Impact of human activities on the rate of microbial contamination of the Gorgan Ziarat River, Iran

摘要

Monitoring the microbial quality of water resources is essential to measure their contamination. The present study is designed to assess the water quality of Ziarat River in the city of Gorgan regarding the microbiological parameters and impact of human intervention on itscontamination. In the present study, 60 water samples were taken from five sampling stations along about 20 km of the river from June to November 2015 and, then, investigated in terms of the bacteria of Salmonella, Shigella, Escherichia coli, Klebsiella, Enterobacter and Citrobacter according to the standard methods (APHA). Results of the current study revealed that at least one of the microbiological parameters was detected in more than 76.2% of the samples, among which the highest number was relatedto Citrobacter, Klebsiella, Enterobacter, Shigella, Salmonella and E. coli, respectively. The human intervention had the highest impact on the contamination rate, so that; the maximum and minimum loads of microbial contamination wereseen in the regions with residential-touristic usage and rural farming regions, respectively. The presence of the microbial agents in the samples confirmed that the water of Ziarat River could not be directly used for residential and recreational consumptions without treatment or disinfection processes. Thus, it is necessary to design and implement a river water protection programs to improve the water quality and prevent of water-borne diseases.