Epibathe Accessible Report FP6 Reference 022618

i 

# ACCESSIBLE REPORT

TO COMMISSION STAFF RESPON SIBLE FOR REPORTING TO THE

PARLIAMENT AND TO THE COUNCI L UNDER ARTICLE 14 OF THE

BATHING WATER DIRECTIVE OF 15 TH FEBRUARY 2006

EU FRAMEWORK 6

SPECIFIC TARGETTED RESEARCH PROJECT



# EPIBATHE

PROJECT REFERENCE 022618

MAY 2009

This Activity Report covers the period

1 st

June 2007 to 31st March 2009

All correspondence to:-

Epibathe Coordinator Professor David Kay University of Wales Aberystwyth dvk@aber.ac.uk +44 1570 423565 (Tel and Fax)Epibathe Accessible Report FP6 Reference 022618

ii 

# Contents

1 Context of this report 1

2 Report structure 1

3 Project rationale 1

4 Project partners 1

5 Methodology 2

5.1 Fieldwork 2

5.2 Data available for analysis 3

6 Results 3

6.1 Summary of principal findings 3

6.2 Field sites 4

6.3 Results of epidemiological data analysis 5

6.4 Risk assessment for marine waters 9

7 Conclusions 11

8 Access to the full data analysis 12Epibathe Accessible Report FP6 Reference 022618

1 

## 1 Context of this report

This Supplement 1 to the Epibathe project final report (see Workpackage 9 of the Description of Work) is designed to distil th e central lessons of th e Epibathe project to inform Commission Officers in drafting their report to the Parliament and the Council as required under Article 14 of Directive 2006/7/EC 2

.

A concise report, accessible to the interested ‘lay’ reader, has been requested. To this end, we highlight and illustra te the main findings of the Epibathe project in this report. Readers wishing to explore the detailed scientif ic findings, and statistical analyses undertaken to derive the conc lusions, can access reports, presentations and meeting minutes at

http://www.epibathe.eu/



## 2 Structure of this report

This report provides a brief description of the Epibathe project (Sections 3-5) and outlines the main findings (Sections 6-7) as well as guiding the reader to the principal data which underpins this assessment.



## 3 Project rationale

Epibathe was funded under EU Framework programme 6 to produce ‘science support for policy’. It was commenced in Decem ber 2005 and was completed in March 2009. The imperative for this research effort was the relative paucity of EU data describing the health effects of bathing in EU fres hwaters and Mediterranean marine waters. Both environments provide important recreational resources throughout the Community. In formulating the water quali ty criteria, defined in the 2006 Bathing

Water Directive 2 , it was felt prudent that the Co mmission should seek to initiate research into this aspect of bathing water regulation a nd this aim was drafted into

Article 14 of the Directive.



## 4 Project Partners

The consortium which undertook the Epibathe project is outlined in Table 1. The coordinating institution was UWA. Field in vestigations in Hungary and Spain were undertaken by NIEH and URV respectivel y. The principal responsibility for epidemiological data analysis was with NPHS. UEA provided training materials and

advice on ethical clearance and WHO undertook literature evaluations and ensured the Epibathe outcomes were effectively assi milated within WHO policy developments

1 See Project Reporting in FP6 (2004), Section 6.9, Page 17

2 Anon (2006) Directive 2006/7/EC of the European Parliament and of the Council of 15 February 2006 concerning the management of bathing water quality and repealing Directive 76/160/EEC. Official Journal of the European Union L 64 , 37-51.Epibathe Accessible Report FP6 Reference 022618

2 and updating of the WHO Guidelines for Safe Recreational Water Environments (2003) 3 which was undertaken in 2009.

Participant name Short

name Country Leader

University of Wales, Aberystwyth. UWA UK David Kay

Fodor Joszef Orszagos Kozegeszsegugyi Kozpont. (Now named the ‘National Institute for Environmental Health’), Budapest. FJOKK (NIEH) Hungary Kádár Mihály

University of Rovira and Virgili, Reus. URV Spain Maria Figueras

National Public Health Service, Cardiff. NPHS UK Roland Salmon

University of East Anglia, Norwich. UEA UK Paul Hunter

World Health Organisation, Geneva . WHO (UN) Switzerland Jamie Bartram

Table 1 Partners in the Epibathe project team



## 5 Methodology

5.1 Fieldwork

A randomised controlled trial (RCT) prot ocol, as developed during earlier UK 4 and

German 5 investigations, was implemented wh ich mirrors the approach used in developing the scientific basis of current WHO (2003) 6 ‘Guideline’ values. This protocol required a volunt eer group which was taken to a bathing water, randomised into bather and non-bathers, then expose d through ‘normal’ bathing activity, during which time, water quality was closely monito red through detailed sp atial and temporal

measurement of a suite of faecal indicator organisms used to regulate bathing waters. Before, during and after the exposure period, the volunteers were interviewed and the resultant data analysed to investigate any relationships between water quality and health outcomes reported by the volunteers. The experimental protocol required approval by appropriate local ethi cs panels. Eight separate trials were completed, four

3 WHO (2003) Guidelines for safe recreational water environments Volume I . WHO, Geneva. 219p available from http://www.euro.who. int/watsan/Publications/20031021_1.

4 Kay, D., Fleisher, J.M., Salmon, R.L., Jones, F., Wyer, M.D., Godfree, A.F., Zelenauch-Jacquotte, Z. and Shore, R. (1994) Pr edicting the likelihood of gastroenter itis from sea bathing - Results from randomized exposure. The Lancet 344(8927 ), 905-909.

5 Wiedenmann, A., Krüger, P., Dietz, K., López-Pila, J., Regine Szewzyk and Botzenhart, K. (2006) A randomized controlled trial assessing infectious diseas e risks from bathing in fresh recreational waters in relation to the concentration of Escherichia coli, intestinal enterococci, Clostridium perfringens and somatic coliphages. Environmental Health Perspectives 8115 , 1-41.

6 Kay, D., Bartram, J., Pruss, A., Ashbolt, N., Wyer , M.D., Fleisher, J.M., Fewt rell, L., Rogers, A. and Rees, G. (2004) Derivation of numerical values for the World Health Organization guidelines for

recreational waters. Water Research 38(5 ), 1296-1304.Epibathe Accessible Report FP6 Reference 022618

3 in Hungary and four in Spain. Volunteer numbers exceeded targets in all field campaigns which were completed successfully in 2006 and 2007.



### 5.2 Data available for analysis

The new information generated by the Ep ibathe research: i.e. on EU fresh and Mediterranean waters, has been analysed sepa rately and also combined with existing data acquired using the same research me thods in Germany and the United Kingdom. This meta-analysis of the larger data set includes da ta on over 7,000 volunteers who participated in these randomised c ontrolled trials between 1989 and 2007.



## 6 Results

6.1 Summary of principal findings

Water quality encountered during the new H ungarian and Spanish investigations was relatively ‘clean’ as would be expected fr om the choice of sites which were in compliance with the Imperative standard of the EU bath ing Water Directive (1976). However, elevations in symptom reporting in the bather group(s), i.e. when compared to the non-bather group(s), were observed. It was also notable that the background rates of most symptoms, principally gastrointestinal (GI) symptoms, was lower in the Epibathe studies than in previous studi es in the UK and Germany. These temporal differences could be due to improvements in effluent treatment and the general health status of the European population over the 20 year period spanned by these investigations.

The analysis of the combined data set, specifically that component focused on GI symptoms, suggests that enterococci are be st predictor of illness in bathers using

marine waters and Escherichia coli is a better index of GI symptoms in bathers using freshwater. The evidence-base created by th is analysis suggests that exposure to marine recreational waters presents approximately twice the risk associated with fresh waters containing similar faecal indicator organism densities. Furthermore, the new combined analysis suggests similar risk le vels to those assumed in derivation of the original Guidelines for Safe Recreati onal Water Environments by WHO in 2003 and the revised Bathing Water Directive in 2006. Thus, the Epibathe empirical field

studies and combined data anal ysis does not suggest that a change in the water quality standards suggested by either the WHO or the European Union are in need of

revision.

However, the Epibathe project has produced data suggesting signifi cant limitations in the microbiological methods defined in the revised Bathing Wate r Directive (2006). For example, the ‘most probable number’ (MPN) method for E. coli (ISO 9308-3) produced false positive results which could have classified a Mediterranean bathing area as having ‘poor’ quality when the same site would be charac terised as of ‘excellent’ water quality if measured by the ‘membrane filtrati on’ (MF) method (ISO 9308-1). However, the MF method also produ ced significant problematical results generally attributable to its poor selectivity when applied at both the Hungarian freshwater bathing sites a nd at one Mediterranean bathing site influenced by

freshwater contamination.Epibathe Accessible Report FP6 Reference 022618

4 

### 6.2 Field sites
Figure 1 shows the 4 Hungarian sites examined and Figure 2 shows the sites in Spain.

Figure 1 Hungarian sites examined in 2006 and 2007

Figure 2 Spanish sites examined in 2006 and 2007

Water quality, at each field site, was measur ed in each of six marked swim zones at

20 minute intervals. Bathers were asked to remain in the water for a minimum of tenEpibathe Accessible Report FP6 Reference 022618

5 minutes and the water quality experienced at the time and place of bathing was attributed to each bather. This provided a range of ‘exposures’, i.e. over time and space, both between sites and within each three hour exposure period. Figure 3 shows the range in water quality as measured by enterococci concentrations for all sites examined. (For a full analysis see Appe ndix 6 Epibathe Final Activity Report).

Figure 3 Enterococci concentration measured at each of the Epibathe trial sites

in 2006 and 200 7



### 6.3 Results of the Epidemiological data analysis relating water quality to health outcomes

Five separate analyses have been comple ted to examine the following relationships

and associations:

i. risk of gastroenteritis from recreational bathing water: analysis of Epibathe data from Hungary and Spain;

ii. risk of gastroenteritis from recreationa l bathing water: a meta-analysis of randomised exposure trials in four European countries;

iii. estimating the risk of gastroenteritis in European fresh bathing waters using E.

coli as indicator organism;

iv. risks of non-enteric diseases from Eur opean recreational ba thing water; and

v. the effects of non-water related ri sk factors on gastroenteritis.Epibathe Accessible Report FP6 Reference 022618

6 For a full analysis, see Appendix 2 of the Ep ibathe Final Activity Report. A total of 17 randomised controlled trial experiments were available for this analysis, eight of which were funded under the Epibathe proj ect. The populations of bathing and nonbathing volunteers who participated in th ese trials and provided usable data are

outlined in Table 2 below.

Classification GI AFRI Ear Eye Skin

Non-bathers (n) 3,780 3,953 3,943 3,939 3,590

Bathers (n) 3,432 3,580 3,563 3,557 3,246

Table 2 Population numbers available for the epidemiological analyses using the

combined EU data set.

For EU marine waters (Spain and the UK), the clearest trend in increasing risk of illness with decreasing water quality was evid ent using enterococci as indicator of water quality. Table 3 shows a meta-analysis us ed to calculate the Odds Ratio (OR) of gastroenteritis associated with ascendi ng quartile exposures to enterococci.

Subjects Meta-analysis Quartile cut-points (enterococci/100ml) N % ill Adjusted

OR 95% CI

Non-bathers 1,598 6.7 1.00 N/A

0-8 340 7.1 1.35 0.75-2.45

9-27 360 9.7 1.44 0.87-2.36

28-88 357 13.2 1.47 0.94-2.31

≥ 89 357 6.7 2.06 0.84-5.04

Overall 3,012 7.9 1.39 1.03-1.87

Table 3 Meta-analysis used to explore the relationship between reported gastroenteritis in the bather cohort and enterococci conc entration in EU marine bathing waters.

The meta-analysis forest plot for all mari ne sites is presented in Figure 4 below.Epibathe Accessible Report FP6 Reference 022618

7 Figure 4 Forest plots representing the OR (ES (95%CI)) of gastroenteritis in each marine water site (i.e. bather vs non-bather) at different

enterococci concentrations. The dotted line is the mean OR for all sites.

For fresh waters (German and Hungary), the clearest dose-response relationship between gastrointestinal symptoms and water quality was seen with E. coli concentration. Table 4 shows the freshwater analysis. NOTE: Weights are from random effects analysis Overall (I-squared = 0.0%, p = 0.885) Spain II UK I

Spain I UK IV Study

Spain III UK III UK II

Spain IV ID

1.38 (1.03, 1.87) 0.84 (0.38, 1.88) 1.49 (0.69, 3.20)

2.01 (0.79, 5.16) 1.72 (0.71, 4.15)

1.19 (0.51, 2.75) 1.25 (0.59, 2.62) 1.95 (0.72, 5.31)

1.39 (0.58, 3.36) ES (95% CI)

100.00 13.86 15.32

10.11 11.51 %

12.60 16.14 8.96

11.51 Weight

1.38 (1.03, 1.87) 0.84 (0.38, 1.88) 1.49 (0.69, 3.20)

2.01 (0.79, 5.16) 1.72 (0.71, 4.15)

1.19 (0.51, 2.75) 1.25 (0.59, 2.62) 1.95 (0.72, 5.31)

1.39 (0.58, 3.36) ES (95% CI)

100.00 13.86 15.32

10.11 11.51 %

12.60 16.14 8.96

11.51 Weight

1 .1 10Epibathe Accessible Report FP6 Reference 022618

850 unit cutpoints Subjects Meta-analysis

( E. coli /100ml) N % ill Adjusted

OR 95% CI

Non-bathers 2,182 4.7 1.00 N/A

0-49 451 3.3 0.70 0.35-1.39

50-99 565 5.0 1.39 0.82-2.35

100-49 239 5.0 1.23 0.56-2.69

150-199 116 6.0 1.59 0.52-4.88

200-249 65 10.8 1.77 0.65-4.86

≥

250 582 8.1 1.67 1.04-2.67

Overall 4,200 5.2 1.20 0.88-1.62

Table 4 Meta-analysis used to explore the relationship between reported gastroenteritis in th e bather cohort and E. coli concentration in EU fresh bathing waters.

The meta-analysis forest plot for all freshw ater sites is presented in Figure 5 below.

Both analyses (i.e. of fresh and marine wa ters) suggest elevatio ns in illness in the bather cohorts. However, results from fres h water studies do not display a consistent

incremental elevation in odds ratio (OR) as the exposure increase.

It should be noted also that the values presented in Tables 3 and 4 are of single exposure concentrations and they are, theref ore, not directly related to a calculated percentile compliance concentration as is specified in the Bathing Water Directive (2006) and the WHO Guidelin es for Safe Recreational Water Environments (2003).Epibathe Accessible Report FP6 Reference 022618

9 Figure 5 Forest plots representing the OR (ES (95%CI)) of gastroenteritis in each fresh water site (i.e. bather vs non-bather) at different E. coli

concentrations. The dotted line is the mean OR for all sites.



## 6.4 Risk assessment

The original risk assessment wh ich underpinned the WHO Guidelines 7 was derived from the UK studies. This assumed a simp le linear relationship between enterococci

concentration in marine waters and rates of gastroenteritis in bathers. However, the assumption of a single linear relationshi p becomes questionable where several

individual studies are comb ined spanning different regions and time periods. This may result in the rates of illness in th e non-bather groups exhibiting variability between sites and times, which is normal for gastroenteritis in the community. It was for this reason that the epidemiological analysis summarised above adopted a ‘metaanalysis’ approach, rather than reporting a linear modelli ng analysis. Furthermore,

7 Kay, D., Bartram, J., Pruss, A., Ashbolt, N., Wyer, M.D., Fleisher, J.M., Fewtrell, L., Rogers, A. and Rees, G. (2004) Derivation of numerical values for the World Health Organization guidelines for

recreational waters. Water Research 38(5 ), 1296-1304. NOTE: Weights are from random effects analysis Overall (I-squared = 0.0%, p = 0.483) Germany II

Germany III

Hungary III Hungary II Study

Germany V Germany IV ID

Hungary I Germany I

Hungary IV

1.19 (0.88, 1.62) 1.28 (0.53, 3.10)

1.60 (0.57, 4.52)

1.03 (0.32, 3.28) 0.53 (0.17, 1.66) 0.93 (0.47, 1.85) 2.05 (1.01, 4.16) ES (95% CI)

1.11 (0.49, 2.47) 0.58 (0.17, 1.98)

2.32 (0.65, 8.28)

100.00 12.03

8.67

7.00 7.24 %

19.88 18.79 Weight

14.49 6.14

5.76

1.19 (0.88, 1.62) 1.28 (0.53, 3.10)

1.60 (0.57, 4.52)

1.03 (0.32, 3.28) 0.53 (0.17, 1.66) 0.93 (0.47, 1.85) 2.05 (1.01, 4.16) ES (95% CI)

1.11 (0.49, 2.47) 0.58 (0.17, 1.98)

2.32 (0.65, 8.28)

100.00 12.03

8.67

7.00 7.24 %

19.88 18.79 Weight

14.49 6.14

5.76

1 .1 10Epibathe Accessible Report FP6 Reference 022618

10 risk assessment in the period since the WHO analysis was completed as advanced. In particular, assumptions of simple linear relationships have been replaced by approaches which assume that the ‘drivers’ (e.g. enterococci in ma rine waters) of an outcome (e.g. gastroenteritis rates in a bather group) are better described as statistical distributions, rather than i ndividual values. Expressed in risk assessment terminology, linear modelling has been replaced by stoc hastic modelling in ma ny areas of health

risk assessment.

The concluding International Workshop of th e Epibathe project was conducted at the WHO head quarters in Geneva in January 2009 and the choice of risk assessment approaches was addressed. The participati ng expert group agreed that a stochastic approach to risk assessment was most appropr iate and this was applied to the Epibathe data by Professor Paul Hunter (Epibathe partner UEA). The advantages of this approach are that the modelling of risk can be accomplished without the need to make certain, potentially over-simplistic, assumptions in the underlying data 8 . Instead, the input ‘drivers’ can be expresse d as statistical distributions , which is generally a more realistic representation of reality.

Using this approach, the risk of gastroenteri tis attributable to bathing in EU marine waters (i.e. using the UK and Spanish data sets combined; see Figure 4) which have a

95 th percentile water quality of 200 enteroco cci per 100ml was calculated at 4.5% (see Figure 6).

Figure 6 Stochastic model of the attributable risk of gastroenteritis experienced by bathers in marine waters with a 95 th percentile value of 200 enterococci per 100ml 9

.

8 For example, the original WHO assessment made th e assumption that all beaches world-wide had the same standard deviation for enterococci sampled in the bathing zone, i.e. a log10 value of 0.8103.

9 This analysis was completed using Monte Carlo simulation within @RISK software of Palisade Corp. 2.5% 95.0% 2.5% -2.0 21.1-20020406080100120 0.00 0.02 0.04 0.06 0.08 0.10 0.12 Attributable disease incidence

A ttributable disease

incidence

Minimum -5.5842

Maximum 100.8291

Mean 4.4952

Std Dev 6.1587

V alues 10000Epibathe Accessible Report FP6 Reference 022618

11 This value is comparable with an attri butable illness probability of 5%, calculated using the original WHO analysis which underpins the WHO 10 ‘ Level B ’ and EU 11

‘ Good ’ criteria for this parameter.

This broad correspondence between the risks derived from the new information for marine waters, generated through the Epibat he project analysed using contemporary approaches, and the risks assumed by the de signers of the existing standards, led the WHO expert group to conclude that there was no evidence -base to suggest that the original criteria should be amended in response to any more recent epidemiological information. This recommendation is encapsulated within an addendum to the 2003 WHO Guidelines which will shortly be published by WHO.

For EU freshwaters, the increase in illness rates attributable to incremental elevations

of faecal indicator bacterial concentrations was less marked, as seen in Table 4 above. The attributable risks were best characterised by Escherichia coli , rather than enterococci, bacteria which is in broad agr eement with parallel research in the USA. The Epibathe analysis would suggest that th e risks of bathing in freshwaters is lower than attributable to marine water exposures and that the 2:1 risks differential, implied by the stricter standards for marine wate rs, outlined in Annex 1 of the 2006 Bathing Water Directive, is in broad agreement with the finding of the Epibathe project.



## 7 Conclusions

1. The Epibathe project has provided new in formation to supplement the original UK data used to underpin the WHO Gu idelines for recreational waters published in 2003.

2. This information, together with new da ta for the USA, has been evaluated by WHO in January 2009 during an expert c onsultation to consider revision of the WHO Guidelines in this area from which elements of the EU Bathing Water Directive (2006) criteria derive.

3. A new approach to assessing the risks attr ibutable to bathing in environmental waters was applied to the Epibathe data and reported to the WHO expert meeting in January 2009.

4. This analysis suggested that ther e was broad correspondence between the attributable risks assumed in deriving the current WHO and EU standards with that calculated using the new informati on derived from the Epibathe project.

5. The new research has not, therefore, produced a clear evidence-base which would suggest that a revision of the wa ter quality criteria outlined in Annex 1 of the 2006 Bathing Water Dire ctive should be undertaken.

6. The risks attributable to bathing in freshwaters were less marked than in marine water environments. This sugges ts that a differential in standards applied to both environments, as is evident in the 2006 Bathing Water Directive, is supported by the ava ilable and newly derived evidence.

10 See Tale 4.7: WHO (2003) Guidelines for safe recreational water environments Volume I . WHO, Geneva. 219p available from http://www.eur o.who.int/watsan/Publications/20031021_1.

11 See Annex 1: Anon (2006) Directive 2006/7/EC of the European Parliament and of the Council of 15 February 2006 concerning the management of bathing water quality and repealing Directive

76/160/EEC. Official Journal of the European Union L 64 , 37-51.Epibathe Accessible Report FP6 Reference 022618

12 

## 8 Access to the full data analysis

The full data analysis in the form of the fi ve reports noted in Section 6.3 above can be obtained as separate .pdf downloa ds from the web site below:

http://www.epibathe.eu/