title: Applying QMRA and DALY to assess health risks from river bathing.
abstract: To estimate the health impact of bathing in urban river waters a two-step risk assessment was conducted using the example of the Ruhr River in North-Rhine Westphalia (Germany). The risk of acquiring gastrointestinal illness (GI) due to bathing in the Ruhr River was the focus of this analysis. Referring to the WHO guidelines for safe recreational water environments, risk was defined as the probability of occurrence x severity of harm. Thus, the probability of acquiring GI by bathing in the Ruhr River has been calculated by means of the quantitative microbial risk assessment (QMRA) method. Additionally to this, harm was operationalized by using the DALY metric, quantifying the impact of disability for public health. The calculation of the DALYs based on the QMRA results, disease and lethality data of the population, duration of diseases, disability weights and a demographic profile of a regionally determined potential bathing population. DALYs were calculated for norovirus gastroenteritis, rotavirus gastroenteritis, cryptosporidiosis and giardiasis. The calculated DALYs were set into relation to other risks of daily life. Furthermore the effect of age weighting and time discounting for this site-specific population was considered. The viral load caused the main part of the environmental burden of disease by bathing in the river. The calculated DALYs are significantly lower than DALYs for all cause GI in Germany, which reach 1.19 DALY/1000, or DALYs accepted for an official EG designated bathing water (2.579 DALYs/1000 persons) but on a comparable level with the DALY for drowning (0.26 DALY/1000 Persons). The DALY concept provides a complementary tool to the QMRA for evaluating and comparing health risks arising from a specific environment for a specific population and behaviour and for comparing with other health risks of daily life.
authors: IHPH-Institute for Hygiene and Public Health, GeoHealth Centre, University of Bonn, 53105 Bonn, Germany. Electronic address: Christian.Timm@ukb.uni-bonn.de.
authors: Christian
authors: C
authors: Timm
authors: IHPH-Institute for Hygiene and Public Health, GeoHealth Centre, University of Bonn, 53105 Bonn, Germany.
authors: Stephan
authors: S
authors: Luther
authors: Department for Hygiene, Social and Environmental Medicine, Ruhr-University Bochum, 44801 Bochum, Germany.
authors: Lars
authors: L
authors: Jurzik
authors: Environmental Virology Laboratory, Department of Water Pollution Research, National Research Centre, Dokki, Cairo, Egypt.
authors: Ibrahim Ahmed
authors: IA
authors: Hamza
authors: IHPH-Institute for Hygiene and Public Health, GeoHealth Centre, University of Bonn, 53105 Bonn, Germany.
authors: Thomas
authors: T
authors: Kistemann
mesh_terms: D000293:Adolescent; D000328:Adult; D002167:Campylobacter / Q000302:isolation & purification; D003457:Cryptosporidiosis / Q000453:epidemiology; D003458:Cryptosporidium / Q000302:isolation & purification; D004784:Environmental Monitoring; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology; D005858:Germany / Q000453:epidemiology; D005872:Giardia / Q000302:isolation & purification; D005873:Giardiasis / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D029322:Norovirus / Q000302:isolation & purification; D019057:Quality-Adjusted Life Years; D011998:Recreation; D018570:Risk Assessment; D045483:Rivers / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D012475:Salmonella / Q000302:isolation & purification; D014871:Water Microbiology; D014873:Water Pollutants / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D014873:Water Pollutants
keywords: Disability adjusted life years (DALY); Infectious diseases; Quantitative microbial risk assessment (QMRA); Recreational water; Risk assessment