Occurrence, Risk, and Source of Heavy Metals in Lake Water Columns and Sediment Cores in Jianghan Plain, Central China

Abstract

Heavy metal pollution in lakes is an issue that endangers ecosystems worldwide; however, the vertical properties of heavy metals in the water columns and sediment cores of lakes have been rarely evaluated simultaneously. This study revealed the pollution, risks, and sources of heavy metals from surface water to deep sediments in four typical lakes located in central China. The results showed that the concentrations of heavy metals, except Hg, had insignificant stratification in the water column. Heavy metals had three vertical profiles in sediment cores, i.e., the concentrations of As, Hg, Cd, Pb, and Mn in the surface sediment (0–9 cm) were higher than that in the bottom sediment (9–45 cm) (p < 0.05), the concentrations of Cr, Co, Fe, and Ni in the bottom sediment were higher than the surface sediment (p < 0.05), and the concentrations of Cu and Zn had no significant stratification. The Nemerow pollution index showed that heavy metal pollution dominated by Hg reached slight–moderate levels, and had higher levels in surface water than that in bottom water (p < 0.05). The Nemerow integrated risk index showed that the heavy metals had moderate–extreme potential ecological risks (Cd contributed 43.4%) in the sediments, and the ecological risk in surface sediment was significantly higher than that in bottom sediment (p < 0.01). Principal component analysis revealed that agriculture, transportation, and chemical industry were the major sources of heavy metals in water and surface sediments f, while agriculture and steel-making were the primary sources in bottom sediments. This study provides valuable data and insight for the control of heavy metal pollution in lakes with high human activity loads.

Spatial Distribution, Risk Index, and Correlation of Heavy Metals in the Chuhe River (Yangtze Tributary): Preliminary Research Analysis of Surface Water and Sediment Contamination

“…Likewise, most of our heavy metal values were similar or in range with the Chaohu, Taihu, and Poyang lakes, indicating that heavy metal pollution in surface waters is a massive problem most freshwater ecosystems face [44]. Most of these lakes are prone to agricultural runoffs, discharges from wastewater treatment plants, and anthropogenic activities [3,9,10]. However, we did observe that our heavy metal concentrations for surface water were higher than the concentrations found in the middle and lower parts of the Yangtze River [7,45]; we believe that this could be due to the exposure of this tributary to an excessive agricultural runoff that caused elevated levels of heavy metals, as this was also observed by [38,46].…”

“…We measured eight heavy metals in surface water and sediment samples: Arsenic, Mercury, Chromium, Nickel, Copper, Zinc, Cadmium, Lead, and Manganese. We followed the pre-treatment protocol mentioned by [3,12] to prepare the samples for heavy metal quantification. All of the chemical reagents used were of a ≥99% purity grade.…”

“…In sediment samples, Factor 1 explained 67.05% of the total variance and was strongly associated with concentrations of Cr, Ni, Zn, and Cd, indicative of common sources. These metals are widely found in fertilizers and sewage discharges [3,75].…”

“…Despite their natural existence in the environment, these freshwater ecosystems serve diverse functions, including water supply, agricultural irrigation, flood control, climate regulation, aquaculture, tourism, and biodiversity preservation [1]. Despite exponential economic growth, China faces escalating heavy metal concentrations in its freshwater sources, primarily attributed to urbanization, industrial activities, and modern agricultural practices [2,3].…”

Source-Specific Health Risk of PM2.5-Bound Metals in a Typical Industrial City, Central China, 2021–2022

“…With rapid economic development, Huangshia time-honored industrial city in Hubei Province is prone to environmental pollution, especially against the backdrop of nationwide frequent heavy pollution weather. It was found in numerous studies that the atmosphere [39], soil [40,41], sediment [42,43], street dust [44], and water bodies [45] in this region have serious over-proof heavy metals, posing a great danger to local ecological environmental safety and population health. So far, Huangshi is in the midst of industrial structural transformation and energy consumption structure adjustment to drive the development of non-fossil energy such as wind energy, solar energy, and biomass energy.…”