Heavy metal concentrations and ecological risk assessment of the suspended sediments of a multi-contaminated Brazilian watershed

Abstract

Metal concentrations in suspended sediments of one of the most polluted rivers in Brazil were measured. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma while Hg and As were analyzed with hydride generation flow injection atomic absorption spectroscopy. Contamination of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn was assessed using pollution indices, ecological risk assessment, statistical multivariate techniques and comparison with sediment quality guidelines. Suspended sediments of the upstream portion of the Ipojuca River are moderately contaminated, especially with Mn and As. On the other hand, sediments of the downstream section are highly contaminated, mainly with Zn, Pb, and As. Furthermore, the mean Ei (potential ecological risk) values of Pb and As showed considerable ecological risk in the downstream cross section. The comparison of our data with sediment guideline values indicated that the concentrations of Mn and Pb in the upstream section of the Ipojuca River pose a risk to sediment-dwelling organisms, while Pb and Zn are the metals of concern in the downstream section.

Heavy metals risk assessment of water and sediments collected from selected river tributaries of the Mara River in Tanzania

“…When EF values exceed 20, sediments are considered significantly enriched with metals. Such high EF values are usually associated with anthropogenic inputs [65]. The computed EF values in the present study indicate that the sediments were very highly to extremely enriched with respect to As and Cd regardless of sampling site and sampling period (Fig.…”

Risk assessment of heavy metal contamination in agricultural sites and river sediments at the Vatukoula gold mine, Fiji Islands

“…For sediments, it was observed that the concentrations of Pb, Zn, Cd and Cu from the Nasivi river were lower than the respective concentrations reported for the Suva Harbor in Fiji (Maata and Singh, 2008). While metal concentrations from this study were far below those reported for the Molonglo river in Australia (Marasinghe Wadige et al, 2016), they exceeded those reported for the Ipojuca river in Brazil (Silva et al, 2019)and the Jequetepeque River Basin in Peru (Yacoub et al, 2012).…”

Toxic Elements Contents and Associated Potential Ecological Risk in the Bottom Sediments of Hrazdan River Under the Impact of Yerevan City (Armenia)

“…The minimal mean contents are those in the Tinto River (Spain) which are of a point character and are due to a sulfide deposit operating in the vicinity of city of Narva (Morillo et al, 2002). In the Hrazdan River mean contents of Mn make 747mg/kg, which is very close to the values registered in bottom sediments of the Ipojuca (Da Silva et al, 2019). For the Hrazdan and the Ipojuca, no pronounced manganese pollution sources have been identified; in both cases, such contents of this element result from a discharge of untreated urban domestic waters into the rivers.…”

“…The Guadaira River (Spain) stands out by the minimal contents of elements and specifically arsenic, the only cause of which is the former olive processing workshop. The sampling locations are not currently exposed to anthropogenic impacts (Enguix González et al, 2000) In the bottom sediments of the Hrazdan River, mean contents of arsenic are similar to those in the Ipojuca River (Brazil) which flows through heavily populated settlements, where similarly to Yerevan, no pronounced arsenic pollution sources are found either (Da Silva et al, 2019).…”

“…In France, in the region adjoining the Gironde, once operated a zinc deposit, which is the cause of such contents of this element (Larrose et al, 2010). Relatively to the rest three rivers, no pronounced zinc pollution sources are identified either (Larrose et al, 2010) (Skorbiłowicz et al, 2016)(Da Silva et al, 2019) (Mortatti et al, 2013).…”