Distribution, sources, and contamination evaluation of heavy metals in surface sediments of the Qizhou Island sea area in Hainan, China.

Coastal areas are regions of active interaction between the sea and land and are highly sensitive to changes in heavy metal contamination caused by natural and anthropogenic activities. The contents of heavy metals in 80 surface sediments in the Qizhou Island sea area in the northeast of Hainan Island were determined to assess the contamination status, spatial distribution, sources, and ecological risks. The results indicate that the main factors influencing the distribution patterns and contents of heavy metals are hydrodynamic conditions and sources of materials.

WITHDRAWN: Comparison of the Application Effects of Tissue-Selecting Therapy Stapler, Procedure for Prolapse and Hemorrhoids, and Ruiyun Procedure for Hemorrhoids in the Treatment of Mixed Hemorrhoids.

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Heavy metals and Pb isotopes in sediment cores from the Bering and Chukchi seas: Implications for environmental changes and human activities over the past century.

The Bering Sea and the Chukchi Sea are important regions for marine ecosystems and climate change. However, the historical deposition and sources of metals in these regions are poorly understood. In this study, we utilized Pb isotopes and multi-element concentrations (Ni, Cu, Fe, Mn, Zn, Cd, Pb) coupled with Pb-210 dating to investigate the historical deposition and source identification of metals in sediment cores collected from the Bering Sea and the Chukchi Sea.

Heavy metals in the sediments of Laoshan Bay, China: Distribution and contamination assessment.

We analyzed total organic carbon (TOC), total nitrogen (TN), and heavy metals in 58 sediment samples from the Laoshan Bay, China. TOC and TN results identified marine primary production as the dominant source for organic matter, and the weak correlations between TOC, TN, and heavy metals indicated the terrestrial origin of heavy metals. Cd showed insignificant correlations with other metals, which suggests that agriculture production is the main anthropogenic activity affecting the distribution of Cd.

Reassessment of heavy metal pollution in riverine sediments of Hainan Island, China: sources and risks.

Riverine sediment samples from Hainan Island were collected in 2013 to assess the heavy metal pollution levels, sources, and associated environmental risks. The concentrations of Cr, Ni, Cu, Zn, As, Cd, and Pb measured in this study were 31.6-128.

Improved source apportionment of PAHs and Pb by integrating Pb stable isotopes and positive matrix factorization application (PAHs): A historical record case study from the northern South China Sea.

To obtain the historical changes of pyrogenic sources, integrated source apportionment methods, which include PAH compositions, diagnostic ratios (DRs), Pb isotopic ratios, and positive matrix factorization (PMF) model, were developed and applied in sediments of the northern South China Sea. These methods provided a gradually clear picture of energy structural change. Spatially, ΣPAH (11.

Environmental background values of trace elements in sediments from the Jiaozhou Bay catchment, Qingdao, China.

Selected trace elements (As, Cr, Zn, Cu, Cd, Co, Pb and Ni) in 76 surface sediment samples collected from the rivers and the intertidal zone of Jiaozhou Bay (JZB) were evaluated to assess their environmental background values in the JZB catchment. Overall, the sediment quality in the area meets the China Marine Sediment Quality criteria. The background values (ranges) of the elements As, Cr, Zn, Cu, Cd, Co, Pb and Ni were, respectively, 8.

Heavy metals in the surface sediments of the northern portion of the South China Sea shelf: distribution, contamination, and sources.

The concentrations of seven heavy metals (Cr, Ni, Cu, Zn, As, Cd, and Pb) in the surface sediments of the northern portion of the South China Sea (SCS) shelf collected between 2012 and 2014 were measured to assess the potential contamination levels and determine the environmental risks that are associated with heavy metals in the area. The measured concentrations in the sediments were 12.4-72.

Trace metals in the surface sediments of the intertidal Jiaozhou Bay, China: Sources and contamination assessment.

The major (Al) and trace metal (Cu, Pb, Zn, Cr, Cd, and As) concentrations in 29 surface sediment samples from the intertidal Jiaozhou Bay (JZB) are evaluated to assess the contamination level. The results show that the overall sediment quality in the area has been obviously impacted by trace metal contamination. The geoaccumulation index and the enrichment factor values indicate that no Cr or Cu contamination has occurred on the whole, only a few stations have been polluted by As, and some areas have been polluted by Cd, Pb, and Zn.

Trace metals in the surface sediments of the eastern continental shelf of Hainan Island: Sources and contamination.

Major (Al) and trace metal (Cu, Pb, Zn, Cr, Ni, Cd, and As) concentrations in 29 surface sediment samples from the eastern continental shelf of Hainan Island were evaluated to determine the level of contamination. A multivariate analysis indicated that the sources of Cd, As, and Pb were primarily anthropogenic, whereas the sources of Cu, Zn, Cr, and Ni were primarily natural and/or partially anthropogenic. Enrichment factor (EF) and geoaccumulation index (Igeo) values were calculated to assess the anthropogenic contamination in the region.