Routine monitoring at sewage treatment works could provide a powerful early warning system for the next influenza or norovirus epidemic.
In the first large-scale and comprehensive wastewater-based epidemiology (WBE) study in the UK, researchers at Bangor University, University of Bath and the UK Heath Security Agency analysed wastewater from 10 cities, looking for chemical and biological markers of health, including pesticides, pharmaceuticals and disease-causing viruses. The work was supported by the Engineering and Physical Sciences Research Council (EPSRC) and the UK Health Security Agency.
The researchers collected samples from each location at hourly intervals over 24 hours on nine days in November 2021. The samples for each day were pooled before being processed and analysed for trace chemical markers using mass spectrometry techniques. The samples were also analysed to detect any genetic material from viruses (SARS-CoV-2, norovirus and adenovirus). The total sampling catchment area equated to a population of around seven million people.
Using highly sensitive chemical analysis that could distinguish between very similar markers, the researchers were able to tell whether pharmaceuticals had passed through the human body, had been directly disposed into the wastewater system, and could also identify whether chemicals such as pesticides had been ingested through food or had washed into the wastewater system from agricultural land.
The team observed that differences in levels of chemical markers were mostly dependent on the size of population in the catchment area, but there were some outliers. For example, in one city there was a much higher concentration of ibuprofen found in the water, compared with other cities, suggesting direct disposal from industrial waste.
The researchers detected localised outbreaks of norovirus, SARS-CoV-2 and influenza, but could also correlate them with spikes in usage of over-the-counter painkillers such as paracetamol. The results indicate that analysing wastewater on a large scale in this way, dubbed WBE, could spot new outbreaks of diseases in communities early on, before large numbers were admitted to hospitals.
The study is published in the Journal of Hazardous Materials.