Abstract
The impacts of the SAMARCO iron tailing spill along more than 650 km, between the dam and the plume of the Doce River in the Atlantic, were assessed by the determination of toxic metals. The tailing spill caused a substantial increase in suspended sediment loads (up to 33,000 mg L−1), in addition to large depositions of waste along the Doce basin. The highest estimated transport of dissolved metals was observed for Fe (58.8 μg s−1), Ba (37.9 μg s−1) and Al (25.0 μg s−1). Sediments reached the highest enrichment factors (EFs) for Hg (4,234), Co (133), Fe (43), and Ni (16), whereas As (55), Ba (64), Cr (16), Cu (17), Mn (41), Pb (38) and Zn (82) highest EFs were observed for suspended particulate matter (SPM). Iron, As, Hg, Mn exceeded sediment quality guidelines. Therefore, the risk of occurrence of adverse effects is highly possible, not only due to the dam failure, but also due to the Fe mining and the artisan Au mining. Heavy rain episodes will likely cause enhanced erosion, remobilization, and transport of contaminated particles, sustaining high inputs of SPM and metals for the years to come and threatening the ecosystem services.
Highlights
Most of the elements currently used in industrial applications, technology development, and energy generation are produced through the mining, extraction, and processing of mineral ores
The long-term effects of dam failures have been found to depend on four factors[3]: (1) the quantity and (2) characteristics of the waste, (3) the rate at which waste is discharged into a river system and (4) the effectiveness of cleanup procedures
It has been estimated that more than 35 million m3 of mining residues slid down a mountainside when Fundão tailing dam (SAMARCO) failed, causing the death of 19 people, and transforming more than 650 km of rivers (Gualaxo do Norte, Carmo and Doce rivers; Fig. 1), which were the primary source of water and food for several communities, in a “sea” of red mud
Summary
Most of the elements currently used in industrial applications, technology development, and energy generation are produced through the mining, extraction, and processing of mineral ores. According to Lewin and Macklin[2] tailing wastes may have a passive dispersion, i.e. tailing is transported alongside the natural sediment load of a river in a manner that does not disrupt natural systems, or they may undergo an active transformation. In the latter, the whole fluvial system is transformed through the input of wastes causing a dramatic increase in sediment supply and significant changes in the morphology of river basins.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
