title: The association of drinking water treatment and distribution network disturbances with Health Call Centre contacts for gastrointestinal illness symptoms.
abstract: There are relatively few studies on the association between disturbances in drinking water services and symptoms of gastrointestinal (GI) illness. Health Call Centres data concerning GI illness may be a useful source of information. This study investigates if there is an increased frequency of contacts with the Health Call Centre (HCC) concerning gastrointestinal symptoms at times when there is a risk of impaired water quality due to disturbances at water works or the distribution network. The study was conducted in Gothenburg, a Swedish city with 0.5 million inhabitants with a surface water source of drinking water and two water works. All HCC contacts due to GI symptoms (diarrhoea, vomiting or abdominal pain) were recorded for a three-year period, including also sex, age, and geocoded location of residence. The number of contacts with the HCC in the affected geographical areas were recorded during eight periods of disturbances in the water works (e.g. short stops of chlorine dosing), six periods of large disturbances in the distribution network (e.g. pumping station failure or pipe breaks with major consequences), and 818 pipe break and leak repairs over a three-year period. For each period of disturbance the observed number of calls was compared with the number of calls during a control period without disturbances in the same geographical area. In total about 55, 000 calls to the HCC due to GI symptoms were recorded over the three-year period, 35 per 1000 inhabitants and year, but much higher (>200) for children <3 yrs of age. There was no statistically significant increase in calls due to GI illness during or after disturbances at the water works or in the distribution network. Our results indicate that GI symptoms due to disturbances in water works or the distribution network are rare. The number of serious failures was, however limited, and further studies are needed to be able to assess the risk of GI illness in such cases. The technique of using geocoded HCC data together with geocoded records of disturbances in the drinking water network was feasible.
authors.affiliation: Department of Sustainable Waste and Water, City of Gothenburg, Box 123, SE-424 23 Angered, Sweden. annika.malm@kretsloppochvatten.goteborg.se
authors.forename: Annika
authors.initials: A
authors.lastname: Malm
authors.forename: Gösta
authors.initials: G
authors.lastname: Axelsson
authors.forename: Lars
authors.initials: L
authors.lastname: Barregard
authors.forename: Jakob
authors.initials: J
authors.lastname: Ljungqvist
authors.forename: Bertil
authors.initials: B
authors.lastname: Forsberg
authors.forename: Olof
authors.initials: O
authors.lastname: Bergstedt
authors.forename: Thomas J R
authors.initials: TJ
authors.lastname: Pettersson
mesh_terms: D002675:Child, Preschool; D060766:Drinking Water; D005767:Gastrointestinal Diseases / Q000453:epidemiology*; D006296:Health Services / Q000706:statistics & numerical data*; D006801:Humans; D013548:Sweden / Q000453:epidemiology; D018508:Water Purification; D014881:Water Supply
chemical_list: D060766:Drinking Water
keywords: Distribution network; Drinking water quality; Gastrointestinal; Health Call Centres; Water works