Contamination and Spatial Variation of Heavy Metals in the Soil-Rice System in Nanxun County, Southeastern China

Abstract

There is an increasing concern about heavy metal contamination in farmland in China and worldwide. In order to reveal the spatial features of heavy metals in the soil-rice system, soil and rice samples were collected from Nanxun, Southeastern China. Compared with the guideline values, elevated concentrations of heavy metals in soils were observed, while heavy metals in rice still remained at a safe level. Heavy metals in soils and rice had moderate to strong spatial dependence (nugget/sill ratios: 13.2% to 49.9%). The spatial distribution of copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in soils illustrated that their high concentrations were located in the southeast part. The high concentrations of cadmium (Cd) in soils were observed in the northeast part. The accumulation of all the studied metals is related to the long-term application of agrochemicals and industrial activities. Heavy metals in rice showed different spatial distribution patterns. Cross-correlograms were produced to quantitatively determine the spatial correlation between soil properties and heavy metals composition in rice. The pH and soil organic matter had significant spatial correlations with the concentration of heavy metals in rice. Most of the selected variables had clear spatial correlation ranges for heavy metals in rice, which could be further applied to divide agricultural management zones.

A Comparison of Reproducibility of Inductively Coupled Spectrometric Techniques in Soil Metal Analyses

“…According to Paya-Perez et al, 19 inherent interferences of some elements such as Zn were attributable to CV values greater than 100% in a comparative ICP-MS and ICP-OES study on soil pollution in Abardeen, UK. Zhao et al 28 suggested that soil's complex nature could be the reason for CV values of beyond 100% for Ni and Cr in Chinese soil-rice systems using atomic spectroscopy. In both analytical techniques, CV values of Ti and Fe were the lowest, whereas values of Co, Zn, Ni, and Sr were relatively the same, which could infer to the ability of the 2 techniques to quantify these elements precisely.…”

Potentially hazardous metals contamination in soil-rice system and it's spatial variation in Shengzhou City, China

“…Elsewhere, one can at best estimate Ω[Z(x) ≥ Z c ]. In fact, it is necessary to do this in such a way that the estimate at any place x 0 approximates the conditional probability, given the data, that Z(x) equals or exceeds Z c (Liu et al, 2006;Zhao et al, 2015).…”

Chemical Speciation and Fractionation Study of Heavy Metals in Top Sediment Deposit of Owena River, Nigeria

“…Soil pollution by heavy metals is a significant environmental problem worldwide. In particular, heavy metal pollution of surface soils due to intense industrialization and urbanization has become a serious concern in many developing countries [16][17][18]. Multi-elemental analysis of sediment may reveal the presence of heavy metals which are contaminants and may have toxic influence on ground water and surface water and also on plants, animals and humans [19].…”