Quantitative Microbial Risk Assessment for Recreational Exposure to Water Bodies in Philadelphia

Abstract

A quantitative microbial risk assessment was conducted to estimate risk of gastrointestinal (GI) illnesses associated with recreational exposure to Philadelphia waterways, under dry and wet weather conditions. Using maximum likelihood estimation, stochastic exposure models were generated for each exposure scenario and Monte Carlo techniques were applied to characterize uncertainty in final risk estimates. The dry-weather risk estimates were found significantly lower than those predicted for wet-weather conditions. Moreover, the predicted risk, calculated in proportion of the frequency of use, was elevated at 6 out of 10 sites (ranging from 9 to 52 illnesses/1000 users/ day). Activities contributing most to the risk of GI illness at creeks were identified as wading and playing (81%), while fishing was the potential risk contributor (65%) at rivers. The quantitative measure of risk contribution from each type of water activity obtained from this study can be useful for policy makers in prioritizing the future interventions.

Evaluating Nahoon Beach and Canal Waters in Eastern Cape, South Africa: A Public Health Concern

“…For E. coli, a beta-Poisson dose-response model was used to calculate the probability of infection (Pi) resulting from the incidental ingestion of 0.1 ml, 1 ml, 10 ml, and 100 ml of beach water as described by the World Health Organization [22]. The 1 ml value for incidental ingestion was defined as the volume (droplets resulting from splashing) of water accidentally swallowed through the mouth or inhaled through the nose and subsequently swallowed [23]. Since E. coli isolated from environmental samples could include non-pathogenic strains, the Pi was calculated based on the assumption that 8% of average E. coli counts are pathogenic [24].…”

Exploratory Assessment of Risks from Drinking and Recreational Water Exposure to Children in the State of New Jersey

“…However, for swimming, the United States Environmental Protection Agency (EPA) default exposure duration for children less than 6 years of age was considered [41]. Water ingestion rates accounted for fixed and incidental ingestion of water, where fixed intake refers to inhalation of mist and droplets via mouth and nose [42]. Using default ingestion rates and summing the results from each activity, as outlined in Table 3, it was found that children may incidentally ingest 0.078 liters of river water per day during a full day of recreation.…”

The severely under‐recognized public health risk of strongyloidiasis in North American cities—A One Health approach

“…Behaviours involving potential contact with sediment/mud in urban areas (e.g. swimming, wading, bathing/washing, fishing, walking barefoot, fishing, picnicking and collecting trash along shorelines) can potentially result in infection and have been documented in or near urban waterways (Donovan, Unice, Roberts, Harris, & Finley, ; Sunger & Haas, ; Sunger, Teske, Nappier, & Haas, ). We also note that the Baermann technique, which is used to diagnose Strongyloides , involves suspending faecal matter in cloth (“coarse fabric”) and analysing larvae that have migrated through that cloth (Siddiqui & Berk, ).…”

“…Behaviours involving potential contact with sediment/ mud in urban areas (e.g. swimming, wading, bathing/washing, fishing, walking barefoot, fishing, picnicking and collecting trash along shorelines) can potentially result in infection and have been documented in or near urban waterways (Donovan, Unice, Roberts, Harris, & Finley, 2008;Sunger & Haas, 2015;Sunger, Teske, Nappier, & Haas, 2012).…”