Heavy metals in surface sediments of the intertidal Thai Binh Coast, Gulf of Tonkin, East Sea, Vietnam: distribution, accumulation, and contamination assessment

Abstract

Heavy metals contamination in sediments may endanger ecosystems and human health via the food chain. In fact, there is little to no understanding about heavy metal accumulation in surface sediment of one of the most economically important marine bodies for Vietnam, the Thai Binh Coast, where ve large rivers co-discharge into the Gulf of Tonkin. Twenty-seven surface sediment samples were collected from the intertidal regions and analyzed for: arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), and zinc (Zn) using inductively coupled plasma mass spectroscopy (ICP-MS). The studied area exhibited a large spatial variation in the concentration of heavy metals, e.g., the dry sediment concentration of Cd was the least (0.05-0.49 mg.kg −1 ), whereas that of Zn was the greatest (45.4-252 mg.kg −1 ). Based on the geoaccumulation index (I geo ), most of the studied heavy metals were accumulated at low pollution levels, except four locations exhibited moderately and highly polluted levels of Hg with I geo Hg values from 1.92 to 2.66. Whereas the high contamination factor value implicated that not only Hg but also all other detected heavy metals in this area resulted from anthropogenic activities along the coast and the river upstream. This implied the need for quick action from the government.

Relation disentanglement, the potential risk assessment, and source identification of heavy metals in the sediment of the Changzhao Reservoir, Zhejiang Province

“…The interaction between different environmental factors also affects the migration and transformation of heavy metals in the sediment (Fu et al 2014). It has been pointed out that a high degree of positive correlation existed in different metals, and even many correlations reach 1 (Duong et al 2022). Organic matter and geochemical carriers such as iron and manganese oxides have signi cant effects on copper (Cu) and lead (Pb), and total organic carbon (TOC) can to some extent characterize the metal bioavailability in the pore water of sediment (Chiappetta et al 2016).…”