Sarker Shishir K, Dapkus Ryan T, Byrne Diana M, Fryar Alan E, Hutchison Justin M
Department of Earth and Environmental Sciences, University of Kentucky, Lexington, KY 40506, USA.
Department of Civil Engineering, University of Kentucky, Lexington, KY 40506, USA.
Water (Basel). 2025 Mar;17(5). doi: 10.3390/w17050745. Epub 2025 Mar 4.
Karst aquifers can be highly productive water sources but are vulnerable to contamination by pathogens because of integrated surface and subsurface drainage. Our study focuses on the karstic Royal Spring basin in Kentucky, encompassing urban and agricultural land uses. The city of Georgetown distributes treated water from Royal Spring to over 33,000 customers. We examined dynamics at Royal Spring from June 2021 through June 2022, assessing variability under wet versus dry weather conditions. We also used quantitative microbial risk assessment (QMRA) to estimate potential health risks from the pathogenic bacterium O157:H7. concentrations in weekly water samples varied from 12 to 1732.8 MPN/100 mL, with a geometric mean of 117.2 MPN/100 mL. The mean concentration in wet periods was approximately double that during dry conditions. Because the pathogen was not detected by quantitative PCR (qPCR), we conducted QMRA based on literature data for water treatment plant operations (occupational) and recreational activities near the spring. The median probability of annual infection was 5.11 × 10 for occupational exposure and 1.45 × 10 for recreational exposure. Uncertainty and sensitivity analyses revealed that health risks were most sensitive to the pathogen/ ratio and ingestion rate. Although the pathogen was not detected by qPCR, the presence of suggests potential fecal contamination. This highlights the importance of continued monitoring and investigation of different detection methods to better understand potential health risks in karst systems.
岩溶泉含水层可能是高产的水源，但由于地表水和地下水排水系统相互连通，容易受到病原体污染。我们的研究聚焦于肯塔基州的岩溶皇家泉流域，该流域涵盖了城市和农业用地。乔治敦市将皇家泉处理后的水供应给超过33000名用户。我们在2021年6月至2022年6月期间对皇家泉的动态进行了研究，评估了潮湿和干燥天气条件下的变化情况。我们还使用了定量微生物风险评估（QMRA）来估计致病性细菌O157:H7的潜在健康风险。每周水样中的浓度在12至1732.8 MPN/100 mL之间变化，几何平均值为117.2 MPN/100 mL。潮湿时期的平均浓度约为干燥条件下的两倍。由于定量聚合酶链反应（qPCR）未检测到病原体，我们基于水处理厂运营（职业）和泉水附近娱乐活动的文献数据进行了QMRA。职业暴露的年度感染中位概率为5.11×10，娱乐暴露为1.45×10。不确定性和敏感性分析表明，健康风险对病原体/比例和摄入率最为敏感。尽管qPCR未检测到病原体，但 的存在表明存在潜在的粪便污染。这凸显了持续监测和研究不同检测方法以更好地了解岩溶系统中潜在健康风险的重要性。
