Susceptibility of a peri-urban water supply and sanitation system to selected emerging micropollutants.

As cities expand and human activity increases, peri-urban areas – regions on the outskirts of cities – are developing rapidly. This affects water quality including pollutants and antibiotic resistant bacteria and genes. While urban water systems have been studied extensively, peri-urban water systems are less understood. Researchers tested water and sewage quality at seven locations in a peri-urban area serving over 2,500 people during spring and winter. The research results showed that microplastics were not present in samples of raw or tap water, or in treated sewage. However, microplastics were found in raw sewage, raising environmental and health concerns. Antibiotic resistance genes were present in most samples except for drinking water from the supply network though it still contained some microorganisms. After sewage was discharged into a river antibiotic resistance gene levels increased by about 50%. The most common resistance genes in raw sewage were tetA and blaTEM. Wastewater treatment effectively removed over 90% of integrase genes in both seasons helping to reduce the spread of resistance. These results show the need for more research to understand and address water contamination risks in peri-urban areas.