Urbanization Impacts the Physicochemical Characteristics and Abundance of Fecal Markers and Bacterial Pathogens in Surface Water

Abstract

Urbanization is increasing worldwide and is happening at a rapid rate in China in line with economic development. Urbanization can lead to major changes in freshwater environments through multiple chemical and microbial contaminants. We assessed the impact of urbanization on physicochemical characteristics and microbial loading in canals in Suzhou, a city that has experienced rapid urbanization in recent decades. Nine sampling locations covering three urban intensity classes (high, medium and low) in Suzhou were selected for field studies and three locations in Huangshan (natural reserve) were included as pristine control locations. Water samples were collected for physicochemical, microbiological and molecular analyses. Compared to medium and low urbanization sites, there were statistically significant higher levels of nutrients and total and thermotolerant coliforms (or fecal coliforms) in highly urbanized locations. The effect of urbanization was also apparent in the abundances of human-associated fecal markers and bacterial pathogens in water samples from highly urbanized locations. These results correlated well with land use types and anthropogenic activities at the sampling sites. The overall results indicate that urbanization negatively impacts water quality, providing high levels of nutrients and a microbial load that includes fecal markers and pathogens.

Watershed land use, surface water vulnerability and public health risks of two urban rivers, Ado-Ekiti, South-West Nigeria

“…Emphasis has also been made on the positive association between urbanization intensity and incidence of multiple nutrients (total nitrogen and total phosphorus) and indicator bacteria (thermotolerant coliforms) [16] in adjacent surface water. Since high-density urban areas are marked by highly populated residential settlements [108], it is expected that watersheds with a greater percentage of built-up land use will record greater microbial presence in surface water due to increased domestic wastewater or sewage runoff. This corroborates findings from this study where the rivers with more builtup areas (i.e., Awedele river) within its watershed showed greater deterioration of surface water quality.…”

Fecal Contamination and High Nutrient Levels Pollute the Watersheds of Wujiang, China

“…In the current study, we have successfully performed assays for four MST markers, targeting universal (BacUni) [21], human-associated (HF183 Taq) [18], avian associated (AV4143) [20], and swine-associated (Pig-2-Bac) Bacteroidales [19] markers. Both BacUni and HF183 Taq fecal markers were detected in high numbers at all sampling locations in rivers and lake, indicating that fecal contamination was high at all sampling locations investigated ( Figure 6).…”

“…The total coliforms (TC) and fecal coliforms (FC) or thermotolerant coliforms counts were determined to assess the microbiological quality of the water as reported in our previous studies [6,19]. In brief, 100 µL samples of serially diluted water samples were plated on Harlequin TM E. coli/coliform medium (LabM, Heywood, UK) [20], and the plates were incubated at 37 °C for 24 h. The E. coli and coliforms were counted to determine the average number of total colonies forming units (cfu) per mL of water.…”

Literature Review: Water Quality of Public Bathing, Potential Health Problems and Water Borne Diseases on Visitors

“…Feces that pollute the water is a problem that requires serious attention due to their negative impact on aquatic ecosystems and human health. Examining fecalpolluted water can be done by assessing the presence of Thermotolerant coliform (TTC) and Enterococcus in the water (33). Besides, coliform group (total coliform, fecal coliforms, E. coli) and Streptococci (enterococci and fecal streptococci) can also be indicators key of fecal contamination (5).…”