Australian scientist's UV purification sticker helps Cambodian villages produce clean water for free
ABC Illawarra/ By Justin Huntsdale
Posted 2h ago
It is just a small sticker, but it could have an enormous impact on the 2 billion people worldwide without access to clean drinking water.
Key points:
Martin Butson has helped invent a small sticker that indicates when water has been purified through UV exposure
The stickers can be placed on a reusable plastic bottle and change colour when the water is safe to drink
The stickers have been used in a pilot program in Cambodia that has already helped thousands of people

The SAFE sticker is a UV purification label that works by simply sticking it on a bottle of contaminated water, putting the container in the sun and waiting for the UV light to kill harmful bacteria, viruses and microorganisms. ***

Wollongong scientist and co-inventor Martin Butson told ABC Illawarra Mornings presenter Nick Rheinberger the sticker removed the guesswork from using UV rays to treat water.

He said the World Health Organisation recommended bottles be kept in direct sunlight for six hours to purify the water. But it wasn't always a reliable method.

"It depends on what time of year it is. Cloud cover and the level of UV can change," Dr Butson said.

"That's where problems have come in the past — people have done it, and sometimes it works, and sometimes it doesn't.

"You need to know how much UV has been delivered to your bottles."

Helping Cambodian communities

The Butson family from Wollongong are well-known scientists and inventors.

Macinley Butson was named 2018 NSW Young Australian of the Year and invented a scale maille breast protector for cancer patients.

The family created The Water Gift charity to provide SAFE stickers to Cambodia and, for the past one and a half years, have been completing pilot programs in rural areas of the South-East Asian country.

Dr Butson said the response had been "absolutely incredible".

"We've been over there a year and a half now, and we've worked with local villages in northern Cambodia in the Siam Reap province and surrounding lake areas, mountainous regions and urban slums on the outskirts of Siam Reap," he said.

"We provide education and teach them the process of collecting and cleaning bottles, putting the sticker on and looking at it."

Pech Tang from Thnaut Kambot Village said she had encouraged other people in her village to use the SAFE sticker.

"Before we would get stomach aches from the water but now we are much better," she said.

"It is easy to use, saves time and we are not sick now — we are telling other people how good it is."

He said the sticker was cost-effective and easily accessible to people in poorer countries as it relied upon the sun to do the work.
How it works
The sticker has a light pink patch in the middle, which gradually changes to black with UV exposure, meaning it is safe to drink.

For many Cambodians, water is sourced from a well, the lake or even in puddles on the side of the road.

Dr Butson said the one consistent element was the water was always contaminated with harmful bacteria that could cause diarrhoea, stomach cramps and other health issues.

"We started with 10 families, which is up to about 1,000 now, and we go back every few months and find families that want to join in," he said.

"There was a time we arrived in a village unannounced, and we could see all the bottles out with the stickers on, and a family had little bottles as well that the kids can take to school."
https://www.abc.net.au/news/2023-07-19/ ... /102609532

*** What is SODIS (solar disinfection)!

Solar disinfection (SODIS) is a process which is the cheapest form of water disinfection on the planet. It freely uses the sun and more importantly the UV rays from the sun, to disinfect the water by killing the harmful bacteria, viruses and microorganisms in the water.

There are already many millions of people around the world who use SODIS, but there was a problem. How long do you leave the water out in the sun before it is safe to drink? The World Health Organisation (WHO) recommendations are time based and they say that after 6 hours of exposure, the water should be safe to drink. But we know that the amount of UV in the sun's rays changes during the day. It changes whether there are clouds in the sky and how thick those clouds are. It changes depending on the altitude or place you live on earth and it changes depending on what season, eg: summer or winter time, it is. So it can be unclear whether the SODIS process has actually been achieved or not after 6 hours of sunlight exposure. This fact has significantly held back the use of SODIS around the world because people start to use it but then, when they use it and there hasn’t been enough UV to kill all the “bugs”, the people get sick again and then lose confidence in the process.

The SAFE Sticker Pilot Program: https://thewatergift.org/about