Development of a hybrid pollution index for heavy metals in marine and estuarine sediments

Abstract

Heavy metal pollution of sediments is a growing concern in most parts of the world, and numerous studies focussed on identifying contaminated sediments by using a range of digestion methods and pollution indices to estimate sediment contamination have been described in the literature. The current work provides a critical review of the more commonly used sediment digestion methods and identifies that weak acid digestion is more likely to provide guidance on elements that are likely to be bioavailable than other traditional methods of digestion. This work also reviews common pollution indices and identifies the Nemerow Pollution Index as the most appropriate method for establishing overall sediment quality. Consequently, a modified Pollution Index that can lead to a more reliable understanding of whole sediment quality is proposed. This modified pollution index is then tested against a number of existing studies and demonstrated to give a reliable and rapid estimate of sediment contamination and quality.

Accumulation of Arsenic and Heavy Metals in Native and Cultivated Plant Species in a Lead Recycling Area in Vietnam

“…The contamination factor (CF), which is calculated as the ratio of the metal content in the soil at each site to the regulatory limit, is used to assess of soil contamination [52]. In this study, the thresholds of As (15 mg/kg), Cr (150 mg/kg), Cu (100 mg/kg), Zn (200 mg/kg), Cd (1.5 mg/kg), and Pb (70 mg/kg) regulated by the Vietnam Ministry of Natural Resources and Environment for agricultural soils [53] were used to calculate the CF.…”

Hydrochemical characteristics of surface water and ecological risk assessment of sediments from settlements within the Birim River basin in Ghana

“…The modified degree of contamination (mC d ) which has an advantage over single element indices since it takes account the synergistic effect of the contaminants at a study site (Brady et al 2015) was calculated as follows: (Turekian and Wedepohl 1961;Hankason 1980) and C i f the contamination factor of each element.…”

Heavy metal contamination of agricultural soils affected by mining activities around the Ganxi River in Chenzhou, Southern China

“…The mC d value is graded into seven degrees (Brady et al 2015): mC d <1.5, unpolluted; 1.5≤mC d <2, slightly polluted; 2≤mC d <4, moderately polluted; 4≤mC d <8, considerably polluted; 8≤mC d <16, highly polluted; 16≤mC d <32, strongly polluted; and mC d ≥ 32, extremely polluted. The Nemerow index is classified into five groups (Wu et al 2015): P s < 1, uncontaminated; 1 ≤ P s < 2, slightly contaminated; 2 ≤ P s < 3, moderately contaminated; 3 ≤ P s < 5, strongly contaminated; and P s ≥5, seriously contaminated.…”

“…By using both the average of contamination factors and the maximum contamination factor according to Eq. (3), the Nemerow index allows the quantification of soil quality much more considerate of the impact of one single element (Brady et al 2015).…”