Ecological risk and source apportionment of heavy metals in riparian soil and sediment of an urban river in a developing country.

There is no universally accepted safe level of heavy metals in the river watershed’s riparian soil and sediment in Bangladesh. To assess contamination, sources, and ecological risks of heavy metals in surface sediment and riparian soil of the most polluted urban river (Buriganga) in Bangladesh. A total of 45 surface sediment and 45 riparian soil samples were collected from the study river, and metals were measured by inductively coupled plasma mass spectrometer (ICP-MS). The mean values were observed as 59.2, 42.6, 88.5, 15.1, 6.4, 42.9, 12676.3, 55.0, and 129.0 mg/kg in riparian soil and 183.7, 134.4, 233.6, 22.2, 9.9, 155.4, 15860.3, 170.1, and 203.7 mg/kg in sediment, respectively for Cr, Ni, Cu, As, Cd, Pb, Fe, Mn, and Zn. Ecotoxicological estimation portrayed moderate pollution of heavy metals in the riparian soil and sediment of the Buriganga River. Most of the evaluated metals originated from anthropogenic sources (industrial and agricultural activities) rather than geogenic sources, and caused the severity of contamination of the river ecosystem. Heavy metals estimated in this study could provide reliable information for effective risk assessment of heavy metals in the urban area to maintain river health.