Distribution and risk assessment of trace metals in sediments from Yangtze River estuary and Hangzhou Bay, China

Abstract

The Yangtze River estuary (YRE) and Hangzhou Bay (HZB) is of environmental significance because of the negative impact from industrial activities and rapid development of aquaculture on the south bank of HZB (SHZB) in recent years. This study investigated the distribution and risk assessments of trace metals (Cr, Cu, Zn, Hg, Pb, and Cd) accumulated in surface sediments by sampling in YRE, outer and south HZB. Copper and Zn concentration (avg. 35.4 and 98.7 mg kg, respectively) in surface sediments were generally higher than the background suggesting a widespread of Cu and Zn in the coastal area of Yangtze River Delta. High concentrations of Cu (~ 42 mg kg), Zn (~ 111 mg kg), Cd (~ 0.27 mg kg), and Hg (~ 0.047 mg kg) were found in inner estuary of YRE and decreased offshore as a result of terrestrial input and dilution effect of total metal contents by "cleaner" sediments from the adjacent sea. In outer HZB, accumulation of terrestrial derived metal has taken place near the Zhoushan Islands. Increase in sediment metal concentration from the west (inner) to the east (outer) of SHZB gave rise to the input of fine-grained sediments contaminated with metals from outer bay. According the results from geoaccumulation index, nearly 75% of samples from YRE were moderately polluted (1.0 < I < 2.0) by Cd. Cadmium and Hg contributed for 80~90% to the potential ecological risk index in the YRE and HZB, with ~ 72% sites in HZB under moderate risk (150 ≤ RI < 300) especially near Zhoushan Islands.

Bioaccumulation and potential human health risks of metals in commercially important fishes and shellfishes from Hangzhou Bay, China

“…The Hangzhou Bay, a typical funnel-shaped macrotidal estuary 47 , 49 , is located in the northern Zhejiang province, covering about 8500 km 2 40 . This area is surrounded by six megacities and nine industrial parks (Fig.…”

Effects of Human Activities on the Spatial Distribution, Ecological Risk and Sources of PTEs in Coastal Sediments

“…The potential ecological risks of PTEs in the surface sediment in Xiamen Bay were mainly caused by Cd and Hg ( Figure 7 ). Previous studies found that Hg and Cd had higher hazard risks for sediments along coastal regions in China [ 6 , 48 , 56 , 57 ].…”

Eco-Toxic Risk Assessment of Nearshore Sediments in Bay of Bengal - Environmental Radioactivity and Ecological Risk as a Proxy

“…The word organic matter is used to denote the part of the sediment formed by organic activities comprising of carbon another carbonate (Bonnail et al 2016). It can be named "marine humus" since it's a little similar to the humus fraction in soils (Li et al 2018). The spatial diagram for the distribution of sand-silt-clay ration, calcium carbonate, organic carbon and organic matter shows explicitly that they are produced from ocean drift to the off-shore by way of long-shore drifting sediments (Fig.…”