Amur tiger population is recovering, reflecting the country’s changing…

Climate

Scientists are pushing back against the notion that the food…