Assessment of fecal contamination and its potential risks of rainwater collected in Hanoi city, Vietnam

Le Nhu Da; Phung Thi Xuan Binh; Nguyen Thi Mai Huong; Hoang Thi Thu Ha; Nguyen Thi Anh Huong; Pham Thi Minh Hanh; Duong Thi Thuy; Le Thi Phuong Quynh

doi:10.15625/2615-9783/23607

Author affiliations

Authors

Nhu Da Le 1-Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam; 2-Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
Thi Xuan Binh Phung Electric Power University, Hanoi, Vietnam
Thi Mai Huong Nguyen Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam
Thi Thu Ha Hoang 1-Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam; 2-Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
Thi Anh Huong Nguyen Faculty of Chemistry, University of Science, Vietnam National University-Hanoi, Hanoi, Vietnam
Thi Minh Hanh Pham Institute of Mechanics, Vietnam Academy of Science and Technology, Hanoi, Vietnam
Thi Thuy Duong Institute of Science and Technology for Energy and Environment, Vietnam Academy of Science and Technology, Hanoi, Vietnam
Thi Phuong Quynh Le 1-Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam; 2-Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam

DOI:

https://doi.org/10.15625/2615-9783/23607

Keywords:

Fecal indicator bacteria, Escherichia coli, rainwater, potential risk assessment, urban areas, Hanoi, wet deposition

Abstract

Fecal indicator bacteria (FIB) are used worldwide as indicators of fecal contamination in water, particularly in drinking water. This paper aims to investigate the level of FIB contamination and its associated public health risks in rainwater samples collected at 22 sites in inner-urban and suburban districts of Hanoi City during the period from May 2023 to May 2025. The results showed higher FIB values in inner-urban districts where high population densities were reported. The mean values of TC and EC in raw rainwater at most sites observed were higher than the limits of the Vietnam national technical regulation for domestic water use and also the WHO (2022) guideline for drinking water. A high public health risk was identified, and rainwater was unsuitable for direct potable use without treatment. Thus, our results underscore the importance of preventive and treatment measures to mitigate the risks associated with using harvested rainwater. Both natural and anthropogenic factors are primarily influencing the spread and persistence of FIB in this study. Our results provide a scientific basis for policy-making in air environmental protection for Hanoi City, as well as other large cities in developing countries in Asia.

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