A Scottish project is aiming to reduce the impact of pollution from waste medicines on the environment.
An initiative involving NHS Highland is examining how to minimise the amount of pharmaceuticals entering rivers, lochs and the sea, which could pose threats to marine life.
The work has resulted in Caithness General Hospital in Wick becoming the first hospital in the world to gain an international standard in recognition of the efforts put towards greener water management.
Around £300m of medicines go unused every year in the UK, which are often disposed of by flushing down the toilet.
It is thought that between 30 and 90% of all medicines taken orally can end up in the waste water system after being excreted in urine.
The project in Caithness has involved carrying out analysis of changes in the quality of water from the source, Loch Calder, to Caithness General Hospital and onto the local wastewater treatment plant.
It is hoped the research findings can be applied to hospitals and other healthcare sites across the Highlands.
NHS Highland’s environmental and sustainability manager John Burnside said: “This project has enabled Caithness General Hospital to lead the way in reducing the impact the medicines we prescribe can have on the environment.
“We have a strong economic and social responsibility to the communities we serve and it is vitally important we reduce our carbon footprint.
“We are delighted that Caithness General Hospital is the first hospital in the world, and the only site of any kind in the UK, to be recognised with the Alliance of Water Stewardship standard.”
A collaboration of agencies has been involved in the initiative, known as the Green Breakthrough Partnership, including the Scottish Environment Protection Agency, Scottish Water, Highland and Islands Enterprise and the University of the Highlands and Islands’ Environmental Research Institute in Thurso.
Adrian Sym, chief executive officer of Alliance for Water Stewardship, said: “NHS Highland is at the forefront of a growing movement to tackle the impacts of pharmaceuticals on the environment and on public health, and has demonstrated global leadership by employing water stewardship as part of these efforts.”