title: Bather density as a predominant factor for health effects related to recreational bathing: results from the Greek bathers cohort study.
abstract: Our aim was to examine the health effects on bathers from exposure to recreational seawater on three beaches with different microbiology quality and bather density through a cohort study. An initial questionnaire and a 10 day follow up were used. Univariate and backward logistic regression analyses were used to asses the risk of developing symptoms or diseases among the bathers. In total, 3805 bathers were included in the study and 149 samples were collected from the three beaches. Despite all the beaches being characterized of high quality the levels of bacterial indicators differed among them. Health effects among bathers were not associated with bacterial indicators. A statistically significant increased risk for symptoms related to respiratory illness, gastroenteritis, medical consultation and use of medication was observed among bathers at the higher bather density beaches. Beach bather numbers should always be taken into account when considering a risk assessment approach.
authors.affiliation: Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 22 Papakyriazi Str., Larissa 41222, Greece. panpapast@med.uth.gr
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Papastergiou
authors.forename: Varvara A
authors.initials: VA
authors.lastname: Mouchtouri
authors.forename: George
authors.initials: G
authors.lastname: Rachiotis
authors.forename: Ourania
authors.initials: O
authors.lastname: Pinaka
authors.forename: Anna
authors.initials: A
authors.lastname: Katsiaflaka
authors.forename: Christos
authors.initials: C
authors.lastname: Hadjichristodoulou
mesh_terms: D001493:Bathing Beaches / Q000706:statistics & numerical data*; D015331:Cohort Studies; D004427:Ear Diseases / Q000453:epidemiology / Q000382:microbiology; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D005128:Eye Diseases / Q000453:epidemiology / Q000382:microbiology; D005759:Gastroenteritis / Q000453:epidemiology / Q000382:microbiology; D006115:Greece; D006801:Humans; D016015:Logistic Models; D011156:Population Density; D012044:Regression Analysis; D012140:Respiratory Tract Diseases / Q000453:epidemiology / Q000382:microbiology; D018570:Risk Assessment; D012623:Seawater / Q000382:microbiology*; D011795:Surveys and Questionnaires; D013550:Swimming / Q000706:statistics & numerical data*