Determining a community’s health status anonymously, without surveys, without urine samples, and in near real time, has long been the ambition of epidemiologists. Today, researchers have a practical path to this vision. A team from the University of Bath in the United Kingdom has developed a tool with the potential to turn this dream into a reliable reality.
For 15 years, Professor Barbara Kasprzyk-Hordern and colleagues at the Institute for Sustainability and the Center for Water Research and Innovation at Bath have advanced wastewater-based epidemiology, or WBE. This approach analyzes wastewater from entire communities to track more than 100 chemicals, health indicators, disease markers, patterns of drug use, and human exposure to hazardous substances that can impact health or the environment.
WBE aligns with the One Health concept by connecting human health, animal health, and environmental conditions. It holds promise for a wide range of health questions, including monitoring the spread of new outbreaks, assessing prescription and illicit drug use, measuring exposure to alcohol or tobacco, and even identifying pesticides entering the system through food pathways.
Compared with traditional epidemiological studies, WBE offers distinct advantages. It does not rely on voluntary questionnaires or individual sample submissions. The data can reflect a broad community picture with less dependence on participant response rates, and it can be generated at high speed across multiple sites with ongoing collection rather than sporadic sampling.
Illicit drug use in Europe
Testing wastewater can be described as a highly diluted, pooled urine sample representing a community. It serves as a fingerprint of the community’s overall health and lifestyle, according to Kasprzyk-Hordern. Data collected through WBE can be both comprehensive and anonymous, enabling continuous processing that supports near real time insights.
The work demonstrates how wastewater analysis captures trends in drug use, including substances such as cocaine, within a community. The ongoing capability of WBE provides the potential to observe changing patterns in antimicrobial use and resistance, and to monitor shifts in public health risk profiles with minimal disruption to daily life. This is illustrated in the Bath program and summarized in related research literature.
The technology has also grown in scope beyond drug use. In recent years, WBE has helped track risks to public and environmental health, including surveillance for COVID-19 and the spread of antibiotic resistance. It offers a framework for early warning of emerging health threats and can support informed public health decisions across regions.
How does this technology work? It is conceptually straightforward, yet methodologically sophisticated. Water samples are collected from rivers or wastewater treatment facilities. The sampling strategy depends on the investigation, but samples are typically gathered at regular intervals around the clock and then combined for analysis.
After removing solid particles, the target chemicals are isolated from the wastewater. The samples are concentrated and analyzed with techniques such as liquid chromatography and mass spectrometry. This enables precise quantification and the identification of each chemical component by a unique fingerprint.
Researchers have developed methods to analyze more than 100 targets simultaneously, which saves time and resources and supports broad target profiling. This capacity is crucial for a comprehensive view of community health biomarkers.
For example, a repository of mass spectra helps researchers interpret changing patterns of antimicrobial agent use and resistance. Such a library supports rapid recognition of emerging trends and supports public health responses as new substances enter the market.
Identification of bacteria and viruses
The sensitivity of wastewater-based approaches allows detection of a wide range of molecular signals, from small pharmaceutical residues to larger biomolecules. Bacteria and viruses can also be identified through this method, expanding the scope of community health surveillance.
This capability is especially valuable when examining a population’s exposure to environmental pollutants that may relate to diseases such as cancer or metabolic disorders. Chemicals found in household products, personal care items, and food contaminants can reveal patterns of exposure and potential health risks, including the presence of antimicrobial resistance and other public health concerns.
Researchers analyze various biomarkers produced by the body, such as ammonia, caffeine, or nicotine, to estimate the number of contributors to the sample. Dilution by rain is accounted for with mathematical models to improve the accuracy of the estimates and to normalize data across time and space.
The eWBE effort traces back 15 years, when the Bath team began examining illicit drugs released into the environment via sewage. Since then, analyses have covered numerous cities and countries, revealing where chemicals originated and how they traveled through wastewater. This capability also helps identify new drugs entering the market and alerts public health authorities to evolving risks.
In the broader scientific community, the Bath program contributes valuable methods and reference data, including mass spectra repositories that support interpretation of changing drug-use patterns and antimicrobial resistance signals. Such resources are essential as the field scales to more cities and longer timeframes, enabling researchers to spot anomalies and respond proactively.
As the field evolves, the emphasis remains on building robust, transparent methods that support decision making while protecting privacy. The ongoing work of the Bath team and collaborators continues to shape how WBE can be deployed as part of integrated health monitoring systems across Canada, the United States, and beyond. Marked citations to the work of Kasprzyk-Hordern and colleagues appear in the emerging literature and research summaries for readers seeking authoritative background.