Variation of Cd concentration in various rice cultivars and derivation of cadmium toxicity thresholds for paddy soil by species-sensitivity distribution

• Published in: Journal of Integrative Agriculture Vol. 14; no. 9; pp. 1845 - 1854
• Main Authors: SONG, Wen-en, CHEN, Shi-bao, LIU, Ji-fang, CHEN, Li, SONG, Ning-ning, LI, Ning, LIU, Bin
• Format: Journal Article
• Language: English
• Published: Science Press 01.09.2015; Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China%Agricultural Information Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China%Institute of Plant Protection and Environmental Protection, Beijing Academy of Agricultural and Forestry Science, Beijing 100097, P.R.China; Elsevier
• Subjects: bioaccumulation factor; bioconcentration; bioconcentration factor; cadmium; cadmium rice cultivars bioconcentration factor species-sensitivity distribution toxicity thresholds; China; cultivars; distribution; factor; food safety; greenhouses; paddies; paddy soils; rice; rice cultivars; rice soils; risk; species-sensitivity; species-sensitivity distribution; straw; thresholds; toxicity; toxicity thresholds; China; cadmium; species-sensitivity distribution; toxicity thresholds; rice cultivars; bioconcentration factor
• ISSN: 2095-3119; 2352-3425
• DOI: 10.1016/S2095-3119(14)60926-6

It is imperative to derive an appropriate cadmium （Cd） health risk toxicity threshold for paddy soils to ensure the Cd con- centration of rice grains meet the food safety standard. In this study, 20 rice cultivars from the main rice producing areas in China were selected, and a pot-experiment was conducted to investigate transformation of Cd in paddy soil-rice system with 0 （CK）, 0.3 mg kg-1 （T1） and 0.6 mg kg-1（T2） Cd treatments in greenhouse. The results showed that Cd concentrations of rice grains existed significant difference （P〈0.05） in 20 rice cultivars under the same Cd level in soil. The Cd concentrations of rice grains of the CK, T1 and T2 treatments were in the range of 0.143-0.202, 0.128-0.458 and 0.332-0.806 mg kg-1, respectively. Marked differences of the ratios of Cd concentration for soil to rice grain （BCFs） and transfer factors （TFs, root to grain and straw to grain） among the tested cultivars were observed in this study. The bioconcentration factors （BCFgrain） and TFs of the 20 rice cultivars were 0.300-1.112 and 0.342-0.817, respectively. The TFs of Cd from straw to grain ranged from 0.366 to 1.71, with significant differences among these 20 rice cultivars. The bioconcentration factors （BCFgrain） and TFs among the 20 rice cultivars ranged from 0.300-1.112 and 0.342-0.817, respectively. The species-sensitivity distribu- tion （SSD） of Cd sensitivity of the rice species could be fitted well with Burr-Ill （R2=0.987） based on the data of BCFs. The toxicity threshold of Cd derived from SSD for the paddy soil was 0.507 mg kg-1 in the present study.