Risk Assessment and Source Apportionment of Soil Heavy Metals under Different Land Use in a Typical Estuary Alluvial Island

Abstract

<jats:p>Understanding the environmental risks of soil heavy metals (HMs) and identifying their main sources are the essential prerequisites for the prevention and management of soil pollution. Based on a detailed survey of soil HMs (Cu, Cr, Ni, Zn, Pb, Cd, As and Hg) from different land use types (including agricultural land, construction land, wetland, and forest land) in an estuary alluvial island, the environmental risk and source apportionment of soil HMs were investigated. Altogether, 117 soil samples were taken in the study area to appraise the soil HMs environmental risk by using the geo-accumulation index (Igeo), potential ecological risk index (RI), and human health risk assessment (HRA) and to identify its main sources by using positive matrix factorization (PMF) model. The average concentrations of soil HMs (except As) surpassed their reference background values in China. There were no significant differenced in the mean concentrations of HMs in different land use types, except that the Hg concentration in the construction land was significantly higher than that in others. The results of Igeo showed that Cd pollution was unpolluted to moderately polluted, and that the others were unpolluted. The potential ecological risk level for Cd and Hg was “moderated potential risk”, while for Cu, Cr, Ni, Zn, Pb and As was “low potential risk”. Higher contamination was distributed at the west-central area. The results of the HRA indicated that the non-carcinogenic risk and the carcinogenic risk that human beings suffered from HMs in different land uses were insignificant. To more accurately identify the sources of soil HMs, the PMF model coupled with the GIS-spatial analysis was applied. The results showed that agricultural activities, natural source, industrial discharge and river transportation, and atmosphere deposition were the main determining factors for the accumulation of soil HMs in the study area, with the contribution rate of 24.25%, 23.79%, 23.84%, and 28.12%, respectively. The study provides an underlying insight needed to control of the soil HM pollutions for an estuary alluvial island.</jats:p>

Heavy Metals in Soil around a Typical Antimony Mine Area of China: Pollution Characteristics, Land Cover Influence and Source Identification

“…The potential ecological risk index (RI) was used to evaluate the all-round potential ecological risk due to heavy metal accumulation in soils [8,14,26,31,40,45]. The integrated RI is calculated by the following Formulas (3) and ( 4): Table S3 summarized the classification of i r E and RI grades for heavy metal contamination.…”

“…Land cover is an important factor affecting the distribution and accumulation heavy metals in soils [24,26,57]. According to surrounding land vegetation, the land cover around the mining area where soil samples were collected included plowland, grassland, woodland and bare land.…”

“…In recent years, an increasing number of studies have focused on using mathematical models and statistical analysis to identify the potential sources of heavy metals in soils surrounding typical mining areas [18][19][20][21][22][23]. In addition to mine activities, land use is also an important factor affecting concentration and distribution of heavy metals in the soil [24][25][26]. For example, the soil over the Xiaoqinling gold-mining region was polluted by Hg, Pb, Cu and As, among which Hg, Pb and Cu pollution was caused by gold-mining activities, whereas As pollution was caused by agricultural activities [18].…”

Pollution Risk Assessment and Sources Analysis of Heavy Metal in Soil from Bamboo Shoots

“…As we all know, heavy metals in soils come from a wide range of sources, mainly including weathered parent materials, the impact of mining, transportation emissions, smelting products, fertilizer application, and other industrial, agricultural, and commercial activities [ 24 , 25 ]. Based on the World Health Organization, the Ministry of Environmental Protection of the People’s Republic of China and the United States Environment Protection Agency, heavy metal contamination will affect soil quality and crop growth, and with the increase of their content, they will pose a serious threat to the ecosystem and human health through different exposure pathways [ 26 ]. Excessive accumulation of soil heavy metals in plants will destroy soil quality and affect the growth and metabolism of plants, and endanger water and the atmospheric environment, exacerbate global climate change, and affect sustainable social development.…”

Application of Geostatistical Analysis and Random Forest for Source Analysis and Human Health Risk Assessment of Potentially Toxic Elements (PTEs) in Arable Land Soil

“…Arable land soil is fundamental to the survival of animals and plants, representing an important resource and basic element for human survival and development as well as being an important part of the terrestrial ecosystem [ 1 ]. Cd, Hg, As, Pb, and Cr are five common potentially toxic elements (PTEs) in arable land [ 2 ]. However, when PTEs accumulate in the arable land soil in considerable amounts, leading to a decrease in the quality of the crops and inhibit the life activities of organisms, and pass through the food chain to enter animals and humans, and enter through exposure pathways such as skin contact and inhalation, posing a huge menace to food safety and human health [ 3 ].…”