Household and lifestyle activities are key contributors to water quality, according to new research from the University of Bath. Social interventions – such as social prescribing – may provide a more sustainable solution to this problem than improvements to wastewater treatment processes.

Using new tools developed by researchers at the University of Bath to evaluate the impact of a population on water pollution, scientists found a direct link between the size of a city and the quantity of harmful chemicals and biological agents released naturally into the environment after passing through people’s bodies or directly discharged via various activities, such as showering and dish washing.

It is hoped that the study’s findings will give local governments the impetus to establish policies that will better support the health and resilience of their city environments.

“Each of us needs to start considering our lifestyle as a factor contributing to deterioration of environmental health,” said lead researcher Professor Barbara Kasprzyk-Hordern from the Department of Chemistry at Bath. “First we need to acknowledge that we are responsible, through the way we live, for water contamination, and then we need to start finding solutions.”

Ruth Barden, director of environmental solutions at Wessex Water, which collaborated on the research, added: “It’s often more sustainable to remove the problem at source, for instance via social interventions, than to invest in end-of-pipe, energy intensive wastewater treatment processes that do not necessarily help reduce society’s carbon footprint or provide wider environmental benefits.”

Social interventions targeting pharmaceuticals might include:

• Awareness campaigns to highlight the correct disposal of unused pharmaceuticals, which does not include flushing or binning. Instead, medicines should be returned to pharmacies.
• Green prescribing, where if several medicines of equal therapeutic benefit are available, the one with the least environmental impact is prescribed.
• Social prescribing, where doctors are encouraged to refer patients to local, non-clinical services where activities known to improve health and wellbeing are offered. Under such a scheme, patients considered not-at-risk are prescribed medicines as a second resort.

The state of our waters

Up to 90% of pharmaceuticals can be removed from wastewater during treatment processes, however, globally, over 600 pharmaceutical substances have been identified in aquatic environments. Pharmaceuticals in treated wastewater effluent are not currently regulated in the UK, but wastewater is sometimes analysed to track a population’s health as seen through their use of pharmaceuticals (such as antibiotics and painkillers) and other biochemicals. This makes sense: treated wastewater is the main pathway by which medicines and their metabolites enter the aquatic environment.

When a person swallows a medicine or other man-made substance, the ingested compounds are degraded by the body but not completely absorbed. The elements that aren’t broken down end up going through the sewage treatment process – which is not always effective in the removal of all organic matter in wastewater – and is then released into rivers, lakes and soils.

The bigger the population, the bigger the problem

For the new study, researchers ‘mined’ various chemical and biological agents from rivers and wastewater to determine the impact on ‘receiving’ waters, such as rivers, of various industrial chemicals (bisphenol A in plastics), personal care products (UV filters and preservatives in cosmetics), pesticides, illicit drugs, lifestyle chemicals (such as caffeine and nicotine), prescription medicines and genetic material (e.g. antibiotic resistance genes).

The five cities and towns used in the study (Bath, Bristol, Chippenham, Keynsham and Trowbridge) have different characteristics including population size, industry presence and socioeconomic status.

“We found that wastewater represents an excellent fingerprint of a city’s use of a complex mixture of substances of biological and chemical origin,” said Professor Barbara Kasprzyk-Hordern.

The biggest offenders identified in the study were painkillers and medications used for heart disease, mental-health conditions and epilepsy (all non-communicable conditions) along with antibiotics (known to contribute to the prevalence of antibiotic-resistance), lifestyle chemicals such as caffeine, and substances produced when these compounds are broken down by the body.

Professor Barbara Kasprzyk-Hordern said: “What is clear from this study is that we, as individuals, share the environmental burden in the catchment. Our lifestyle choices – linked with the household and beauty products we use, and the pharmaceuticals we consume, have a direct impact on the surrounding environment.

“Most of us are unaware of this impact because each use of a product results in small parts-per-billion quantities of toxic waste that can’t be seen with a naked eye, but when taken together, these tiny quantities create a complex chemical cocktail in our rivers that might have detrimental effects on the wider environment, especially aquatic creatures.”

Professor Julie Barnett, Associate Pro-Vice-Chancellor (Research) at Bath, and leader of the social science work on the project, added: “There is considerable scope for changes in prescribing practices to have an impact on environmental health. Which pharmaceuticals are prescribed or de-prescribed, whether a social prescription may be appropriate and how we dispose of unused pharmaceuticals are all areas where changes can make important differences to the health of the wider environment.”

This study was a collaboration between the University of Bath, Wessex Water, and Bath and North East Somerset (B&NES) Council. ENTRUST: Wastewater fingerprinting for public health assessment was co-funded by Wessex Water through the University of Bath’s EPSRC Impact Acceleration Account.