Science Interviews


Mon, 17th Aug 2015

Talking about toilets

Dr Alison Parker, Cranfield University

Listen Now    Download as mp3 from the show The Yuck Factor: Why we find things disgusting

People’s attitudes to what they find disgusting can change over time, and this is Disgusting toiletsomething researchers are trying to harness to make the world a better place. Shockingly, there are billions of people around the world without access to adequate sanitation - in fact, more people have access to a mobile phone than to a proper toilet! Alison Parker is a Lecturer in International Water and Sanitation at Cranfield University, and she is working to tackle this problem.  She told Kat Arney why people tend to try to avoid poo wherever possible...

Alison - I think we have a natural disgust reaction to poo because it does smell pretty bad. We’re also taught that by our mothers when we’re little, about washing our hands when we’ve used the toilet and…

Kat - Don’t put your hands in the potty.

Alison - We’re taught to leave the toilet in a state that someone else might want to use it afterwards.

Kat - Ideally, yes. What about other parts of the world? We heard Alex talking about cultural differences in levels of disgust. Does that same attitude persist all over the world, particularly in places maybe where they don’t have such easy access to flush toilets and things like that?

Alison - I think it does. We’re all naturally disgusted by faeces, but what can change is people don’t understand how their faeces might end up in their drinking water. So, I had a student travel recently to India and she found that people there didn’t understand that even if water looks clean, it might not be safe to drink because it might have things in it that were too small to see, but would actually make them ill.

Kat - And also, I guess in many parts of the world where they don’t have access to kind of nice toilets or the kind of toilet you'd want to use, people are just doing their business anywhere I guess.

Alison - Yes. Open defecation can be quite a challenge. People go out maybe at night under the cover of darkness because they don’t have anywhere to go to the toilet. This is particularly risky for women who, going out at night, face risks from rape as well as things like snake bites as well.

Kat - And so, when it comes to trying to sort out these problems, tell me about some of the ways that you and your team are trying to address the problem of people not having access to decent toilets because we’re very lucky here in the west. We have lots of fresh water to flush our toilets with, lots of toilets, a toilet in every home. What are you working on?

Alison - So, we’re working on a number of different technologies that will help people have access to toilets when they don’t have running water, a sewer, maybe even access to power as well. So, one of the projects we’re working on is called a nanomembrane toilet. This is a toilet that will work in those situations – working completely off grid to give people somewhere safe to  go to the toilet.

Kat - So, how does it work? A nanomembrane toilet sounds very technologically sophisticated. Talk me through it.

Alison - So, the first stage of the nanomembrane toilet is the waterless flush. So, it’s a rotating bowl with a scraper that scrapes the waste into a holding chamber below.

Kat - So, instead of it just being flushed away, like it’s still vanishing from you, out of sight, out of mind kind of thing.

Alison - Yeah. It’s really important in our studies with the users that they can't see or smell waste after they’ve produced it. So, that’s a very important part of the system.

Kat - And then what happens to it? It’s gone into this holding chamber. What next?

Alison - The next stage is the membrane stage. So, in the holding chamber are membranes. Membranes are like sieves. They’ve got really small holes in them. In fact, these holes are so small that only water molecules can pass through. So actually, water is the smallest component of human waste.

Kat - So let me get this straight. You are sieving the water out of human wee and poo, and what quality is the water that comes out?

Alison - It’s actually very, very good. It would be good enough to drink.

Kat - Right. So I failed the kind of the nappy chocolate spread test. If you gave me a glass of water and said, “Okay, this has been filtered out of poo” I think I would struggle to drink that. How is this kind of technology going down with people?

Alison - So, in our initial studies in Ghana, we found that actually people were prepared to drink it, which surprised us as well. But actually, there are plenty of things that we need water for in the home that isn't drinking. So, for watering plants, for washing, lots of things that don’t involve us actually consuming it and those are needs as well. So, the water can be used for that.

Kat - What parts of the world could this kind of technology be used for?

Alison - Well, anywhere where there isn't a good sewage network which in many cities in Africa and Asia, it can be, 80 per cent of the city cannot have access to a sewer. And in rural areas, that percentage is even higher.

Kat - I mean, what about here say, in the west as well because I find it crazy. I think it’s something like 50 litres of fresh drinking water per person per day in the UK is just used to flush our waste away because we find it so disgusting. We’re prepared to use drinking water. Could this kind of technology, do you think, be adopted here in the UK too? I mean, water is a very important resource.

Alison - Certainly, we’ve had a lot of interest from people who have caravans, boats or just live in remote areas where they don’t have sewers so we’ve had a lot of interest from that. I think it’s an interesting example where something that’s a technology being developed for use in low income countries could actually end up being transferred back to higher income countries particularly as water stress increases.

Kat - For so long, we’ve had this taboo about poo. It is disgusting. No one wants to think about toilets. Maybe no one really wants to work on toilets. How exciting is it now that there suddenly seems to be interest in finding new toilet solutions?

Alison - I think it’s really exciting because the disease burden from poor sanitation is just huge. Yet, no politician wants to be stood next to a toilet, having their photo taken showing that this is what they’ve invested in. But actually, there is a growing interest in sanitation, a growing number of people working to develop new toilets thanks a lot to the Bill and Melinda Gates Foundation who funded a huge programme in this area.

Kat - So, we need toilets for the 21st century, not for the 5th century.

Alison - Absolutely.

Kat - And just finally, what is the most disgusting toilet that you’ve ever had to use on your travels?

Alison - So I think, probably some of the worst ones I've seen are the public toilets in Ghana. So, some people there believe that they will get ill from squatting over the normal squat hole where people are meant to squat. So, they do their business next to the toilet and then just leave it like that for the next user. So, if you are that next user, it’s pretty disgusting.


Subscribe Free

Related Content

Not working please enable javascript
Powered by UKfast
Genetics Society