Identifying Health Risks Associated with Recreational Bathing Waters

recreational swimming in a Bristol, UK, lake


The European Bathing Directive aims to improve and preserve recreational waters to protect the health of swimmers by setting water quality standards. The Directive was most recently revised in 2006 based on epidemiological research conducted by the World Health Organisation (WHO) in 2003.


RAND Europe, in collaboration with Professor David Kay at the Centre for Research into Environment and Health and Alan Lyne of ADAS, conducted a rapid evidence assessment of published and unpublished studies to update the UK Department for Environment, Food and Rural Affairs (Defra) on the most recent research that evaluates the relationship between recreational bathing waters and gastrointestinal illness. Specifically the study aimed to answer two research questions:

  1. What is the post-2003 evidence for the health risks of recreational bathing in general, and to specific groups of bather in particular?; and
  2. What is the evidence to support the different classification standards outlined in the European Bathing Directive?


  • Based on 16 studies published since 2003, there appears to be little or no significant difference between gastrointestinal illness (GI) in bathers compared with non-bathers at marine beaches. In contrast, there appears to be a consistent and significantly higher risk of GI in bathers compared with non-bathers in freshwater sites in temperate climates (up to 3.2 times higher).
  • There is some evidence to suggest that increased bather exposure (i.e. head immersion or swallowing water) results in a higher risk of GI, particularly for freshwater bathers.
  • Very high levels of pollution due to heavy rainfall and urban run-off or sewage contamination are associated with increased GI.
  • There is not, as yet, a coherent body of knowledge which would suggest a need to change the current water quality standards specified in the 2006/7/EC European Bathing Waters Directive.
  • More epidemiological evidence is needed to disprove or confirm the findings of the original studies that were used to derive the water quality standards in the 2006/7/EC Bathing Waters Directive, in particular for marine waters, before the Directive is reviewed in 2020.

Published Research

Project Team

RAND Europe

Sarah King
Josephine Exley
Eleanor Winpenny
Marie-Louise Henham


Alan Lyne, ADAS
David Kaye, Centre for Research into Environment and Health