Ecological criteria for zinc in Chinese soil as affected by soil properties.

The increasing accumulation of zinc (Zn) in agricultural soils has led to the need to assess the potential risk of this element for terrestrial organisms. However, the soil ecological criteria in agricultural soil as a function of soil properties have been sparsely reported. In the present study, we derived the ecological criteria (expressed as predicted no effect concentration (PNEC)) for Zn in soils, based on ecotoxicity data for 19 terrestrial species in Chinese soils, the effect of soil properties on Zn ecotoxicity, differences in species sensitivity, and differences between laboratory and realistic field conditions.

Soil ecological criteria for nickel as a function of soil properties.

Scientific information for the chemistry and ecotoxicology of metals in soils has been obtained in the research conducted in recent years. However, the latest "science" obtained from this research has not yet been translated into "regulations" in China. In the present study, the predicted no effect concentrations (PNECs) for Ni which denoted as soil ecological criteria for Ni were derived based on the effects of soil properties on bioavailability/ecotoxicity of Ni, incorporating the differences in species sensitivity as well as in laboratory and field conditions.

A new model integrating short- and long-term aging of copper added to soils.

Aging refers to the processes by which the bioavailability/toxicity, isotopic exchangeability, and extractability of metals added to soils decline overtime. We studied the characteristics of the aging process in copper (Cu) added to soils and the factors that affect this process. Then we developed a semi-mechanistic model to predict the lability of Cu during the aging process with descriptions of the diffusion process using complementary error function.

[Tobacco cadmium health risk assessment and reduction techniques: A review].

Tobacco is one of the cadmium accumulation and tolerance plants. Decreasing cadmium content of tobacco contributes to environmental safety and human health. Three aspects on tobacco cadmium research were reviewed in this paper, i.

Predicting Soluble Nickel in Soils Using Soil Properties and Total Nickel.

Soil soluble nickel (Ni) concentration is very important for determining soil Ni toxicity. In the present study, the relationships between soil properties, total and soluble Ni concentrations in soils were developed in a wide range of soils with different properties and climate characteristics. The multiple regressions showed that soil pH and total soil Ni concentrations were the most significant parameters in predicting soluble Ni concentrations with the adjusted determination coefficients (Radj2) values of 0.

Derivation of Soil Ecological Criteria for Copper in Chinese Soils.

Considerable information on copper (Cu) ecotoxicity as affected by biological species and abiotic properties of soils has been collected from the last decade in the present study. The information on bioavailability/ecotoxicity, species sensitivity and differences in laboratory and field ecotoxicity of Cu in different soils was collated and integrated to derive soil ecological criteria for Cu in Chinese soils, which were expressed as predicted no effect concentrations (PNEC). First, all ecotoxicity data of Cu from bioassays based on Chinese soils were collected and screened with given criteria to compile a database.

Field evidence of cadmium phytoavailability decreased effectively by rape straw and/or red mud with zinc sulphate in a Cd-contaminated calcareous soil.

To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables.

Development of a multi-species biotic ligand model predicting the toxicity of trivalent chromium to barley root elongation in solution culture.

Little knowledge is available about the influence of cation competition and metal speciation on trivalent chromium (Cr(III)) toxicity. In the present study, the effects of pH and selected cations on the toxicity of trivalent chromium (Cr(III)) to barley (Hordeum vulgare) root elongation were investigated to develop an appropriate biotic ligand model (BLM). Results showed that the toxicity of Cr(III) decreased with increasing activity of Ca(2+) and Mg(2+) but not with K(+) and Na(+).

Major controlling factors and predictions for cadmium transfer from the soil into spinach plants.

Predicting the mobility, bioavailability and transfer of cadmium (Cd) in the soil-plant system is of great importance with regards to food safety and environmental management. In this study, the transfer characteristics of Cd (exogenous salts) from a wide range of Chinese soils to spinach (Spinacia oleracea L.) were investigated.

[Toxicity and accumulation of copper and nickel in wheat plants cropped on alkaline and acidic field soils].

Field experiments were conducted to study the toxicity of added copper (Cu) and nickel (Ni) in soils to wheat and metal accumulation in wheat plants. The results showed that the yields of wheat straw and grain were decreased with the increasing concentration of Cu and Ni added to soils. The added Cu concentrations yielding 10% inhibition of wheat yield (EC10) were 499.

Genotypic variations in the accumulation of Cd exhibited by different vegetables.

It is an important approach to use the Cd-contaminated soils properly by growing low accumulator or excluder plants for Cd to produce safe foods. To find the suitable vegetable species for growing in Cd-contaminated soils, in the present study the variations in the Cd accumulation for twenty eight vegetable species and several cultivars of five common vegetables (cowpea, kidney pea, bitter gourd, cucumber and squash) were investigated in two soil Cd levels (1 and 2 mg/kg Cd). Experimental results showed that highly significant differences in Cd concentration were evident among 28 vegetables.

[In situ immobilization remediation of heavy metals-contaminated soils: a review].

In situ immobilization of heavy metals in contaminated soils by adding extraneous active amendments has been considered as a cost-effective measure for contaminated soil remediation. Application of immobilization amendments can decrease the available fractions of heavy metals or change their redox states, and thus, effectively decrease the mobility, bioavailability, and toxicity of the heavy metals in soils. This paper summarized the present researches about the in situ immobilization of heavy metals in soils, including kinds of immobilization amendments, research methods, immobilization indexes, immobilization mechanisms, and relevant environmental risk assessment.

An inventory of trace element inputs to agricultural soils in China.

It is important to understand the status and extent of soil contamination with trace elements to make sustainable management strategies for agricultural soils. The inputs of trace elements to agricultural soils via atmospheric deposition, livestock manures, fertilizers and agrochemicals, sewage irrigation and sewage sludge in China were analyzed and an annual inventory of trace element inputs was developed. The results showed that atmospheric deposition was responsible for 43-85% of the total As, Cr, Hg, Ni and Pb inputs, while livestock manures accounted for approximately 55%, 69% and 51% of the total Cd, Cu and Zn inputs, respectively.