It is common to read media reports of the risks associated with swimming, surfing, kayaking and generally playing in waters which are polluted. Diseases such as gastrointestinal illnesses and ear and eye infections are linked to swimming in coastal waters and are estimated to cost the global economy around $12 billion (Shuval, 2003).

While this sounds shocking, the reality for most of the UK is that the positive health benefits for users of coastal waters far outweigh the risks of illness. These health benefits include: The physiological and psychological benefits of exercise; physical and psychological restorative-ness and calming (Straughan, 2012; Phillips et al., 2018); alleviation of symptoms of chronic conditions such as depression (Denton, 2017). Unfortunately, it is incredibly difficult to directly compare the risks and benefits of using coastal waters. This means that it is difficult:

  • For humans to know when they should or should not use a bathing water.
  • For local authorities and water companies to know how much should be spent to improve bathing water quality.
Photo by Šárka Jonášová

As humans, we are terrible at subjectively comparing the risks and benefits of any activity and so need a little help from time to time. To help us humans decide if it is safe to swim at a beach, the Environment Agency test the water quality at 413 beaches in England, designated as “Bathing Waters”, once per week between May and Sept. Bathing Waters are classified as either: Excellent; Good, Sufficient or Poor, which relate to the risk to public health. So if a beach has “Excellent” water quality, you stand very little chance of becoming ill from swimming at that beach. This information is available online or on signs at every bathing water in the UK.  The quality of bathing waters can decrease quickly, however, during heavy-rainfall which causes pollution to enter the sea as poo from livestock or fertilizer is wash from fields, or sewers overflow (They are designed to do this to prevent homes flooding with sewage). This decrease in water quality usually lasts less than 24 hours and so are referred to as short-term pollution events. These short-term pollution events are important as they represent times when the risks of using bathing waters may outweigh the benefits.

dscn1609.jpgTo keep water users safe during these events, the Environment Agency has become great at forecasting when short-term pollution events will occur. The Environment Agency contact local authorities so that they can warn the public through the use of signs at bathing waters. Sometimes these signs are put out by hand, while some local authorities use electronic signs to warn the public that water quality might be poor. This is suggested to help protect the health of beach visitors by persuading them to avoid bathing at these times. I am unconvinced that these signs are useful. If you went down to the beach to swim/surf/kayak etc. and saw a warning “Bathing Water Quality May be Impaired”, would you turn around and go home or accept the risk? Personally, I would probably accept the risk if I knew the area well, but I am probably more stubborn than most. From discussions at a recent conference, it became apparent that we have a poor understanding of whether or not the public pay attention to water quality signs; what type of information the public will pay attention to; and what the public understands by poor water quality.

Water companies and local authorities can try to estimate how much to invest in improving bathing waters by conducting surveys of local communities and businesses. One example is a willingness to pay survey which is conducted by water companies. These try to estimate how much extra customers are willing to pay on their water bill if there are improvements in say the quality of a river, for example. These are really difficult to get right and rely on customers trusting the business conducting the survey – would people be willing to give more to Water Aid than they would pay extra on their water bill?

This is why I got incredibly excited (Yes, excited. Don’t judge) to see a recent report (Phillips et al., 2018)which gives valuable insight into the value of bathing waters and how the public interacts with water quality information. This report shows some forward-thinking by the Scottish Government and is vital for policymakers across Europe. Sadly the report also risks being shelved away on an unnavigable government website so I wanted to highlight some of the insights here I thought were most important.


The study considered 5 different bathing waters in Scotland. On average a single beach visit was worth about £8.90 per person per visit to the local economy. Across the 5 sites in Scotland used in the study, beach visits were worth an estimated £12.7M per year. Imagine the worth of 413 bathing waters in England! Interestingly, if water quality was poor, when the public would be advised against bathing, between 5% and 29% of visitors would visit less often. So health benefits aside, there is some evidence that investing up to £2M/ year to improve or maintain the quality of local bathing water quality would not be wasted.

The report also highlights some important insights into how we interact with water quality information. The report notes that Almost three-quarters of respondents to an online questionnaire said that they:

“Hadn’t seen or don’t remember seeing any signs and, crucially, that they didn’t look for them.”

This is an important statistic. A lot of money has been spent putting signs up at 413 bathing waters in the UK and most people do not look for or pay attention to bathing water quality information signs! This could be because the information is perceived to be irrelevant, lacking detail or out-dated. This should be a big red flashing light for policymakers. Are signs the wrong method of delivering information or do they contain the wrong information? It seems that regular water users, like water sports enthusiasts, instead relied on other information sources such as social media and word-of-mouth to make their own judgements about the water quality. A quote from a swimming group member caught my attention:

 “So if there was a sign like that but [local swimmers] had told me it was okay and there were other swimmers there I’d probably just go in”.

Trusting local knowledge over signs may be instinctive. Signs are in place year-round so there is no guarantee that the information is up to date while interactions with other, like-minded people present opportunities to access local, individualised and up-to-date information. This highlights an interesting point. While local water users are not necessarily experts in water quality or public health their information is accessible. In contrast, signage presents signs contains advice from experts, which appears to be inaccessible to the majority of beach users. Wouldn’t it be great if anyone could access information from local and expert sources? Something for local authorities to ponder. One bit of good news for water quality signs was reports of tourists enquiring about the reasons for poor bathing water quality at local businesses. Perhaps these signs are more useful to occasional visitors rather than the regular beach and water users.

While collecting and interpreting survey data is incredibly difficult, this report highlights the importance of good water quality to local economies. And while the health benefits usually outweigh the risks of using coastal waters, it is really important that we get better at communicating when short-term pollution events increase the risk of illness for water users. So next time you are visiting a beach, don’t forget to check for water quality signs at the beach, or at least speak to a local.

If you would like to read the full report it is on the Scottish Gov website here.

Cover Photo by Todd Quackenbush



Denton, H. (2017) ‘Mental Wellbeing and Open water Swimming’, in UK Bathing Water Conference 2017. Available at:$RZh3O48!/~undefined.

Phillips, P. et al. (2018) The Value of Bathing Waters and the Influence of Bathing Water Quality: Final Research Report. Edinburgh. Available at:

Shuval, H. (2003) ‘Estimating the global burden of thalassogenic diseases: human infectious diseases caused by wastewater pollution of the marine environment.’, Journal of water and health. England, 1(2), pp. 53–64.

Straughan, E. R. (2012) ‘Touched by water: The body in scuba diving’, Emotion, Space and Society, 5(1), pp. 19–26. doi: 10.1016/j.emospa.2010.10.003.