Tracking faecal microorganisms using the qPCR method in a typical urban catchment in China

Area of Science:

• Environmental microbiology
• Urban hydrology
• Public health

Background:

• Faecal microorganisms in urban runoff pose significant risks to human health.
• Identifying sources of microbial contamination is crucial for effective water management.

Purpose of the Study:

• To evaluate the origins of faecal microbial contamination in urban stormwater runoff.
• To determine the relative contributions of different animal and human sources to pollution.

Main Methods:

• Quantitative polymerase chain reaction (qPCR) to detect Bacteroidetes as an indicator organism.
• Principal component analysis (PCA) to analyze environmental factors influencing pollution.

Main Results:

• Dog waste was identified as the largest contributor to faecal pollution in stormwater runoff, followed by bird and human sources.
• Human and dog pollutants exhibited a 'first flush' effect, while bird pollutant transmission was longer.
• Antecedent drying days were a key factor for dog faecal pollution; human pollution was influenced by multiple factors.

Conclusions:

• Understanding the sources and transport of faecal pollution is essential for urban water management.
• This research provides evidence for targeted strategies to mitigate nonpoint source faecal pollution in urban catchments.