Accumulation Of Zinc By Different Indica Rice Varieties And Its Health Risks

An investigation was carried out on 24 indica rice varieties and the corresponding surface soil,including 373 pairs of soil and rice samples collected from various sites over Fujian Province,China.The contents of total and DTPA-extractable soil Zn,the basic soil properties,and the Zn content in brown rice were determined.The factors influencing Zn accumulation and the availability of Zn in the soils,the relationship between Zn content in brown rice and the soil parameters,and the potential risks to human health of Zn by consuming the brown rice were evaluated.(1)The p H values of the soils were 3.90?7.62 with a mean of 5.20.CEC of the soils were 1.5 cmol(+)/kg?53.0 cmol(+)/kg with an average of 10.87 cmol(+)/kg.The organic matter contents were 2.8 g/kg?109.0 g/kg with a mean of 31.05g/kg.(2)The contents of total soil Zn were 11.2 mg/kg?233.0 mg/kg with an average of 88.81 mg/kg.There was only one soil sample of which the total Zn content exceeded the screening value(200 mg/kg)according to "soil environmental quality,risk control standard for soil contamination of agricultural land"(GB 15618-2018).The total soil Zn was significantly correlated with soil CEC while negatively correlated with sand particle content.(3)The DTPA-extractable Zn of the soils was 0.26?19.45 mg/kg with a mean of 3.76 mg/kg.The DTPA-extractable Zn was positively correlated with the total soil Zn while was negatively correlated with sand particle content.There was no significant correlation between The DTPAextractable Zn and soil organic matter content,CEC and p H.(4)The Zn content in brown rice was 0.9?56.3 mg/kg with an average of 15.65 mg/kg.Stepwise regression analysis showed that the Zn content of brown rice was significantly influenced by organic matter content,silt content and DTPA-extractable Zn.Lower organic matter content,higher contents of silt particles and the DTPA-extractable Zn favored Zn accumulation in brown rice.(5)The Zn contents of brown rice were lowest in Y liangyou 5866 and highest in Shiji 137.The accumulation ability for soil Zn was strongest for Yongyou 6 and Jiafuzhan while was lowest for Y liangyou 5866.(6)The daily Zn intake(DIM)and health risk index(HRI)suggested that there was no health risks by consuming the brown rice of most of the indica rice varieties by both adult and children.The potential health risks may occur when one consumes the brown rice with the highest Zn content.