Won Il Kim

Transfer Factor of Heavy Metals from Agricultural Soil to Agricultural Products

BACKGROUND: The Transfer Factor (TF) of heavy metals from soil to plant is important, because TF is an indicator of heavy metal in soils and a factor that quantifies bioavailability of heavy metals to agricultural products. This study was conducted to investigate the transfer ability of Arsenic (As), Cadmium (Cd), and Lead (Pb) from soil to agricultural products. METHODS AND RESULTS: We investigated heavy metals (As, Cd and Pb) concentrations in 9 agricultural products (rice, barely, corn, pulse, lettuce, pumpkin, apple, pear, tangerin) and soil. TF of agricultural products was evaluated based on total and HCl-extractable soil concentration of As, Cd, and Pb. Regression analysis was used to predict the relationship of total and HCl-extractable concentration with agricultural product contents of As, Cd, and Pb. The result showed that TF was investigated average 0.006~0.309 (As), 0.002~6.185 (Cd), 0.003~0.602 (Pb). The mean TF value was the highest as rice 0.309 in As, lettuce 6.185, pear 0.717, rice 0.308 in Cd, lettuce 0.602, pumpkin 0.536 in Pb which were dependent on the vegetable species and cereal is showed higher than fruit-vegetables in As. CONCLUSION(S): Soil HCl-extractable concentration of As, Cd, and Pb had the larger effects on thier contents in agricultural products than total soil concentrations. We suggests that TF are served as influential factor on the prediction of uptake. Further study for uptake and accumulation mechanism of toxic metals by agricultural products will be required to assess the human health risk and need TF of more agricultural products.

Contrasting effect of phosphate on phytoavailability of arsenic and cadmium in soils supporting medicinal plants

Soil and plant samples were collected from 84 fields where medicinal plants were cultivated to determine the effect of soil phosphate (P) on the concentration of plant-available arsenic (As) and cadmium (Cd) and on the uptake of these toxic elements by medicinal plants. Concentrations of total P and available P in soils affected the phytoavailability of As and Cd differentially. Plant-available As in the soil and its uptake in the plant increased with increasing concentration of plant-available P in the soil due to competition between arsenate and P for the adsorption site at the soil surface and an increase in soil pH caused by specific adsorption of P. In contrast, phytoavailability of Cd decreased with increasing concentration of available P in soil. This was mainly attributed to an increase in Cd adsorption caused by P-induced negative charge of soil.

The relationship between SO2 exposure and plant physiology: A mini review

Air pollutants are emitted from various sources into the atmosphere. During winter, greenhouses are heated by the burning of fuel in heating systems, which creates sulfur dioxide (SO2) that can be detrimental to plant growth and human health. However, there is a poor understanding of the comprehensive effects of SO2 on crops in a greenhouse environment. Therefore, this review aimed to summarize the impacts of greenhouse heating system-derived SO2 on the physiological, morphological, and biochemical responses of plants. In general, plant SO2 exposure has a negative effect on these processes. An initial decline in physiological activities appears several days following SO2 exposure. Morphological and biochemical activities are also negatively affected by extensive SO2 exposure. However, since sulfur is an essential nutrient for plant growth, low-level SO2 exposure has a positive impact on plants. Atmospheric SO2 is taken up by the plant via the stomata, after which it is assimilated and used to synthesize sulfur-containing amino acids, such as methionine and cysteine. Sulfur-containing compounds are crucial for plant growth, and various physiological and biochemical processes. It was concluded that SO2 is a significant greenhouse pollutant, especially for crops.