By investigating health risks associated with bathing waters, scientists are contributing to future reviews and revision of the EU's Bathing Water Directive.
Europe's bathing water has come a long way in the last few decades. Especially since the EU Bathing Water Directive in 1976, countries have worked to eliminate sewage contamination in the waters we swim or paddle in. David Kay, water quality expert and head of the Centre for Research into Environment and Health at Aberystwyth University in Wales, UK, has studied the disease causing organisms in European waters since the 1970s. More recently, he also helped to quantify their health effects on people. Here, he tells youris.com about progress in bathing water qualities over the past four decades.
What kind of harmful diseases can lurk in our bathing waters?
You can get some fairly common, but minor ailments like gastroenteritis and winter vomiting bug [also known as norovirus]. These virus infections are generally not life threatening. But they could have economic significance and be an uncomfortable experience for holidaymakers. There are quite high attack rates caused by bathing in water polluted by sewage.
What has been the impact of the Epibathe research project in Europe?
We performed the first clinical trial focused on assessing the quality of bathing waters in Europe. A repeat of this approach in the EU funded Epibathe project, completed in 2008, confirmed the position of the first WHO guidelines for recreational water, published in 2003. The latter were included in the 2006 EU Bathing Water Directive.
The original Bathing Water Directive in 1976 was the first environmental directive in Europe and the aim was simple: to protect public health. But there was no basic epidemiology to underpin this directive with solid evidence. The project was about filling in the gaps with epidemiological evidence on a wider range of EU waters such as Mediterranean and river bathing waters in Hungary. It compared volunteer bathers and non-bathers in a randomised controlled trial, the gold standard for scientific trials.
Has bathing water quality improved over the last decade or more?
There has been a dramatic improvement. When bathing water directive first came in 1976, the most common disposal practice was to dump sewage into the sea untreated. Even if you disposed of it far from shore, it could come back to bathing waters. The first directive started the cleanup process, even though it did not have a good evidence base in terms of the science. Since then billions of euro have been spent on sewage treatment facilities and more beaches are passing directive standards.
A 2012 Bathing Water Report said 94% complied with minimum standards. What does this mean?
We are still applying 1976 bathing water directive standards. A beach can pass what's called the imperative level, which is the minimum standard. But there is also a guide value, which is the recommended standard. Our work within the Epibathe project has shown that there is a significant health risk at the imperative standard, but you dramatically reduce risk once you go to the guide standard.