Episode 9

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Published on:

9th Jan 2023

World Changers: Chemical pollution knows no borders

Chemical pollution knows no borders: Global problems need global solutions

Dr Laura Carter’s research has found hazardous traces of chemicals in plants, soil and water from Yorkshire to remote rivers in Nepal. Now she’s creating an international network of academics, industry and regulators to pool knowledge and draw up frameworks so we can better manage such pollution crises across the world.

Transcript
Simone:

Research that changes lives.

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Four simple words, inspiring researchers at the University

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of Leeds to reshape the world.

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I am Professor Simone Buitendijk, since arriving at the University

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in 2020 as Vice-Chancellor.

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I've been amazed by the passion, creativity and ingenuity of the

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research community to make a difference.

Lucy:

Having the opportunity to exercise choice is really key to palliative care

Lucy:

and that individualised care that supports the person in the last few months of life.

Cristina:

We need to learn from the mistakes that we've made and we

Cristina:

need to learn from the instances where prevention atrocities work.

Leah:

I think the COVID-19 pandemic actually forced us to become a

Leah:

little bit more digitally literate.

Leah:

Although I do think we still have some room to kind of, continue growing.

Simone:

One of my priorities has been to learn more about the sheer

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range of research carried out by early career researchers at Leeds.

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They are the new generation of world changers people working tirelessly

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with communities and academics around the world on finding solutions to

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seemingly intractable problems.

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Over the course of this podcast series, I will be in conversation

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with those researchers.

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Join me as our World Changers described new discoveries and

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approaches that will make the world a better and more equitable place

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to live.

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It's about research that changes lives.

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Thank you for listening to this World Changers podcast.

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I'm Professor Simone Buitendijk, the Vice Chancellor.

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In this edition, we will be looking at the environmental impact of medicines.

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Pharmaceutical drugs have revolutionised health care,

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but they come with an ecological cost by products from pharmaceutical,

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manufacturing and pharmaceutical use contaminating the environment.

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What risk does this contamination pose for human

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health, wildlife and importantly,

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the development of superbugs which are resistant to antibiotics?

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To explore this issue, I am joined by Dr.

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Laura Carter, Associate Professor in Soil

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and Environment Chemistry in the School of Geography at Leeds.

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She's mapping the way chemicals from medicines are flowing

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through the environment and is helping to identify ways they can be controlled.

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Laura, thank you for joining us.

Laura:

Thank you.

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So we'll get into the detail of your research very shortly.

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But but in headline terms, could you tell me

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what your research is doing and how it's revealing this double edged

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sword of medicines?

Laura:

Yes, absolutely.

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So medication is is really a crucial element

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of almost every type of care that we receive.

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And pharmaceuticals are one of the most common forms of health care intervention.

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And I'm not suggesting that because of these

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identified environmental costs,

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that we need to stop using medication.

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What we really need to do is fully understand the risks

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that are associated with that inadvertent release into the environment.

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And with this understanding, we can tackle the issues

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through improved regulation or the development of less hazardous

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alternatives, for example, or even through

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the introduction of measures to to minimise any risk.

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And research is

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is really crucial to identify what the issues are and then to ensure

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that we're targeting our solutions to to where we need the most.

Simone:

Yeah, it's actually it's such important work you're doing.

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And it's interesting.

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I think your your interest in this area was, was sparked was awakened

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when you were an undergraduate students and you became aware of the invisible

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pollutants, as you call them, I think, from pharmaceutical production and use.

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And can you tell me what it was exactly that you were discovering?

Laura:

Yes. So I was part of a summer internship at a water company

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and I became interested

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in water quality and pollution

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because we were able to detect chemicals in the environment

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and we were seeing effects in organisms that we couldn't see the contamination.

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So you couldn't see pills floating around in the rivers.

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So as part of my undergraduate project.

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I then was able to take this this further and looked at the accumulation

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of drugs into aquatic invertebrate.

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So I looked at the accumulation into water snails.

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And this is really where

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I guess my interest in this started.

Simone:

Wow thats really fascinating.

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So so your research at the moment, I think, focuses almost

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especially on understanding the pathways that are putting these contaminants

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into the environment.

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And you've described pollution from medicines as ubiquitous.

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And what exactly do you mean by that?

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I mean, I know what the word means, but you must have a research

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explanation for the word ubiquitous.

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What does it mean for you?

Laura:

Well, most pharmaceuticals and not very persistent,

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but the problem is that you have this continual

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addition to the environment in small but significant amounts

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and this continual influx, despite there degradation and removal

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by the various processes, causes this pseudo persistence.

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And this is the result and is the development

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of this complex pharmaceutical pool in many natural environments.

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And in the past three decades, I believe pharmaceutical residues

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have been discovered in almost all environmental matrices in every continent.

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So this is including things like surface water, the groundwater, soils

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and sediments, and this is why we refer to them as ubiquitous contaminants.

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Yeah, and I know one of your examples, actually,

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I had no idea that there was an issue that was so widespread.

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Indeed,

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that is about the effects on wildlife, and that was, for me, completely new.

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And you use an example of the vulture population in parts of Southeast Asia.

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Can you talk a little bit more about that?

Laura:

I think what's really important to point out here

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is the fact that drugs or medicinal chemicals

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are designed to be biologically active

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and to elicit a therapeutic effect.

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And this potency is not lost when these chemicals enter the environment

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so they can interact with receptors in the organism, such as fish or plants,

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and then they can initiate this toxic response.

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And in the case of the vultures

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and diclofenac, this is just one example of a toxic response.

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So diclofenac is an anti-inflammatory medicine,

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and it's routinely prescribed and available over the counter as well.

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But it's also prescribed to animals as a veterinary drug, including cattle.

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And it's now transpired that this medicine was toxic

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to vultures, even in small doses, because it resulted in kidney failure.

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So in India, in Pakistan and Bangladesh,

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they saw a sharp decline in vulture populations.

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In some cases it was over 99% and it was found

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that the vultures were being contaminated after they

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ate the the carcasses of cattle that were given the drug.

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And so it's been suggested that millions of vultures

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have died as a result of this exposure.

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And, do you know, if these populations are back now

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in numbers since that has been discovered?

Laura:

No they're not they haven't fully recovered.

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And we've also found the presence of diclofenac residues

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in vultures in European vultures now as well.

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So it's not a problem that's just consolidated to Southeast Asia.

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It’s a really important work.

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So, Laura, let's talk a little bit about your research in India.

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Can you tell me exactly what you're doing there?

Laura:

So the majority of the world's antibiotics are produced

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in pharmaceutical factories in India and the waste released

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from these manufacturing plants ultimately ends up in the environment.

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And this is mainly through

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the discharge of effluents into rivers.

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And this river water can then be used to irrigate

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agricultural landscapes.

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And this often happens

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after the waste has received little or no treatment.

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And this creates an enormous potential issue

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as the more we expose bacteria to antibiotics,

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the faster they evolve the resistance to the drugs,

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which means that we're unable to use them to treat infections.

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So we're interested in

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quantifying the presence

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of these contaminants in the receiving environment.

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So in the waters and in the soil is where the irrigation water

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is used to determine what is present and at what concentrations.

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And then we're collaborating with microbiologists at the University

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of Birmingham, who we're going to explore the impacts

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on the microbial communities.

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Yeah, and that's that is a major issue.

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So you're specifically looking at that in your research

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that the way these microbes, microbial

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communities populations are changing?

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communities populations are changing?

Laura:

Yes, this is a joint project combining

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environmental chemistry and microbiology expertise and across the UK and India.

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And our project is is built on

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the idea that this release of this waste, this antimicrobial production,

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waste results in a whole suite of chemical compounds

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being released into the environment,

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which have the potential to have significant effects

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in microbial ecosystems.

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And this creates this selection pressure for the evolution

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of antimicrobial resistance.

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I able to tell us anything about the early results of this project?

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We've had some quite

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significant delays due to Covid,

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but we've actually started the monitoring campaign

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in India at the moment

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and we're sampling environments into which

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antibiotic production waste is released

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and then we're comparing this to pristine environments

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and this will allow us to determine exactly

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what effects the waste has on the microbial ecosystem.

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So specifically, does it kill all the beneficial bacteria

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to only leave the harmful resistant bacteria alive?

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So our first samples from India have arrived in Leeds

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and we're working to determine how much of the active antibiotic

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is present in lead in samples,

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is present in samples,

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but also what are the potentially toxic chemicals are contained within the waste,

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so it's too early

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to have any specific results hopefully in the next couple of weeks.

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Yeah, I have to talk again at some point

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and I'm curious why as to

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why the contaminants are being released and from these manufacturing plants

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is that lack of regulation and or no enforcement

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or thought, why does this happen?

Laura:

This is a difficult question and it's scenario specific,

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but I think it's the combination of both

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the lack of regulation and regulatory enforcement.

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So where regulation is in place, it's often

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disjointed between regions within a country

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and not properly financed and supported to ensure long term compliance

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and where you have treatment options available.

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These are also not funded.

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So maintenance and operational efficiency of the treatment systems are quite poor,

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which then means that you have this release into the environment.

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Yeah.

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And if I understood from your essay

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that it's not just the waste from plants that's contaminating the environment,

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it's also that when humans use a medicine or I guess,

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when it's used for cattle or whatever

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the bodies excrete residues and that those can

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then pass into sewage systems and the environment.

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And can you talk a little bit about that?

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The pathways into the environment.

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The pathways into the environment.

Laura:

So with human use, pharmaceuticals, their consumption

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and subsequent excretion into sewage presents

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this pathway by which they can into the environment

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following the the use of wastewater treatment byproducts.

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So by this I'm talking about effluent and sewage sludges. So effluents

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and sewage sludges can be applied to agricultural fields

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as a source of irrigation, but also as an agricultural fertilizer

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and use of slurries and manure on land.

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As an agricultural fertiliser also provides a route by which

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veterinary medicines can also enter our soils

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and these drugs

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can move from the soil into crops.

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And this is something that we have demonstrated here at the Leeds and research

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elsewhere as well is looking at the impact on

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wildlife in rivers and on fish.

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So the drugs are ubiquitous in the environment

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and can really have an effect on a whole suite of species

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Apparently there's no way

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for these sewage treatment plants to remove the

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medicinal waste is there?

Laura:

So the sewage plants were not specifically designed

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for the removal of pharmaceuticals, and they do not completely remove

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all pharmaceutical residues.

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So remediation efficiencies

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can be less than about 10%

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in the cases of pharmaceuticals, such as aspirin

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or the anti-inflammatory that I talked about in relation to the vultures diclofenac.

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So wastewater

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treatment plants and unable to fully degrade the medicines

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because they're generally designed to handle other contaminants.

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That being said, some treatment options do result in a reduction

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in the concentration of these chemicals, say, for example, some antibiotics.

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But in general, the removal is very dependent

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on the medicine in question and the type of treatment process.

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Wow and do we know what the impact of this issue

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in some human health?

Laura:

So in terms of human health, this is only something which we've done

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theoretically with some calculations to consider human exposure.

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But studies elsewhere have shown that in some countries

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following the consumption of produce which has been irrigated using reclaimed

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wastewater drug residues, getting into humans

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as they've detected the active pharmaceuticals in the urine.

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So that's an example would be the Anti-epileptic drug

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and carbamazepine in this case.

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So how can we try and control all these problems? Because this sounds

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so big and overwhelming.

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In terms of solutions,

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I think promising options include

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really the better management and storage of waste.

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So for example, animal manures and fecal waste, a really

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great resource is their nutrient rich and they offer promising alternatives

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to chemical based fertilisers to support nutrient demands.

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And reusing these resources

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aligns also to concepts of the circular economy.

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So if we manage these resources properly, such as through

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composting or enhanced treatment

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and their application to land happens at the right time,

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then this can result in a minimal environmental contamination

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and provides a means of disposing of this waste.

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We also have work underway in my group at the moment,

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looking at the role of plants in the cleanup of medicinal

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residues, so from a proprietary remediation perspective.

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And I think the cost effectiveness of this approach is really important

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to considering countries, for example, where you may not have sewerage

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infrastructure or advanced treatment options in the first place.

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I think

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it's also important to consider

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the ability to implement behavioural change,

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to improve and to manage the disposal of unused medicines.

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Because if you're able to do this, then you're effectively

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eliminating or reducing the potential

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for these drugs to enter the environment in the first place.

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But I think what's really key to

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all of this is the need for a transdisciplinary approach to

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to make sure that we're coming at the most promising solutions.

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So our expertise in my group

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is around environmental chemistry that we need to work across disciplines

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to develop these effective mitigation measures.

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Yeah, it's a great example of how important it is to bring all disciplines

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together isn’t it.

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Yes this still is quite a large task.

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And these are one that's the University of Leeds World changers.

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And do you have any idea and how confident are you

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that we can identify the solutions and how long do you think it can take?

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Where would you start?

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I think, as I said from the beginning, what we need to identify

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solutions is to first understand the risk.

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So there's been a wealth of research published on this topic since I started in

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in this field, that the environment is inherently complex.

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It's a dynamic system.

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And then to add on top of this complexity

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and medicinal ingredients comprised of thousands of chemicals

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that have the potential to enter our environment.

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So it would be a much too far

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greater task to develop solutions.

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for every exposure scenario possible.

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So we need to think creatively and focus our efforts on the greatest risks.

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So thinking about which of the medicines are most persistent

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and which are the ones which are most toxic.

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And this is really core to my UKRI future leaders partnership.

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So the plan's research is designed to fill these knowledge gaps

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and we have prioritisation exercises underway

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which are helping to really understand where the greatest risk is.

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So I guess coming back to your original question, I'm confident

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that we're undertaking the research

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needed at the moment to make the solutions to this problem possible.

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Great.

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Pretty happy to saying that.

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And there's there's another reason I think we need to be concerned,

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because there is a possibility also of increasing microbial resistance,

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which is also a huge problem I’ve heard from

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one of the other World Changers, is that right?

Laura:

Yes. So the development of resistance is a natural phenomenon.

Laura:

And however we know that exposure to antibiotics can accelerate this process.

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So the extensive use and misuse of antimicrobials in humans and animals

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is increasing the development of antimicrobial resistance

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and this is really escalated it into a global health

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problem.

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But what is less clear cut is the role

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that antibiotic contamination in the environment plays in this process.

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Although under the one health approach to antimicrobial resistance,

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the connectivity between the environment and humans is acknowledged.

Simone:

That's great.

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Well, thank you, Laura.

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This has been an incredibly

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important conversation from my perspective.

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You've really shared a lot of insights. I’m really proud

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you're at the University of Leeds and you’re one of our World Changers

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I think it's a very worthy title for what you're doing

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and I hope you’re going be with us for a long time

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to come and keep supports in this research, I do think

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it can actually change the world if you keep doing what you’re doing, so thanks a lot for this

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this conversation and I’ll be really curious to find out what your research

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has brought up so please get in touch when we have more results.

Laura:

Thank you. It's been great to have the opportunity to talk to you.

Simone:

Thanks Laura

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Thank you for listening to this podcast from the University of Leeds, to find out

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more about the work of our early career researchers and to read essays written by

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World Changer researchers, please go to the World Changers page on the University

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website, details can be found in the information that accompanies this podcast.

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About the Podcast

Changing The World
A University of Leeds series featuring Vice-Chancellor Professor Simone Buitendijk
In this new monthly series from the University of Leeds, Vice-Chancellor Simone Buitendijk is joined by guests from across the organisation, and shares perspectives and insights on how we can change the world – through our behaviour, leadership, research and teaching.