Research and analysis

Overview of potential human pathogens in the environment: summary

Published 24 October 2024

Applies to England

1. Chief Scientist’s Group report summary

This project reviewed pathogens to which people can be exposed through water, land and air, now and in the future. The project also conducted a preliminary assessment of the relative likelihood of infection and potential impact of these pathogens.

1.1 Background

The recent Covid-19 pandemic has brought increased interest in the incidence, transmission, and risks from (emerging) pathogens. This includes the role of the environment in transmission of pathogens to humans. The Environment Agency does not carry out routine monitoring for human pathogens in the environment, although Designated Bathing Waters are monitored for faecal indicator organisms that provide an indication of pathogenic risk.

1.2 Approach

The project reviewed monitoring of pathogens in environmental settings in other countries, focusing on nations with a similar climate to the UK, or those with a climate which could be representative of the UK in the future.

The project also considered the relative level of risk from pathogens in the UK environment, including exposure of people via surface waters (ingestion, inhalation), outdoor air (inhalation), vectors (transmission of pathogen via a host species), and solid material such as soil and manure (direct contact, ingestion). The findings were consolidated through a literature review, a questionnaire eliciting expert opinion, and an expert workshop. The Health and Safety Executive’s Approved List of Biological Agents was used as a starting list of pathogens and after screening out some (e.g. some could only be spread via human-to-human contact) 138 remained which were reviewed to reach a hazard rating.

1.3 Results

Some pathogen monitoring for environmental matrices (e.g. soils, and surface waters) was reported for the United States, Canada, Australia, New Zealand and the members of the European Union, but in general all these activities were limited in extent and mostly focused on anthropogenic materials such as compost or on drinking water.

The project identified a wide range of pathogens of concern including some well-known organisms such as Campylobacter species, Escherichia coli shiga-toxin strains (e.g. E. coli O157:H7), and norovirus but also several less obvious organisms, such as Cladophialophora bantiana and tick-borne encephalitis virus.

Some pathogens were identified as not currently present in the UK but would be classed by this hazard assessment as of serious concern if they were to enter the UK.

1.4 Conclusion

The review of efforts in other countries found that the environmental matrices assessed, pathogens monitored and regulatory or guidance limits for those pathogens, were broadly similar and the UK is following common practice. Any further monitoring would need to understand the full range of human exposures to pathogens from a variety of sources.

The expert review approach used may mean that some of the results would change with a different expert panel or modified focus. Nevertheless, the report provides a starting point to improve the risk identification for those organisms identified.

1.5 Publication details

This summary relates to information from project SC220030/R, reported in detail in the following output:

• Title: Overview of potential human pathogens in the environment
• Project manager: Dr China Hanson, Chief Scientist’s Group
• Research contractor: The James Hutton Institute

This project was commissioned by the Environment Agency’s Chief Scientist’s Group, which provides scientific knowledge, tools, and techniques to enable us to protect and manage the environment as effectively as possible.

Enquiries: research@environment-agency.gov.uk.

© Environment Agency