The Accumulation Of Sb By Different Rice Cultivars

In order to study the accumulation characteristics of soil Sb by different rice,and evaluate the health risks of Sb in rice grains,a survey over some districs(Longyan,Nanan,Longhai,Taining and Fuqing)in Fujian Province was carried out.130 rice samples of 14 rice cultivars and the corresponding surface soil samples were collected.The antimony(Sb)contents in the soils and rice were determined and the characteristics of absorption and enrichment were discussed.We also collected the root,stem,leaf and grains samples of 3 representative varieties,Te-you 009,Dong-lian 5 and Yi-you 673,and the corresponding surface soil samples for the study on the transfer characterics of Sb in the soil-rice systems.The risks of Sb in brown rice of these rice cultivars to human health through rice consumption were evaluated based on the above results.The main results were as follows:(1)The total soil Sb in the brown rice of various rice cultivars was 0.12～0.96 mg kg-1,with an average of 0.42 mg kg-1.The results of single factor index method showed that the soil was not polluted by Sb,while the total soil Sb in 28.5%the samples exceeded the background value of the soils in Fujian Province.The available soil Sb in the soils were between 0.018-0.274 mg·kg-1,with a mean of 0.114 mg·kg-1.The availabile fractionof soil Sbvaried between 9.77%and 52.79%with a mean of 25.92%.The available degree of soil Sb is not affected by the total Sb of soil.(2)The relationship between soil properties and soil Sb was different in different rice varieties.The total Sb in the soils of some rice cultivars was positively correlated with soil pH while negatively correlated with CEC and free iron oxides.The available fractions of Sb in the soils of some rice cultivars were negatively correlated with soil pH,free iron oxides,while positively correlated with CEC and organic matter content.(3)The Sb concnetration in brown rice was between 2.2μg·kg-1(Yiyou 673)14.8 μg·kg-1(Donglian 5).The average accumulation factors(based on available soil Sb)varied greatly with rice cultivars.The rice cultivars with low accumulation ability to soil Sb included Jia-fu-zhan,Yang-liang-you 6,Yi-you 673,and Tian-you 998.The accumulation of concentional rice to soil Sb was generally stronger than that of hybride rice.However,it was more difficult for the Sb in the roots of the conventional rice to be transpoted into the leaf although the Sb in the leaf of conventional rice was easier to get into rice grains.(4)The average daily intake by consuming food was between 2.7 and 17.6 μg,which was much lower than the daily maximum allowable intake of Sb(360 μg·d-1).It is concluded that the Sb in rice grains grown on non Sb-polluted soils may not harm human health.