title: Application of chemometric methods for assessment and modelling of microbiological quality data concerning coastal bathing water in Greece.
abstract: BACKGROUND
  Worldwide, the aim of managing water is to safeguard human health whilst maintaining sustainable aquatic and associated terrestrial, ecosystems. Because human enteric viruses are the most likely pathogens responsible for waterborne diseases from recreational water use, but detection methods are complex and costly for routine monitoring, it is of great interest to determine the quality of coastal bathing water with a minimum cost and maximum safety.
  
  
  METHODS
  This study handles the assessment and modelling of the microbiological quality data of 2149 seawater bathing areas in Greece over 10-year period (1997-2006) by chemometric methods.
  
  
  RESULTS
  Cluster analysis results indicated that the studied bathing beaches are classified in accordance with the seasonality in three groups. Factor analysis was applied to investigate possible determining factors in the groups resulted from the cluster analysis, and also two new parameters were created in each group; VF1 includes E. coli, faecal coliforms and total coliforms and VF2 includes faecal streptococci/enterococci. By applying the cluster analysis in each seasonal group, three new groups of coasts were generated, group A (ultraclean), group B (clean) and group C (contaminated).
  
  
  CONCLUSIONS
  The above analysis is confirmed by the application of discriminant analysis, and proves that chemometric methods are useful tools for assessment and modeling microbiological quality data of coastal bathing water on a large scale, and thus could attribute to effective and economical monitoring of the quality of coastal bathing water in a country with a big number of bathing coasts, like Greece. Significance for public healthThe microbiological protection of coastal bathing water quality is of great interest for the public health authorities as well as for the economy. The present study proves that this protection can be achieved by monitoring only two microbiological parameters, E. coli and faecal streptococci/enterococci instead four microbiological parameters (the two mentioned above plus Total coliforms and Faecal coliforms) that are usually monitored today. As a consequence, countries, especially those with large quantities of coastal bathing sites, can perform microbiological monitoring of their bathing waters by checking only the mentioned two parameters, thus ensuring economies of scale. Thus, funds can be used in other actions to preserve the quality of coastal water and human health. This in turn, would aid in the assessment of the quality of coastal bathing waters and provide a more timely indication of bathing water quality, hence contributing to the immediate health protection of bathers.
authors.affiliation: Department of Medical Laboratories, Technological Education Institute of Thessaly , Greece.
authors.forename: Agelos
authors.initials: A
authors.lastname: Papaioannou
authors.affiliation: Department of Animal Production, Technological Education Institute of Thessaly , Greece.
authors.forename: George
authors.initials: G
authors.lastname: Rigas
authors.affiliation: NHS Trust Microbiology Department, United Lincolnshire Hospitals, Lincoln County Hospital , United Kingdom.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Papastergiou
authors.affiliation: Department of Hygiene and Epidemiology, School of Medicine, University of Thessaly , Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Hadjichristodoulou
keywords: Mediterranean; bacterial indicators; chemometric methods; coastal bathing quality; public health