Professor Dearbháile Morris and Dr Liam Burke of NUI Galway say the EU-backed water pollution tests being used here do not give an accurate reading.
There has been an explosion of sea swimming in Ireland in recent times, and with that comes a demand for the best, up-to-date and detailed information about water quality. Some 73% of the 148 beaches and lakes which are formally designated as swimming spots are deemed to be of an excellent standard under EU testing rules. Overall, 96% meet the minimum standards.
But there is a deeper and more detailed way to analyse the level of pollution, which is not only more revealing but also more concerning. We, a group of researchers at NUI Galway Antimicrobial Resistance and Microbial Ecology (ARME) group have done just that. As well as that, in three pieces of research since 2017 we have reported the detection of antibiotic-resistant bacteria in swimming spots that are designated as of good or excellent quality.
This raises the question as to whether the EU sanctioned testing regime is good enough. The sampling and analysis for the Environmental Protection Agency’s Bathing Water Quality Report are based on the EU Water Framework Directive. Those regulations require local authorities to carry out sampling and testing at least once a month between 1 June and 15 September. They get two outputs – the most probable number of E. coli present and the most probable number of Intestinal Enterococci present. Based on the number of these in the sample, the waters are designated excellent, good, sufficient or poor.
We do not believe those quality standards are high enough. And here’s why. One part of the research carried out by ARME involved 30 litre samples being taken from 50 locations around Galway, Cork and Fingal, Dublin over several years. We ran the same tests as the local authority, with the same sample volume. But, we also ran the rest of our 30-litre samples through a special filter to catch any bacteria present. We then carried out molecular tests on extracted DNA in the search for a pathogenic form of E. coli called Shiga-toxigenic E.coli (STEC). The discovery is not a one-off, nor is it isolated. Shiga-toxigenic E.coli (STEC) is carried naturally by cattle and sheep but it is a risk to humans and a very small quantity has the potential to do us serious harm. If one of us was to ingest as few as 10 cells it could cause serious illness including bloody diarrhoea.
The research can be read in full on our website and people can also share what they feel are the barriers they see to using our seas, rivers and lakes and the reasons why they use these Blue Spaces.
Findings from other research are to be published in next month’s Environment International. It reveals an analysis of 39 water samples collected between November 2018 and July 2019 – 23 from the sea; five from rivers; four from estuaries; and three from lakes. All of the freshwater samples, and 83% of seawater samples, met the excellent classification standard for the number of E. coli when we tested them according to the bathing water monitoring criteria.
These superbugs are resistant to multiple second-line antibiotics, normally used to treat infections when the first line antibiotics fail. In five water samples, we even found CPE – the most worrying type of superbugs. These are resistant to even the last-resort antibiotics, the carbapenems.
Superbugs can get from a colonised person’s gut into other parts of the body such as the blood or urinary tract and cause infection. They can also potentially transfer from someone who is colonised to their close contacts, and this is a worry if they are vulnerable.
Effects on humans
The PIER project is looking into whether swimmers and surfers are more likely to be colonised with these superbugs than those who do not get into the water much. In order to build a picture of this issue, we need the public, particularly those who do not swim regularly, to support the research at www.nuigalway.ie/pier. It is the equivalent of 78,000 people flushing their toilets straight into natural waterways. In 2019, Ireland ranked 22nd out of 30 European countries for the quality of our bathing waters. It is also thanks to the EPA that a closer eye is being cast over the E.coli or Enterococci that exists in our waters and the characteristics of those organisms.
Our research group has revealed important detail about the quality of our seas, rivers and lakes, but it has also raised important issues over the EU standards we are asked to apply.
The Covid-19 pandemic and the restrictions imposed on society are undoubtedly part of the reason why there has been such interest and upsurge in outdoor swimming – both for the physical and mental health benefits. An EPA sponsored survey suggested that 65% of respondents believed that their “Blue Spaces” were of a high enough quality to spend time in.
We need to look for the characteristics of E. coli and not just the total amount of E. coli. We need to test our waters throughout the year and not just from June to September. Our research findings and the EPA’s current call for research proposals on the understanding of STEC in our waters are vital to informing policy at a national and European level.
Source – journal.ie