Numerous bacterial genetic markers are available for the molecular detection of human sources of fecal pollution in environmental waters. However, widespread application is hindered by a lack of knowledge regarding geographical stability, limiting implementation to a small number of well-characterized regions. This study investigates the geographic distribution of five human-associated genetic markers (HF183/BFDrev, HF183/BacR287, BacHum-UCD, BacH, and Lachno2) in municipal wastewaters (raw and treated) from 29 urban and rural wastewater treatment plants (750 – 4,400,000 population equivalents) from 13 countries spanning six continents. In addition, genetic markers were tested against 280 human and non-human fecal samples from domesticated, agricultural and wild animal sources. Findings revealed that all genetic markers are present in consistently high concentrations in raw (median log10 7.2 - 8.0 marker equivalents (ME) 100 ml-1) and biologically treated wastewater samples (median log10 4.6 - 6.0 ME 100 ml-1) regardless of location and population. The false positive rates of the various markers in non-human fecal samples ranged from 5% to 47%. Results suggest that several genetic markers have considerable potential for measuring human-associated contamination in polluted environmental waters. This will be helpful in water quality management and pollution modeling and health risk assessment across the globe (as demonstrated by QMRAcatch).
- School of Environment and Technology - Professor of Environmental Microbiology
- Centre for Aquatic Environments
- Centre for Spatial, Environmental and Cultural Politics
- Environment and Public Health Research and Enterprise Group