1�ol.:ȋͬͭͮͯͰͱͲͳʹScientific Reports | (2022) 12:17455 | https://doi.org/10.1038/s41598-022-21752-wwww.nature.com/scientificreports Distribution, source apportionment, and risk analysis of heavy metals in river sediments of the Urmia Lake basin

The anthropogenic heavy metal dissemination in the natural environment through riverine sediments
is a major ecological and public health concern around the world. This study gives insight into the
source apportionment and potential ecological and health risks of heavy metals in river sediments
of the Urmia Lake basin, a natural world heritage located in northwestern Iran. A comprehensive
sediment sampling was conducted in seven major rivers feeding the basin during the summer and
winter of 2021. Samples were analyzed for zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb), and
nickel (Ni) contents and a suite of chemical and physical properties. Subsequently, Pollution Index
(PI), Pollution Load Index (PLI), Ecological Risk (ER), Hazard Quotients (HQ), Hazard Index (HI), and
Carcinogenic Risk (CR) indices were determined. The mean concentration of heavy metals in all rivers’
sediments exhibited the descending order of Ni > Zn > Pb > Cu > Cd during both summer and winter.
Multivariate analysis suggested that Zn was primarily initiated from natural processes, Cd and Pb were
affected by human activities, and Cu along Ni were derived from natural and anthropogenic factors.