Bathing Water Quality and Health Implications

C Nelson and A T Williams School of Applied Sciences University of Glamorgan

Abstract

Considerable controversy exists with respect to water quality at bathing beaches. In the UK, South Wales beaches appear to be at the forefront regarding these views. An exhaustive study investigating water quality and health was carried out at Barry Island, Wales during the summer tourist season. The beach is a very popular holiday resort and attracts some 850,000 during the summer months. It is composed of fine grained sand backed by a sea wall. Water samples were taken at two hourly intervals between 1 1:00 and 15:00 hours over a 6 day period during a hot August period in 1995. Testing was carried out for faecal colifonns and faecal streptococci. Simultaneously, a very detailed questionnaire (n=1276) was distributed to beach users. The questions related to health, food consumed, family history, entry to the water or not, etc. Ten days later a follow up telephone questionnaire was carried out specifically to find if any person had contacted for example, ear problems, gastrointestinal symptoms etc. Twenty four percent of swimmers had illnesses compared to 5% for non-swimmers. Levels of faecal colifonns and faecal streptococci were found to be significantly high (45,000 and 16,000 respectively per 100ml). The survey was continued in 1996 at three South Wales beaches. Emphasis was placed on public perception of beaches and attitudes to seaside award schemes such as the European Blue Flag, investigating the legislative framework through which water quality is controlled and impact on the beach consumer.

1 Introduction

A case study was carried out on a popular tourist beach in South Wales, investigating quality of the sea water, health implications of bathing and effectiveness of existing regulation protecting beach users. The crux of the matter centres around EEC Directive 76/160 concerning bathing water [1] which is the fundamental piece of legislation applying to all Member States addressing specifically the issue of water quality at recreational sites,.

The Directive has been the cause for much disputation since its introduction over 20 years ago, in 1976. Compliance is based around achieving set values defined

176 Water Pollution for 19 determinands. Two standards are set for most of the parameters, both imperative and the stricter guideline values. Two microbiological parameters are considered to be the most appropriate determinands, total coliforms and escherichia coliforms (E. coli) set at 10,000 and 2,000 per 100ml respectively. In addition to these two indications of sewage contamination, another standard was set for faecal streptococci stipulating a guideline value of 100 per 100ml.

Design of this Directive was aimed at amenity value as much as setting health standards, based on thin epidemiological evidence, one of the main criticisms being selection of inappropriate bacterial indicators [2, 3]. Increasing public awareness over environmental concerns has added to the impetus behind reforms to current legislation over recreational waters. The Directive 76/160 is now under review, causing much discontentment, especially in the UK amongst the privatised water companies. It is likely that the most prominent change will be inclusion of an imperative standard for faecal streptococci, and deletion of the total coliform parameter. Although no fixed value is currently set for faecal streptococci, it is now widely accepted that enterococci is a better indicator of health risk than E.coli [4].

Marine pollution is an emotive issue, high on the environmental agenda in South Wales with the recent oil disaster early in 1996 when the Sea Empress tanker was grounded off the Pembrokeshire coastline spilling circa 70 ktons of crude oil. Two years prior to this environmental catastrophe, saw severe cases of neurological disabling symptoms supposedly contracted from swimming occurring in 2 teenagers, at Oxwich Bay, Gower, Wales, known for its impeccable water quality. Although no causal proof was obtained extrapolating their disease back to the water, speculation has increased over the health risk associated with swimming in coastal waters. The Oxwich cases have been of particular interest due to the Bay's consistent compliance with the current EEC Directive on water quality. The question to be addressed is, 'does current legislation ensure adequate protection of health, on which most of the existing beach award schemes are based, including the Blue Flag Award (6) and the Tidy Britain Group (TBG) Seaside Awards (5)?'

2 Physical background.

2.1 Barry Island Site Description

Whitmore Bay, Barry Island is a popular coastal resort, lying 10 miles West of Cardiff in the Vale of Glamorgan. The beach is predominantly sandy, south facing on the Bristol Channel with a large surface area of 200,000nf, 800m long and 250m wide to low water; OS reference sheet 171, grid reference 115 663. The resort has a highly developed hinterland both commercial and tourist, including a holiday camp, funfair, amusements, shops, pubs and night-clubs.

Tourism is very important to the area, the beach attracting 850,00 people during 1994 [7] and providing 13.4% of the employment sector [8]. The surrounding

town of Barry provides a large catchment with a population of 46 [7], making up 41% of the Borough. The beach coupled with attractions provide a focal point for summer day trips from the surrounding South Wales Valleys and

Gwent region, also being within 10 miles of the M4 motorway, creating easy access for holiday makers.

2.2 Oxwich Bay Site Description

Oxwich Bay, Gower, West Wales is privately owned by the Penrice Estate, a large proportion of which was declared a National Nature Reserve (NNR) in

1962 by the Nature Conservancy Council and includes a Site of Special Scientific Interest. Although the majority of visitors are attracted to Oxwich Bay for its coastline, a substantial number visit the Reserve. Oxwich Bay is a pocket bay consisting of a fine sandy beach, backed by a varied and extensive sand dune

system. Behind the sand dune system is a large freshwater marsh. Wave energy is low. The northern and southern ends of the Bay are flanked by mature broad- leaved woodland. Oxwich point forms the southern boundary of the bay, continuing westwards to Slade Bay following a rocky shoreline with coastal

slopes and limestone cliffs. Oxwich is one of the main locations for tourism on Gower and attracts a large number of water sport users. However, it suffers seasonal trends similar to other bays along the Gower coastline. This adds

pressure to managing conservation at Oxwich because of the increased population during summer months. Holiday facilities exist in the form of a cafe, static caravan sites, hotel and bar. Information [9].

2.3 Langland Bay Site Description

Langland Bay has a fine grained sandy beach which lies in the most intensively used stretch of Gower coastline, West Wales. It is protected on both sides by headlands, the western side siting a golf course, and is backed by beach chalets, tennis courts and a car park, so has low wave energy. The surrounding area includes Bishop's Wood and contains a Local Nature Reserve and 2 Sites of Special Scientific Interest. West Glamorgan County Council has designated the

Bay as an intensive zone aimed at protecting and enhancing the coastline whilst providing facilities to cater for visitors. The Bay and surround provides a cafe and small gift shop selling food and drinks. It is heavily frequented by city residents, tourists which with close proximity to built up areas makes it an ideal destination for day trippers. Langland is also well known for its excellent surf and ideal conditions for water sports. Water based activities which take place include surfing, bathing, canoeing, windsurfing and recreational fishing. Information [9].

2.4 Cefn Sidan Site Description

The beach Cefh Sidan is situated in Pembrey Country Park, an area of circa 2800 ha with a diversity of landscape including saltmarsh, dune system and foreshore. The fine grain sandy beach is large extending 10 km in length from the Pier at Burry Port in the south east to the Gwendraeth Estuary in the north west, backed by a dune system Cefn Sidan is a very popular destination for both locals and holiday makers, receiving 450,000 visitors this year [10,11]. The beach in 1996 was successfully awarded both an Blue Flag and TBG Seaside

Award

3 Methodology

A prospective epidemiological method was employed where participants in the survey were self selecting in their activity on the beach. There are advantages inherent within this type of investigation over a controlled cohort study recruiting volunteers. The main benefit allows analysis across age groups. It is unethical in the cohort study to recruit young children for participation.

Information was collected on the survey days utilising a semi-structured questionnaire to obtain socio-economic data on participants including data on recent dietary habits, contact with members of their family suffering with illness, contact with animals and visits to the beach detailing their behaviour in terms of contact with the sea. This enabled a comparison between the differing levels of sea immersion and a control group consisting of those interviewed who had refrained from entering the water, attempting to eliminate confounding factors. The survey was carried out over a 6 day period in August 1995, during a particularly hot period, temperatures reaching in excess of 24C, water temperature being approximately 19C. The questionnaire requested participants to include their telephone number for use in a follow up telephone questionnaire ten days post the interview at the beach. The telephone questionnaire was conducted to ascertain the number of people who had contracted an illness after visiting Barry Island, to compare the ratios of those who had contact with the sea against those who did not enter the water. Ten days is an average time allow pathogenic organisms contained within sewage contaminated seawater to incubate within the human host. The telephone questionnaire required respondents to provide information on high risk foods eaten since the day at the beach, and again information regarding contact with members of their family suffering with illness, contact with animals and visits to the beach, detailing contact with the sea.

In order to relate health risk of swimming to water quality in an attempt to establish if a dose response relationship existed, samples of sea water were taken on the interview days. The laboratory at the University of Glamorgan was utilised to analyse the water samples using the membranefiltratio n technique

[12], following procedures outlined in the EEC Directive concerning the quality of bathing water. To accommodate proposed amendments to the directive regarding bacterial determination, emphasis was also placed on measuring the

level of faecal streptococci as well as the current criteria for E. Coll. In addition the water was tested for F specific RNA phage using standard procedures at acer Environmental Laboratories and Sciences, Bridgend, Mid Glamorgan. A

window period between the hours 11:00 and 15:00, was identified in which most beach users entered the sea,. Three sets of samples were taken at two points along the beach allowing for spatial variation at the points of highest density of swimmers. By sampling at 11:00, 13:00 and 15:00 on each day for 6 days both

temporal and tidal variation were also accounted for. Samples were taken in knee depth of water, 30 cm below the surface using a sampling pole, in accordance with Environment Procedures [13].

A further survey was completed during 1996 evaluating public perception to beaches and investigating the awareness, recognition and understanding of seaside award systems, and also evaluating whether they play an important role

in beach selection. The survey was carried out through August at three different beach types. Barry Island with a history of poor water quality, Langland (nr Swansea, West Wales) has a better history of water quality, but not attaining the rigid criteria required for the Blue Flag and Cefh Sidan (Pembrey Country Park,

West Wales) with water quality meeting guideline standards set by EEC Directive on bathing water, 76/160, and successfully obtaining both the Blue Flag and TBG Seaside Award A two phase approach was used in the survey. Firstly participants were asked to fill in a questionnaire asking about their knowledge of beach award systems and secondly they were shown photographs of the different types of flags and asked if they could accurately identify each one.

4 Results and Discussion

4.1 Results: Water Quality

The water quality proved to vary widely both temporally and spatially, also being affected by tidal cycles. Barry Island, the survey beach lies on the Severn Estuary, having the second highest rise and fall of the tide in the world (14.7m at

Avonmouth), which may account in part for sewage density fluctuations. Samples taken at the beginning of the week tended to be higher than mid-week samples, which might be due to high visitor loads on the weekend. Very high counts of both E. Coli and faecal streptococci were found. E. Coli averaged

3400/lOOml exceeding the EEC mandatory value by 1.5 times, and faecal streptococci 440/100ml exceeding the EEC guideline value by over 4 times Maximum counts reached a incredible 45,000/lOOml E. Coli and 20,300/100ml. Results for the F specific RNA phage found zero colonies. This could be due to

none being present or due to analytical technique. Research into coliphages is still taking place. Although the EU are considering implementing a standard for these indicators, as yet no definitive determinand exists. However research is still very active in this field. Table 1 outlines the current microbiological parameters set by Directive 76/160 compared to proposed reforms. The bacteriological results substantiate contention over indicator selection. Current evolution in recreational water legislation is placing greater emphasis on defining a faecal streptococci parameter for use in water quality determination, which is believed to be an effective indicator of sewage presence [2,14]. All Member States have to comply to bathing water regulations set by the EC, now under review. Reforms to Directive 76/160 were due to come into force by

December 1995. Continued debate over defining appropriate microbiological parameters is prolonging its implementation.

Kcoli lOOmT' F. streps 100ml-*

Current standard EEC 76/160 Imperative level 2000 — Guide level 100 100

Proposed amendments EC 94/C 112/03 Imperative level 2000 400 Guide level 100 100

Table 1. Some standard current and proposed amendments

100000

10000

100

1 Won 7 TuesS Wted9 Mon14 TuesIS Wed 16

S«mpNng Days during August

Figure 1.Bacterial trends over the study period.

4.2 Results: Questionnaires

The Barry Island survey was carried out over 6 days during August, 1995. The weather was very hot and 1276 questionnaires were obtained. The questionnaires included a request for respondent's telephone numbers used in

the post interview survey necessary for health implications analysis. Five hundred and eighty telephone numbers were submitted of which a total of 535 were contacted.

No consistent relationship appeared to exist between illness rates and bacteria levels, questioning a dose response relationship. These results are in opposition to findings found in previous studies [15,16]. Chi-square analysis was applied to

the data at the 0.05 level showing an increased incidence rate of illness amongst those that entered the water compared to those that refrained from entering, indicating water quality to have a significant effect on contraction of symptoms. Reported illness incidents for swimmers, waders and non swimmers were 24%,

13.8% and 2.3% respectively. There was also a higher incidence rate of illness between waders compared to the non-swimmer group. The symptom rate for swimmers was approximately 24%, which included gastrointestinal problems, skin irritation and sore throats; waders 13.8% and non-swimmers 2.3%.

Children under 10 years of age tended to be the most sensitive to contraction of illness, (38.9% reported ill)) with the 10-20 age group being the most resistant (7%). Figures for the 10-20 age group were 15.8% and for the 30-50 age group, 8.7%. Males had a much higher reported illness rate than females. There was no

obvious reason for this.

4.3 Results: Beach Classification

A recent survey [16] questioned the applicability of the Directive in ensuring safety to bathers, on which seaside award schemes are based, namely the Blue Flag and the TBG Seaside Award Flags. These systems are used in promotion of beaches, but not only is it likely that they may be centred around standards below acceptable limits, additional work done in this survey questioned public perception and awareness of these as marketing tools. Results from the survey work done in 1996 at Barry Island, Langland and Cefh Sidan indicate a great deal of confusion about the different awards available and literature such as the Marine Conservation Society Good Beach Guide. In fact only half of the sample group (52.5%), had heard of any beach award scheme, less thought they understood them and only about 33% accurately identified the criteria for an

Blue Flag. Out of the awards available, the Blue Flag gained the most recognition, 64.5%, compared to 41.4% for TBG Seaside Awards. But when shown a Blue Flag and the TBG Seaside Award Flag as visual stimulus only 10.9% and 0.5% respectively accurately recognised them. In fact 7% of the participants thought the Blue flag represented danger.

These results indicate the ineffectiveness of the flag systems, giving cause for concern, for example in the Green Seas Initiative campaign in Wales [18]. The Green Seas Initiative is a forum set up between various agencies including Welsh Water plc,and Wales Tourist Board. Welsh Water pic. are very pro-active in their attitude to cleaning up the coast, committing huge expenditures to improving the sewerage system [19]. Their role in the Green Seas Initiative campaign is to achieve 50 Blue Flags by the end of the Millenium. So it appears that emphasis is being misplaced by putting importance on seaside award schemes in beach classification.

5 Conclusion

Recent media attention highlighting coastal issues in Wales has brought marine pollution into the limelight, supporting the drive for reform to current legislation on bathing waters, which fall significantly short of standards set by our counterparts in North America [20]. Whilst acknowledging the mono-site limitation of this study in water quality terms, the results are in line with previous research into health implications of bathing in sewage contaminated water [15], indicating swimmers to be at much higher risk of contracting an illness than non- swimmers. Barry Island proved to have high concentrations of faecal bacteria present. Even though a dose response relationship was not established it would be presumptuous to assume one does not exist as these findings are at variance with otherfindings[15,17] . A suggestion would be to continue further work in this field examining a range of beaches with varying water quality and focusing on an intensive microbiological sampling programme.

In addition to health standards which already exist, it is imperative that end user perception be considered as part of beach management or any Integrated Coastal Zone Management scheme. With reference to the lack in recognition of seaside award systems a question which should surely be asked is 'has intellectual arrogance failed to appreciate the major issue of consumer perception in beach management?', especially in the UK, as can be seen in Wales through the Green Seas Initiative in which Welsh Water pic. are engaged. This research indicates that most people have little understanding of seaside award flags, if any at all. Reform to the EEC Directive concerning the quality of bathing water should attempt establishing an acceptable degree of risk to beach users and base the water quality determinands on sound scientific evidence. Finally, if agencies involved in utilising seaside award schemes as promotional tools wish to continue along this line, a strategy incorporating an intensive educational and marketing programme should be considered and account of reforms to water quality legislation should be strictly adhered.

Water Pollution 183

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