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.

Research that changes lives.

Four simple words, inspiring researchers at the University

of Leeds to reshape the world.

I am Professor Simone Buitendijk, since arriving at the University

in 2020 as Vice-Chancellor.

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

research community to make a difference.

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

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

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

need to learn from the instances where prevention atrocities work.

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

little bit more digitally literate.

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

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

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

They are the new generation of world changers people working tirelessly

with communities and academics around the world on finding solutions to

seemingly intractable problems.

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

with those researchers.

Join me as our World Changers described new discoveries and

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

to live.

It's about research that changes lives.

Thank you for listening to this World Changers podcast.

I'm Professor Simone Buitendijk, the Vice Chancellor.

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

Pharmaceutical drugs have revolutionised health care,

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

manufacturing and pharmaceutical use contaminating the environment.

What risk does this contamination pose for human

health, wildlife and importantly,

the development of superbugs which are resistant to antibiotics?

To explore this issue, I am joined by Dr.

Laura Carter, Associate Professor in Soil

and Environment Chemistry in the School of Geography at Leeds.

She's mapping the way chemicals from medicines are flowing

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

Laura, thank you for joining us.

Thank you.

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

But but in headline terms, could you tell me

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

sword of medicines?

Yes, absolutely.

So medication is is really a crucial element

of almost every type of care that we receive.

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

And I'm not suggesting that because of these

identified environmental costs,

that we need to stop using medication.

What we really need to do is fully understand the risks

that are associated with that inadvertent release into the environment.

And with this understanding, we can tackle the issues

through improved regulation or the development of less hazardous

alternatives, for example, or even through

the introduction of measures to to minimise any risk.

And research is

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

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

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

And it's interesting.

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

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

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

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

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

and I became interested

in water quality and pollution

because we were able to detect chemicals in the environment

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

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

So as part of my undergraduate project.

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

of drugs into aquatic invertebrate.

So I looked at the accumulation into water snails.

And this is really where

I guess my interest in this started.

Wow thats really fascinating.

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

especially on understanding the pathways that are putting these contaminants

into the environment.

And you've described pollution from medicines as ubiquitous.

And what exactly do you mean by that?

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

explanation for the word ubiquitous.

What does it mean for you?

Well, most pharmaceuticals and not very persistent,

but the problem is that you have this continual

addition to the environment in small but significant amounts

and this continual influx, despite there degradation and removal

by the various processes, causes this pseudo persistence.

And this is the result and is the development

of this complex pharmaceutical pool in many natural environments.

And in the past three decades, I believe pharmaceutical residues

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

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

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

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

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

Indeed,

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

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

Can you talk a little bit more about that?

I think what's really important to point out here

is the fact that drugs or medicinal chemicals

are designed to be biologically active

and to elicit a therapeutic effect.

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

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

and then they can initiate this toxic response.

And in the case of the vultures

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

So diclofenac is an anti-inflammatory medicine,

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

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

And it's now transpired that this medicine was toxic

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

So in India, in Pakistan and Bangladesh,

they saw a sharp decline in vulture populations.

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

that the vultures were being contaminated after they

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

And so it's been suggested that millions of vultures

have died as a result of this exposure.

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

in numbers since that has been discovered?

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

And we've also found the presence of diclofenac residues

in vultures in European vultures now as well.

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

It’s a really important work.

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

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

So the majority of the world's antibiotics are produced

in pharmaceutical factories in India and the waste released

from these manufacturing plants ultimately ends up in the environment.

And this is mainly through

the discharge of effluents into rivers.

And this river water can then be used to irrigate

agricultural landscapes.

And this often happens

after the waste has received little or no treatment.

And this creates an enormous potential issue

as the more we expose bacteria to antibiotics,

the faster they evolve the resistance to the drugs,

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

So we're interested in

quantifying the presence

of these contaminants in the receiving environment.

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

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

And then we're collaborating with microbiologists at the University

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

on the microbial communities.

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

So you're specifically looking at that in your research

that the way these microbes, microbial

communities populations are changing?

communities populations are changing?

Yes, this is a joint project combining

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

And our project is is built on

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

waste results in a whole suite of chemical compounds

being released into the environment,

which have the potential to have significant effects

in microbial ecosystems.

And this creates this selection pressure for the evolution

of antimicrobial resistance.

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

We've had some quite

significant delays due to Covid,

but we've actually started the monitoring campaign

in India at the moment

and we're sampling environments into which

antibiotic production waste is released

and then we're comparing this to pristine environments

and this will allow us to determine exactly

what effects the waste has on the microbial ecosystem.

So specifically, does it kill all the beneficial bacteria

to only leave the harmful resistant bacteria alive?

So our first samples from India have arrived in Leeds

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

is present in lead in samples,

is present in samples,

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

so it's too early

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

Yeah, I have to talk again at some point

and I'm curious why as to

why the contaminants are being released and from these manufacturing plants

is that lack of regulation and or no enforcement

or thought, why does this happen?

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

but I think it's the combination of both

the lack of regulation and regulatory enforcement.

So where regulation is in place, it's often

disjointed between regions within a country

and not properly financed and supported to ensure long term compliance

and where you have treatment options available.

These are also not funded.

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

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

Yeah.

And if I understood from your essay

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

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

when it's used for cattle or whatever

the bodies excrete residues and that those can

then pass into sewage systems and the environment.

And can you talk a little bit about that?

The pathways into the environment.

The pathways into the environment.

So with human use, pharmaceuticals, their consumption

and subsequent excretion into sewage presents

this pathway by which they can into the environment

following the the use of wastewater treatment byproducts.

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

and sewage sludges can be applied to agricultural fields

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

and use of slurries and manure on land.

As an agricultural fertiliser also provides a route by which

veterinary medicines can also enter our soils

and these drugs

can move from the soil into crops.

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

elsewhere as well is looking at the impact on

wildlife in rivers and on fish.

So the drugs are ubiquitous in the environment

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

Apparently there's no way

for these sewage treatment plants to remove the

medicinal waste is there?

So the sewage plants were not specifically designed

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

all pharmaceutical residues.

So remediation efficiencies

can be less than about 10%

in the cases of pharmaceuticals, such as aspirin

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

So wastewater

treatment plants and unable to fully degrade the medicines

because they're generally designed to handle other contaminants.

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

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

But in general, the removal is very dependent

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

Wow and do we know what the impact of this issue

in some human health?

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

theoretically with some calculations to consider human exposure.

But studies elsewhere have shown that in some countries

following the consumption of produce which has been irrigated using reclaimed

wastewater drug residues, getting into humans

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

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

and carbamazepine in this case.

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

so big and overwhelming.

In terms of solutions,

I think promising options include

really the better management and storage of waste.

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

great resource is their nutrient rich and they offer promising alternatives

to chemical based fertilisers to support nutrient demands.

And reusing these resources

aligns also to concepts of the circular economy.

So if we manage these resources properly, such as through

composting or enhanced treatment

and their application to land happens at the right time,

then this can result in a minimal environmental contamination

and provides a means of disposing of this waste.

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

looking at the role of plants in the cleanup of medicinal

residues, so from a proprietary remediation perspective.

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

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

infrastructure or advanced treatment options in the first place.

I think

it's also important to consider

the ability to implement behavioural change,

to improve and to manage the disposal of unused medicines.

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

eliminating or reducing the potential

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

But I think what's really key to

all of this is the need for a transdisciplinary approach to

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

So our expertise in my group

is around environmental chemistry that we need to work across disciplines

to develop these effective mitigation measures.

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

together isn’t it.

Yes this still is quite a large task.

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

And do you have any idea and how confident are you

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

Where would you start?

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

solutions is to first understand the risk.

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

in this field, that the environment is inherently complex.

It's a dynamic system.

And then to add on top of this complexity

and medicinal ingredients comprised of thousands of chemicals

that have the potential to enter our environment.

So it would be a much too far

greater task to develop solutions.

for every exposure scenario possible.

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

So thinking about which of the medicines are most persistent

and which are the ones which are most toxic.

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

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

and we have prioritisation exercises underway

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

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

that we're undertaking the research

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

Great.

Pretty happy to saying that.

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

because there is a possibility also of increasing microbial resistance,

which is also a huge problem I’ve heard from

one of the other World Changers, is that right?

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

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

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

is increasing the development of antimicrobial resistance

and this is really escalated it into a global health

problem.

But what is less clear cut is the role

that antibiotic contamination in the environment plays in this process.

Although under the one health approach to antimicrobial resistance,

the connectivity between the environment and humans is acknowledged.

That's great.

Well, thank you, Laura.

This has been an incredibly

important conversation from my perspective.

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

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

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

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

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

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

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

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

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

Thanks Laura

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

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

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

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