Geochemistry of surface sediments and heavy metal contamination assessment: Messolonghi lagoon complex, Greece

Abstract

The Messolonghi lagoon complex in Western Greece receives agricultural and domestic effluents both from point and diffused sources. Surface sediments were analyzed for grain size, organic carbon, total nitrogen, total sulfur, major and minor elements, aiming at the identification of geochemical relationships between all variables. Enrichment factors and the modified degree of contamination methods were applied to assess potential heavy metal enrichment related to human activities. Sediment texture was highly variable, with muddy sediments prevailing. In the central sector of the Messolonghi lagoon, organic carbon contents were high. Principal factor analysis revealed the following main groups of variables with common geochemical behavior: (1) terrigenous aluminosilicates (2) organic matter, (3) biogenic carbonates, (4) mineral quartz-aluminosilicates, and (5) Mn-oxides. Enrichment factors estimated for V, Cr, Mn, Co, Ni, Cu, Zn, and Pb using local pre-industrial sediment showed that all metals exhibit almost natural background levels, except for Pb, which was found to be slightly elevated (legacy of leaded fuel). Estimation of contamination factors concluded in similar results, whereas the overall modified degree of contamination was at the lowest level, therefore suggesting that this transitional water body has not been affected by anthropogenic activities. The data set may be considered as a baseline for future monitoring projects according to EU policy.

Critical Processes of Trace Metals Mobility in Transitional Waters: Implications from the Remote, Antinioti Lagoon, Corfu Island, Greece

“…Trace metals enter coastal lagoons through several pathways, such as atmospheric depositions [1], industrial and urban discharges [2,3], agricultural run-off [4,5], riverine inputs [6], groundwater discharges [7], as well as benthic fluxes [8,9]. Upon reaching the lagoons, trace metals, under variable physicochemical gradients, participate in a series of complex physical, geochemical, and biological processes that greatly affect the distribution of trace metals over the particulate and dissolved phases, as well as the composition of the deposited sediment, and eventually, the fluxes of metals that reach the adjacent sea.…”

A 10-Year Statistical Analysis of Heavy Metals in River and Sediment in Hengyang Segment, Xiangjiang River Basin, China

“…Heavy metal elements in fluvial systems are known for their potential toxicity and ecotoxicity. These elements, including chromium (Cr), manganese (Mn), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb), are introduced into rivers by natural processes such as weathering and atmospheric deposition, and more importantly, via anthropogenic discharges from mining and smelting activities [1][2][3][4]. The control and treatment of heavy metal pollution in river and sediment has long been a serious campaign in most nations with intensive smelting activities.…”

“…The statistical analysis serves as a conventional and the most prevalent empirical approach to the characterization and exploration of the data. A variety of statistical procedures were used by environmental and geochemical researchers to reveal characteristics and structures within the data, such as outlier identification, correlation analysis, principal component analysis (PCA), factor analysis (FA), and regression modeling [1,[6][7][8][9][10][11]. Generally, the first step in statistical data analysis is to perform descriptive and exploratory statistical procedures that focus on single-variable data analysis, which helps one to gain a global understanding of the data and subsequently avails unbiased design and interpretation of further data analyzing procedures.…”

Geochemical Assessment of Trace Element Pollution in Surface Sediments from the Georges River, Southern Sydney, Australia

“…The main sources of contamination in estuaries are derived from catchment area runoff and include mining, industries, commercial waste, urban development, sewage discharge, agricultural and irrigation runoff, and atmospheric deposition (Karageorgis et al, 2012;Cheng et al, 2015;Singovszka et al, 2015;Kim et al, 2016). In addition, contamination may come from boat moorings and boatyards within bays, dredging, localized oil pollution, and the use of antifouling products, anticorrosive paints and metallurgical processing (Attia et al, 2012;Tarique et al, 2012;Zhang et al, 2012).…”

“…When changes in environmental conditions occur, the resultant chemical (pH and Eh), physical (temperature and turbidity) and biological processes can release contaminants back into the water column. This secondary contamination can have a significant effect on marine ecosystems (Karageorgis et al, 2012;Naser, 2013). Accumulation of trace element pollution occurs in the upper layer of sediments in aquatic environments through geochemical and biological processes and may become toxic to sediment-dwelling organisms and fish (Cosentino et al, 2013;Li et al, 2013).…”