Sea swimming could lead to ailments, study finds

Is it safe to go back into the water?


A comprehensive research done by the University of Exeter Medical School in collaboration with the Centre for Ecology and Hydrology demonstrated that sea bathing doubled the odds of reporting general ear ailments, and the odds of reporting earache in particular increased by 77%. For gastrointestinal illnesses, the odds increased by 29%.

It is the first systematic review to investigate the evidence on spending time in the sea makes people more likely to develop a variety of ailments than people who do not.

Dr. Anne Leonard, of the University of Exeter Medical School, said, “In high-income countries like the UK, there is a perception that there is little risk to the health of spending time in the sea. However, our paper shows that spending time in the sea does increase the probability of developing illnesses, such as ear ailments and problems involving the digestive system, such as stomach ache and diarrhoea. We think that this indicates that pollution is still an issue affecting swimmers in some of the world’s richest countries.”

Nevertheless, exceptional investment resulting in an improved water quality in recent years, seawater is still polluted from sources comprising industrial waste, sewage, and run-off from farmland.

Scientists pare down more than 6,000 studies to 19 studies which met the strict criteria for inclusion in the meta-analysis, designed to establish substantial research evidence. Many of the studies comprised recruited thousands of participants. The number of people analyzed in total exceeded 120,000.

All the studies were conducted in high-income countries since 1961. The studies looked at the links between sea bathing and the incidence of illness in countries including the US, UK, Australia, New Zealand, Denmark, and Norway.

Dr. Will Gaze, of the University of Exeter Medical School, supervised the research, said, “We don’t want to deter people from going into the sea, which has many health benefits such as improving physical fitness, wellbeing and connecting with nature. However, it is important that people are aware of the risks so they can make informed decisions. Although most people will recover from infections with no medical treatment, they can prove more serious for vulnerable people, such as the very old or very young, or those with pre-existing health conditions. We have come a long way in terms of cleaning up our waters, but our evidence shows there is still work to be done. We hope this research will contribute to further efforts to clean up our coastal waters.”

Dr. Ruth Garside, of the University of Exeter Medical School, is an expert on systematic reviews, said, “Systematic reviews use rigorous methods to identify and assess all the relevant research on a topic in an unbiased way. The study findings are then combined statistically – this allows us to have more confidence in the results.”

The paper is published in the International Journal of Epidemiology.

Authors are Anne Leonard, Andrew Singer, Obioha Ukoumunne, William Gaze, and Ruth Garside.

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