GOING UNDERGROUND: HUMAN PATHOGENS IN THE SOIL-WATER ENVIRONMENT
Lead Research Organisation:
University of Sheffield
Department Name: Civil and Structural Engineering
Abstract
Outbreaks of human pathogens such as Escherichia coli O157 (E. coli) attract media attention due to the potentially severe threat to health and life. Contaminated food is not the only source of infection. Microbial pathogens are widespread in both rural and urban environments and the soils and water resources around us may act as stores or pathways for movement of these organisms. At present, the problem is best understood in a rural context where farm animals provide a source of pathogens to the environment via their wastes. Previous work shows how pathogens survive and move through soils and provides information on their abundance at source and in vulnerable 'receptors' such as rivers, reservoirs and shallow wells. More recent 'catchment scale' models are able to relate variations in agricultural land use (which affects pathogen input, survival and movement) to pathogen levels in areas downstream, such as coastal bathing waters and shellfish beds. Trends in climate, urban development, water resource policy and human attitudes towards health and environmental hazards may increase the potential risk from human pathogens in soil and water resources. An increase in flooding, abstraction of groundwater, use of the canal and river network to distribute water around the country, and reuse of lightly treated 'grey' water may affect the pathogen load of the water and soils we use in towns and cities as well as rural areas. Other potential sources are leaking sewers, fly-tipping and even accidental or deliberate release of pathogens from industry or 'bio-terrorism'. In order to assess and manage this general environmental risk we need to identify and address many scientific, epidemiological and policy questions which are currently unanswered. These include: What soil microenvironments might prolong pathogen survival? How does changing soil water content affect pathogen movement and storage in soils? Will soils store and transport hazardous microbes after air or surface contamination has dispersed? Can we measure the current health effects of environmental pathogen contamination in the general population? Is the hazard acute (due to single events) or chronic (due to background contamination)? How will climate change, shifts in land use and extreme events affect the spatial distribution of pathogen sources and receptors? Are urban populations more vulnerable to pathogens than rural populations through lack of exposure? What activities or social factors might increase a person's level of vulnerability? How should planning and health protection measures be constructed to pre-empt future health risks from pathogens in the soil-water environment? To respond to these challenges we require a broad skills base covering microbiology and the physical processes of pathogen interactions with soil and water; catchment risk assessment; water resource management; human health and epidemiology; and environmental / public health policy. This proposal will convene 5 themed meetings over a 15 month period involving a core interdisciplinary Working Group and additional invited expertise. The outcomes will be: a comprehensive critical review of the current state of the science, risks and policy in the UK, published in a high quality peer-reviewed journal; a detailed set of recommendations for research priorities and policy directions; and at least one proposal for a larger-scale interdisciplinary research consortium based on the outcomes of the review.
Organisations
People |
ORCID iD |
| Steven Banwart (Principal Investigator) |
Publications
Bridge JW
(2010)
Engaging with the water sector for public health benefits: waterborne pathogens and diseases in developed countries.
in Bulletin of the World Health Organization
Bridge JW
(2007)
High-resolution measurement of pore saturation and colloid removal efficiency in quartz sand using fluorescence imaging.
in Environmental science & technology
Bridge JW
(2009)
Measurement of colloid mobilization and redeposition during drainage in quartz sand.
in Environmental science & technology
| Description | The Going Underground project convened a series of residential workshops which brought together experts from a range of environmental, biological, health and social science disciplines to identify and prioritise key areas for interdisciplinary research to improve our understanding and management of pathogen hazards arising within SWEs. The programme of workshops (21/22 November 2007, Sheffield; 16/17 January 2008, Lancaster; 21/22 May 2008, Defra, London) was completed successfully and initial results were presented in an invited contribution to the Canadian Water Network Pathogens-in-Groundwater meeting in September 2008. |
| Exploitation Route | Identification of fundamental cross-disciplinary themes for further research (i) The Environmental Pathogen Cycle. Understanding the critical drivers of pathogen loads, survival rates, transfer of cells and genetic material, and infectivity through Soil-Water-Environment matrices coupled with the development of reliable and specific measurement and monitoring techniques; (ii) Risk Assessment. Transformation of field data and theoretical understanding into a basis for informed risk assessment that responds to catchment dynamics coupled with an improved understanding of infection rates and environmental risk factors in human populations; (iii) Decision Support. Translation of risks into socio-economic costs to support decision-making and create management responses that extend 'beyond compliance' coupled with a more sophisticated approach to driving development of the legislative and policy framework itself. Identification of critical knowledge gaps In summary: a severe lack of inter-comparable data on the survival and transport of pathogenic species in soil-water environments combines with a low level of disease reporting to make risk assessment and management a complex exercise with a small evidence-base. An inability to robustly or cost-effectively trace organisms through the environment and into the population, and vice versa, further constricts efforts to validate or verify transport and infection risk models. Stringent regulation of water quality is driven by a strong political awareness of the health and 'emergency' costs of waterborne pathogens, but outbreaks continue to occur because pathogen loads are not predictable, risk modelling and environmental sampling protocols are based on other contaminants which may behave differently, and infrastructure is therefore not flexible to respond proactively to changing hazard levels before exposures occur. These knowledge gaps are compounded by a poor understanding of the full range of socio-economic impacts both of environmental pathogens themselves and of mitigation options chosen to comply with legislation, over and above the protection of human health in real terms or broader quality-of-life factors. Key recommendations (i) Co-ordinated systematic audits of research across environmental, social and health science disciplines to provide a detailed inventory of practitioners, resources, methods, datasets and perceived objectives within this diverse field; (ii) identification and dissemination of Best Practices (BPs) in science-social science joint working on environmental and zoonotic pathogen hazards (iii) a multi-agency review of British, European and international standards in sampling and analysis, data handling and reporting for pathogens and indicator organisms (iv) additional case-control studies on the role of environmental factors driving infection in populations, (v) continued development of ready-to-use, fully-costed risk management tools which combine data with expert knowledge and uncertainty analyses to aid decision-making for pathogen hazard mitigation. Capacity-building and career development The work outlined above provides a substantial case-for-support for a range of interdisciplinary research, relevant to current RCUK priorities, e.g. in the area of the ecology of infectious diseases. Strong involvement of industrial and governmental stakeholders in the project will facilitate the uptake of the practical recommendations outlined above. While working on the project, the researcher co-investigator has completed his PhD and gained considerable early career experience in research planning, project management and interdisciplinary collaborative working. |
| Sectors | Environment |
| URL | https://www.sheffield.ac.uk/going-underground |
| Description | The findings of the project were invited as a Perspectives article at the science-policy interface by the Bulletin of the World Health Organisation. Bridge J.W., Oliver D.M., Chadwick D., Godfray H.C.J., Heathwaite, A.L., Kay D., Maheswaran R., McGonigle D.F., Nichols G., Pickup R., Porter J., Wastling J. and Banwart S.A. (2010). Engaging with environmental science for public health benefits: waterborne pathogens and diseases in the developed world. Invited Perspectives article, Bulletin of the World Health Organisation, 88, 873-875. Partners of the project utilised the outputs to inform public policy within the government agencies they represented including: Defra, The Environment Agency of England and Wales, and The Health Protection Agency. |
| First Year Of Impact | 2010 |
| Sector | Environment |
| Impact Types | Economic |