آنالیز کیفی آب‌های ساحلی نوار جنوبی دریای خزر در استان گیلان و تعیین شاخص‌های بهداشت محیط در طرح‌های ساحلی آن منطقه

Background and purpose: Guilan province, with unique environmental values is located in southwest of the Caspian Sea. Disposal of untreated domestic, industrial and agricultural sewage to the surface of water pollutes the coastal waters of the Caspian Sea. Due to many pollutants in these swages they could endanger the health of swimmers. The purpose of this study was to evaluate the microbial contamination of water in the Caspian shores of Guilan province. Materials and methods: In this study 21 littoral swimming areas in Guilan were studied regarding microbial contamination by microbial indicators of fecal and total coliform with pH, temperature and turbidity during 2009-2010. In each swimming area six samples were taken during the study period. The data from the total of 122 samples were analyzed using statistical software. Results: The results showed that the mean of total coliform and fecal coliform was 234.8 and 60 MPN per 100 ml, respectively. The mean of total coliform in swimming areas 1 and 2 were 1445 and 600 MPN per 100 ml, respectively. Fecal coliform in swimming areas 1, 2, 6, 8, 9 and 10, was 195.3, 163.5, 131.5, 111.7, 127.8, 118.8 MPN per 100 ml, respectively. Significant correlation was found among temperature, turbidity, and microbial contamination (P<0.05). Conclusion: The results indicated that the mean of total coliform in two swimming areas and the mean of fecal coliform in six swimming areas were more than the standard level. Therefore, these swimming areas are considered as a microbial threat to swimmers.