WHAT happens when you pop a couple of paracetamol for a headache?

Hopefully, after a while, you'll start feeling better. But what then?

Often, a large proportion of the medicine you've taken will be flushed out of your system next time you go to the loo. From there, it will make its way into the drains. And from there, inevitably, it'll end up in our rivers.

Not just paracetamol. Think of the myriad of pills people in York are taking every day: painkillers; anti-inflammatories such as ibuprofen; anti-depressants; antibiotics; and medicines such as metformin, prescribed for Type 2 diabetes. All end up making their way into the water.

Prof Alistair Boxall and his team from the University of York have been studying the levels of such drugs in the River Ouse and River Foss in York every month for two years. And when they compare the level of different drugs found in the river water with records of what was prescribed in the city that month, they see a clear correlation. The medicines ending up in York's rivers are the very ones being prescribed to York people.

Only in the summer season does that change - when tourists bring their own medicines that were prescribed elsewhere, and these also make their way into our rivers.

This probably all sounds quite scary. Water treatment plants are generally pretty good, but some of these drugs are not filtered out of the river water when it is processed for drinking - meaning that every day, we're drinking medication prescribed for other people.

York Press:

Prof Alistair Boxall

You don't need to be too worried, Prof Boxall stresses. There's a lot of water in the Foss and the Ouse, so the concentrations of these medicines in our river water is extremely low.

But they're there. And they could be having an effect on the wildlife which uses our rivers.

Research has shown that contraceptives that make their way into UK rivers are causing some male fish to develop female characteristics. Anti-depressants flushed into our rivers change the behaviour of other fish, so that males and females of the same species behave differently towards each other.

Researchers in York have shown that anti-depressants in the water have also been affecting the appetite of starlings, while some pharmaceuticals which make their way into our water have been affecting snails - making it harder for them to cling to rocks or stones.

There is also a worry that the flushing of antibiotics into our rivers could contribute to the increase in antibiotic-resistant bacteria which is now causing the medical profession so much concern.

The problem is that we don't really know exactly what's going on, says Prof Boxall. Apart from the very few cases we have studied closely, we just don't know what effect the myriad of drugs being flushed down our drains every day are having on our environment, our rivers or the wildlife which lives there.

He and his team at the University of York's Environment department want to change all that. They're working with the pharmaceutical industry to try to identify which of the 1500-or-so chemical compounds used in the medicines we take are most likely to cause problems when they get into the water system.

f they can do that, it will mean scientists and the pharmaceutical industry can focus more effectively on monitoring potentially harmful chemicals and tackling the problem.

York Press:

What effect are medicines in our rivers having on the environment? We need to find out, says Prof Boxall. Photo: Carolyn Clarke

Prof Boxall and his team are also working on a programme that, in the short term at least, could also potentially have a big impact.

The programme aims to encourage people with medicines they haven't used to return them to a pharmacist so they can be properly disposed of, rather than just throwing them away. Most people don't even know that pharmacies offer such a service, Prof Boxall says. But doing something as simple as returning drugs to the pharmacy could make a big difference.

That is one of the messages he will be hammering home when he gives a public talk about his work on Wednesday.

He is just one of several University of York scientists who will be speaking about their work at the latest York Talks day, which runs all day from 9am until 5.15pm on Wednesday in the Spring Lane building just off University Road on the university's original campus.

All the talks are free, and open to the public. And they're a great way of finding out about some of the amazing scientific research that is taking place right here on our doorstep.

Other York scientists will be talking on Wednesday about everything from trying to make car fuel from water to the use of facial recognition technology to catch criminals - and how controlled fires could help restore the savannah grasslands of Africa's Serengeti national park (see below).

There will be 16 talks in all, in four sessions throughout the day. While admission is free, booking is advisable - just visit www.york.ac.uk/research/events/yorktalks/


Other talks on Wednesday will include:


Fires are generally seen as destructive. But in the savannah grasslands of Africa, just the opposite may be true, says ecologist Dr Colin Beale, of the university's biology department.

Just over a million years ago, man's early ape-like ancestors, the hominids, discovered fire. They began lighting fires in the savannah, burning back the older, taller grasses to create areas where new, lush young grass could grow which would attract grazing animals. "They could then hide in the long grass, and hunt the animals which came."

Over the last million years man, the grasslands themselves and the wildlife which lives there have evolved together in a complex balance. Even when modern humans developed pastoral farming, the people of the savannah grasslands continued with the use of traditional burning methods which maintained the balance.

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Grasslands in the Serengeti. Photo: Colin Beale

Since the 1970s, however, things have been getting increasingly out of balance. A combination of climate change, population growth and the rejection by Nyerere's government in the 1970s of the tribal system and of traditional village-based land management measures have led to the loss of grazing lands to thorn scrub and land degredation.

The use of fire can actually be a very subtle and effective way of restoring the health of the savannah, Dr Beale says. The traditional skills once passed on by village elders have been lost. The problem is that there are many different types of fire, Dr Beale says - hotter and less hot, small or more extensive.

York Press:

Dr Colin Beale

He and his team have been trying to work out the best ways of burning to suit a range of different situations. And the aim is to give villagers in the Serengeti a 'toolkit' of methods that they can use to burn back thorn scrub and encourage growth of fresh new grass that will restore their grazing lands.

Such techniques would not only benefit the farmers themselves, but also the wildlife of the Serengeti, he says. "So if you get it right, everybody wins."


Water is a molecule made up of two elements - hydrogen and oxygen. It is perfectly possible to split these elements apart, turning water into oxygen and hydrogen. The hydrogen generated makes a perfectly good fuel - cars and even buses have been built which will run quite happily on hydrogen.

This is good news, because it means there is potentially an almost limitless supply of fuel. "There's lots of water all over the place!" points out Dr Alison Parkin of the university's department of chemistry.

The problem is generating hydrogen from water in large enough amounts to make it practical as a fuel for mass use. Traditionally, the process requires the use of platinum. This is essential to the chemical process of electrolysis which results in the oxygen and hydrogen atoms splitting. But platinum is a rare and precious metal - and we don't have enough of it to generate hydrogen fuel in industrial quantities.

York Press:

Dr Alison Parkin

So what if we could persuade bacteria to do the job of splitting water into oxygen and hydrogen for us?

Tiny single-celled organisms called cyanobacteria already do this, Dr Parkin says. The trouble is, they stop doing so once oxygen levels reach a certain level. And because the process generates oxygen as well as hydrogen, that means they stop far too quickly to produce quantities of hydrogen that would be useful to us.

Because of our huge leaps forward in the understanding of DNA, however, we should be able to tweak the DNA of the bacteria so that they go on splitting water into hydrogen and oxygen for much longer.

You could then have large cyanobacteria power plants floating offshore, generating hydrogen fuel that could be pumped ashore and used to fuel cars, buses and even power stations. And the only by-product, theoretically, would be oxygen - which we all need to breathe anyway.

So how far are we from being able to do this? It will depend on how much funding is made available for the research, says Dr Parkin. If the political will was there, the funding could be found.

"The choice is in our hands. We have the talent and the ingenuity and the ability to make these things happen. I know what I would prefer over fracking!"