Distribution, Enrichment and Ecological Risk Assessment of Six Elements in Bed Sediments of a Tropical River, Chottanagpur Plateau: A Spatial and Temporal Appraisal

Abstract

Distribution and enrichment of six elements (iron, zinc, copper, lead, cadmium and manganese) in surface bed sediments, collected from seventeen selected locations during pre-monsoon and postmonsoon periods, of the tropical Chottanagpur plateau river Subarnarekha along with the ecological risks involved were investigated. Owing to the rich occurrence of mineral resources, the Subarnarekha river basin has a large scale presence of industrial and mining units especially in the Indian State of Jharkhand. An assessment, which involved examining distribution pattern of elements, comparative studies with sediment quality guidelines (SQGs) and geochemical background values and a sequential and integrated index analyses approach (containing contamination factor (CF), pollution load index (PLI), contamination degree (CD), enrichment factor (EF), geo-accumulation index (Igeo) and potential ecological risk index (PERI)), was followed to estimate enrichment and risks of elements in the bed sediments. Sediments collected from areas having abundance of population, industrial conglomerates and mining units recorded elevated element concentrations, which exceeded SQGs, and significantly higher values of CF, CD, PLI, EF, Igeo and PERI. Cadmium demonstrated surprising regularity in its enrichment; contributed most to the ecological risks; and high toxicity risks due to cadmium exceeded 64% of the sites. Moreover, chronic exposures of other elements would also lead to similar ecological risks. In addition to revealing potential ecological risks due to cadmium and other elements our investigation markedly highlighted anthropogenic control over sediment quality deterioration and some immediate sediment quality management strategies are needed to remediate and control river bed contamination.

Evaluating the potential health risks of heavy metal pollution in sediment and selected benthic fauna of Benin River, Southern Nigeria

“…In a recent study, the spatial and temporal investigation by Manoj and Padhy (2014) showed Cd as the contaminant of chief concern. Cd concentration was noted above its geochemical background value throughout the studied area in both study periods.…”

Little Akaki River Sediment Enrichment with Heavy Metals, Pollution Load and Potential Ecological Risks in Downstream, Central Ethiopia

“…Besides, physical land scope (gentle flat land), hydrological flow (gently river flows conditions) and clay dominated particles size might have facilitated the adsorption and deposition of suspended metals. Consequently, highest PLI value reflects that the quality of sediments at this sample site was highly deteriorated due to high anthropogenic metal inputs (Al Obaidy et al 2014;Likuku et al 2013;Manoj and Padhy, 2014;Sekbira et al 2010).…”

“…Contamination factor is commonly used to demonstrate the level of contamination of sediment by particular toxic metal at a given sample site (Manoj and Padhy, 2014). It is defined as:…”

“…In all sampled sites, the CF values for Cd (CF> 6) found to be in (class-4), exhibiting very high (CF>6) level of sediment contamination. Cd can be generated from multiple sources of inputs in downstream, these include: electroplating, batteries, paints and pigments factories, garages, vehicles washing, domestic and municipal wastes (Mortazavi and Hatami, 2018), agricultural use of phosphorus, zinc and iron fertilizers (Manoj and Padhy, 2014).…”

Hydrochemistry and carbonate sediment characterisation of Bacalar Lagoon, Mexican Caribbean

“…Some trace elements in Bacalar Lagoon sediments may reflect anthropogenic pollution. Here we used four indices following Manoj and Padhy (2014; see Table 3). We normalised concentrations to Al because it is a conservative lithogenic element and is resistant to chemical weathering; hence, it does not actively participate in the dominant geochemical cycles and does not have a significant anthropogenic source (Boës et al 2011;Dautović et al 2014).…”