title: Quantitative microbial risk assessment of human illness from exposure to marine beach sand.
abstract: Currently no U.S. federal guideline is available for assessing risk of illness from sand at recreational sites. The objectives of this study were to compute a reference level guideline for pathogens in beach sand and to compare these reference levels with measurements from a beach impacted by nonpoint sources of contamination. Reference levels were computed using quantitative microbial risk assessment (QMRA) coupled with Monte Carlo simulations. In order to reach an equivalent level of risk of illness as set by the U.S. EPA for marine water exposure (1.9 × 10(-2)), levels would need to be at least about 10 oocysts/g (about 1 oocyst/g for a pica child) for Cryptosporidium, about 5 MPN/g (about 1 MPN/g for pica) for enterovirus, and less than 10(6) CFU/g for S. aureus. Pathogen levels measured in sand at a nonpoint source recreational beach were lower than the reference levels. More research is needed in evaluating risk from yeast and helminth exposures as well as in identifying acceptable levels of risk for skin infections associated with sand exposures.
authors.affiliation: Institute for the Study of the Environment, Sustainability, & Energy and School of Nursing & Health Studies, Northern Illinois University, DeKalb, Illinois, United States. tshibata@niu.edu
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shibata
authors.forename: Helena M
authors.initials: HM
authors.lastname: Solo-Gabriele
mesh_terms: D001493:Bathing Beaches / Q000592:standards*; D002140:California; D002648:Child; D003198:Computer Simulation; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D007239:Infections / Q000382:microbiology* / Q000469:parasitology*; D009010:Monte Carlo Method; D012015:Reference Standards; D018570:Risk Assessment; D012307:Risk Factors; D012623:Seawater / Q000382:microbiology*; D012822:Silicon Dioxide; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D012822:Silicon Dioxide