What is the prescription for pharma pollution?

The environmental side effect of pharmaceuticals entering waterways is an under-debated but increasingly alarming issue. It has sparked calls for an overhaul of the way commonplace medicines are prescribed and for the environmental impacts of drugs to be considered alongside cost and effectiveness. Scottish Water's chief scientist talks through work to monitor and map pharmaceuticals in our waters.

Over the past 15 years, there has been a 40% increase in the number of prescriptions issued in Scotland, all of which ultimately reach the water environment. The build-up of these pharmaceuticals in the environment impacts animal and human health including development of antimicrobial resistance, which the World Health Organisation (WHO) declared to be one of the top 10 global public health threats facing humanity.

Failure to address this problem could result in 10 million global deaths annually by 2050 and cost an astonishing £66 trillion in loss of productivity, according to UK government modelling.

“Our use of these chemicals to support and improve our health is closely coupled to the health of animals and our shared environment,” says Elise Cartmell, chief scientist at Scottish Water. “We cannot keep utilising pharmaceuticals as our treatment of choice at the detriment of the environment.”

Although many substances are removed through wastewater treatment, certain medicines survive the process, Cartmell explains. Understanding where these are entering the system and when it is possible to offer alternative treatments is at the heart of a partnership supported by Scottish government.

Scottish Water formed the One Health Breakthrough Partnership (OHBP) to reduce environmental pollution from healthcare practices together with health bodies including NHS Highlands, regulator Scottish Environment Protection Agency (Sepa), academia and research groups.

It raises awareness of the impacts of pharmaceuticals on waterways, biodiversity and the wider environment and is mapping the presence of substances in the water to plan effective interventions.

Through water quality monitoring upstream and downstream of wastewater treatment sites, in bodies of surface water it has identified substances of concern ranging from well-known steroids oestrogen, antibiotics, betablockers and ibuprofen.

These enter waterways through human excretion, improper disposal, hospitals, use in agriculture and the industrial manufacturing of them.

“Some chemicals are effectively removed through existing processes but others go right through the wastewater treatment systems,” Cartmell explains. “These then have an impact on surface waters, the water environment and the wildlife dependent on that.”

Cartmell says the OHBP is striving to find interventions that support human health as well as environmental and animal health. This must also balance efficacy of treatment with cost.

Since receiving funding from the Medical Research Council, the OHBP has been developing a framework incorporating environmental impacts and data of medicines and their use into the prescribing process.

All the drugs that GPs and hospitals can prescribe and use are on a formulae list based on clinical effectiveness, as well as cost effectiveness, Cartmell points out. The OHBP wants that list to also take into account the environmental impact of pharmaceuticals.

A way of assessing the environmental impact of different substances is being developed. At present the group is using learnings from similar international projects together with rankings from toxicology risk assessment frameworks. OHBP then interprets how these apply to Scotland and the information is fed to the NHS.

Water quality testing to build a map of drug use

Data on water quality is gathered from hospitals, surface water, downstream from treatment works, lochs, rivers and upstream from treatment works as well as influent and effluent adjacent to treatment works.

Through this information, the group is creating a baseline of water quality information presented in an open data platform. “As we make interventions, we want to know where the problems are, where the hotspots are and are the interventions actually having any positive impact,” Cartmell says.

Work initially focused on urban areas with higher volumes of medication entering low-dilution water sources but has now expanded to rural locations as well.

Water quality data is then linked to pharmaceutical information – what has been prescribed where – and linked to wider monitoring data. This uses the same platform that Covid-19 wastewater monitoring data was presented through. Data is then overlaid with drainage and wastewater treatment catchment areas.

Cartmell explains the work has highlighted trends in usage – such as seasonal use of medicines to treat chest infections and a drop-off of substances when people had less access to GPs during lockdown.

Next steps

The data helps inform interventions to reduce pharmaceutical pollution and is the first time this has been done in Scotland. However, the OHBP recognises the drugs for human use are only part of the picture. It also wants to build an understanding of the impact of veterinary drugs on the water landscape.

Better awareness of non-medicinal treatments for pain relief or encouraging blue-green prescribing to improve health to reduce intervention are also in the remit of the group, together with campaigns about appropriate disposal of pharmaceuticals.