Heavy Metal Pollution and Potential Ecological Risk Assessment in a Typical Mariculture Area in Western Guangdong.

Kaifeng Sun,Lanzhou Liu,Ren Wei,Ning He

doi:10.3390/ijerph182111245

Abstract

The distribution characteristics, environmental contamination states, and potential ecological risks of chromium (Cr), copper (Cu), arsenic (As), lead (Pb), and cadmium (Cd) in seawater, sediment and breeding feed were studied in a typical mariculture area in western Guangdong of China. Pearson correlation analysis was used to determine metal homology, and the single-factor index, potential ecological risk index, hazard quotient (HQ), and joint probability curve (JPC) were used to evaluate pollution states and ecological risk of metals. Four main statements can be concluded from the results: (1) Pb and Cu showed a similar distribution pattern in the seawater and sediment and their contents in the breeding wastewater exceeded the standard limits in several stations. (2) Cr, Cu, and As have similar sources in the feeds, which may be an important source of metals in water. (3) The risk assessment revealed that the sediment from the studied areas was at a low ecological risk of heavy metal, whereas, water in the pond and outfall was slightly polluted by Pb, and water in the cages and outfall were slightly polluted by Cu. (4) Both the hazard quotient (HQ) and joint probability curve showed the overall risk probabilities (ORPs) in the waters ranked as Cu > Cr > Pb > Cd > As. Although Pb and Cd had HQ values greater than 1, their ORPs were acceptable. This study highlights that multiple evaluation models are more reliable than the single ecological risk assessment for evaluating heavy metal pollution risks in the mariculture area.

Highlights

Coastal ecosystems provide considerable services and support for the development of human society, including cultural service, provisioning service, regulating service, and supporting service
The mean concentrations of Cr, As, Cd, and Pb in breeding water met the requirements of water quality for mariculture at the Nuisance-free Food Environmental Conditions in Seawater Farm Stations (NY 5362-2010), and the mean concentration of Cu was below the background level of Cu in the South China Sea
The concentration ranges of Cu and Pb in seawater and in sediment were wide while those of As and Cd were narrow (Figure 2)

Summary

Introduction

Coastal ecosystems provide considerable services and support for the development of human society, including cultural service, provisioning service, regulating service, and supporting service. Due to terrestrial urbanization and the rapid growth of coastal port development and trade, energy production, and aquaculture, large amounts of industrial and agricultural wastewater and urban domestic sewage are discharged into the offshore environment posing serious threats to the marine environmental quality and local ecological security [3,4]. Heavy metals enter the ocean via several major sources, most notably riverine influx, atmospheric deposition, and anthropogenic activities [5,6]. Heavy metals have continued to attract considerable attention worldwide due to their bioaccumulation, difficult degradation, and the high latency of their effects [9,10,11].

Methods

Results

Conclusion