A cross-sectional study on the prevalence of illness in coastal bathers compared to non-bathers in England and Wales: Findings from the Beach User Health Survey

The risks of illness associated with bathing in UK coastal waters have not been quantified since the early 1990s. Efforts have been made since then to improve the quality of bathing waters. The aim of this study was to quantify the prevalence of symptoms of illness associated with sea bathing in bathers in England and Wales. A cross-sectional study was conducted between June 2014 and April 2015. An online survey collected information from sea bathers and non-bathers on their visits to beaches in England and Wales along with the occurrence of symptoms of illness. 2631 people (1693 bathers, 938 non-bathers) responded to the survey. Compared to non-bathers, bathers were more likely to report skin ailments (adjusted prevalence odds ratio (AOR) = 2.64, 95% confidence interval (CI) 1.23 to 5.65, p = 0.01), ear ailments (AOR = 3.77, 95% CI 1.84 to 7.73, p < 0.001), and any symptoms of illness (AOR = 3.73, 95% CI 2.63 to 5.29, p < 0.001). There was weak evidence of an increase in the odds of gastrointestinal illness (AOR = 1.59, 95% CI 0.96 to 2.65, p = 0.07), respiratory ailments (AOR = 2.44, 95% CI 0.92 to 6.48, p = 0.07) and eye ailments (AOR = 2.12, 95% CI 0.83 to 5.39, p = 0.11). While the study design does not allow inference of causality, we do observe an association between sea bathing in England and Wales and reported symptoms of ill health. This suggests that despite higher rates of compliance with water quality criteria among bathing waters nowadays, the odds of illness for bathers relative to non-bathers is similar in magnitude to estimates made in the 1990s.