C05027: Scoping study on the impact of a variety of watercourse pollution incidents (non-radioactive) on food safety

Study Duration: September 2001 to August 2002

Contractor: Centre for Ecology and Hydrology

Watercourse pollution incidents can potentially affect the safety of aquatic foodstuffs and terrestrial foodstuffs which come into contact with contaminated water or sediments, for example by flooding or irrigation. There is not currently a standard method for measuring the impact of these pollution incidents. The aim of this scoping study is to look at methods of assessing the impact of watercourse pollution incidents using existing knowledge of transport pathways and existing approaches for modelling dispersion of pollutants in watercourses. As a result of this study recommendations will be made for appropriate (simplified) methods of assessing potential impact in the event of a future incident.

The Centre for Hydrology and Ecology will cover three specific areas in this scoping study.

(1) Review of past watercourse pollution incidents and their impact on food safety.

Extensive previous studies of industrial accidents will be used to collate information on past watercourse pollution incidents. In addition, published studies by the Environment Agency of watercourse pollution incidents will be utilised. This information will be reviewed and pollution incidents will be categorised, as far as possible by released scenario, pathways to foodstuffs and contaminant type.

(2) Identification of pathways, modelling approaches and data requirements.

The study will consider requirements for assessment of the impact of the following classes of potential pollutants (both chemical and biological):

• Pesticides
• Oil spills
• Chemical spills
• Raw sewage spills

In the light of the review of previous pollution incidents, the transport mechanisms of different pollutants in the watercourses will be investigated, with particular emphasis on the importance of particle affinity, and dilution/dispersion in the watercourse. Methods of classifying pollutants into groups of different particle affinity will be investigated. The proposed study will also consider approaches for assessing the impact of watercourse pollution on milk and meat, crops, fish and aquatic foodstuffs.

(3) Example accident scenario and modelling

A limited assessment of the impacts of the release scenario will be made, considering (i) limits for the pollutant concentration in water used for fish farming; (ii) limits for the pollutant concentration in water used for irrigation; (iii) potential transfers to milk via cattle drinking; (iv) potential transfers to wild fish. Methods of simplifying models will be investigated.

This scoping study has identified a number of recommendations for further work towards the development of a working assessment methodology for watercourse pollution incidents. In particular there is a need for:

• Improved empirical data on the consequences to the food chain of real pollutant releases
• Improved co-ordination of emergency response with the Environment Agency and improved data reporting by the Environment Agency
• Development and parameterisation of simplified assessment models and criteria

It is envisaged that the findings of this work will aid with the assessment of future waterborne pollution incidents. The impact of this project may be more evident upon occurrence of new incidents of this type. Conclusions of the work are being addressed by the Agency.

Final report is available from the FSA Library and Information centre.
To obtain a copy, please contact the Enquiry Desk, Dr Elsie Widdowson Library and Information Services, Food Standards Agency ( Tel: 020 7276 8181/8182 or e-mail: library&info@foodstandards.gsi.gov.uk )

Contact: For any enquiries concerning this research project, please contact the relevant Programme contact or e-mail: science@foodstandards.gsi.gov.uk