A new study has found bathing in the sea increases the risk of ear infections, and gastrointestinal illnesses that cause diarrhoea.
A major review of 40 previous studies found the risk of picking up stomach aches or diarrhoea increased by 29 per cent for bathers, compared to those who had not recently been swimming in the sea.
The likelihood of reporting an earache increased by 77 per cent after a swim, according to the research published on Monday in the International Journal of Epidemiology.
Most of the studies entailed talking to people at beaches and near the seaside.
The academics behind the study said they hope the work leads to a push to clean up coastal waters. The research was undertaken by the University of Exeter Medical School and the UK-based Centre for Ecology and Hydrology.
Dr Anne Leonard, an academic at the University of Exeter Medical School, said there was a “perception” in high-income countries that there was no health risks to spending time in the sea, but their research pointed in the opposite direction.
The study suggested that “pollution is still an issue affecting swimmers in some of the world’s richest countries”, she said.
The research looked at previous studies carried out in several countries since the 1960s, including the United Kingdom, Australia, the United States, Denmark and Norway.
The academics read over 6,000 different studies before picking 40 papers that looked at links between swimming and the risk of picking up illnesses.
Stomach aches
Out of the 40 studies, 21 found a link between bathing and ear infections, and 28 indicated a higher risk of stomach aches or diarrhoea, caused by gastrointestinal illness.
The study found little difference between those who put their heads under water and those who did not in terms of the likelihood of picking up an illness
The research, which is the first of its kind in drawing together a review of past studies on health risks to bathers, was financed by the European Regional Development Fund.
Dr Will Gaze, another coauthor from the University of Exeter Medical School, said they “don’t want to deter people from going into the sea,” which itself has health benefits.
But he added it was “important that people are aware of the risks so they can make informed decisions”.
The type of illnesses picked up from swimming were relatively easy for most people to recover from without medical treatment but might be more serious for the elderly or very young children, or people with underlying 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 Gaze said.
