Contamination Assessment and Zoning of Heavy Metals in Water and Sediment of Alagol Wetland, Iran 2017

Background and purpose: Heavy metal pollution is among the most serious environmental issues that is caused directly or indirectly through human activities or natural sources. Alagol wetland is one of the most important ecosystems in Iran which is affected by numerous agricultural and industrial development programs. Materials and methods: A descriptive cross-sectional study was performed in summer and autumn 2017. Heavy metal contamination (nickel, cadmium, and lead) was investigated in 50 samples from five different zones of water and sediment of wetland. Zoning was done using GIS and data analysis was performed applying ANOVA, Tukey’s test, and multivariate analysis (CA). Results: Average concentrations of cadmium, lead, and nickel in water were 0.013±0.02, 0.86±0.44, and 0.164±0.55 in summer and 0.021±0.03, 0.658±0.36, and 0.334±0.65 in autumn, respectively. The average concentrations of cadmium, lead, and nickel in sediment were 0.19±0.005, 2.103±0.011, and 0.489±0.102 in summer and 0.11±0.003, 1.796±0.261, and 0.353±0.2040 μg/kg dry weight in autumn, respectively. Conclusion: The level of contamination was found to be higher in western zone. The study showed high impact of human resources on lead and cadmium contents but nickel content was more of natural resources. The amount of metals measured were lower than the global standards. Industrialization, increasing rate of international road transportation, and agricultural activities caused high concentrations of metals in Alagol Wetland.