Investigation And Analysis Of Heavy Metal Pollution And Mineral Element Content Characteristics Of Rice In China’s Main Rice Producing Areas

Because of its planting mode and plant characteristics,rice plants are easy to absorb and enrich heavy metals in the environment.To explore the heavy metal pollution status and potential risks of rice from Chinese major production areas,17 major rice producing provinces and Chinese cities were selected,and 450 rice samples were collected,then using inductively coupled plasma mass spectrometry(ICP-MS)and inductively coupled plasma emission spectrometry(ICP-AES)to detect the total amount of nine heavy metals,including Cr,Cd,As,Pb,Hg,Co,Ni,Cu,Mn;and the content of five mineral elements,Ca,Mg,Se,Fe,and Zn.The correlation analysis and principal component analysis are applied to identify the sources of heavy metals.The single pollution index method and comprehensive pollution index method are performed to evaluate heavy metal pollution,and analyzing the accumulation of mineral elements in rice.Providing a more comprehensive theoretical and reference basis for the prevention and control of heavy metal pollution in rice,the healthy development of future agricultural industry,and the improvement of residents’ health level and quality of life in China.Summarize the entire text and draw the following conclusions:1.The average values of Cr,Cd,Pb,As and Hg concentrations were all lower than the limits of national food safety standards.The contamination level of Cd in rice was the most serious,with a point exceedance rate of 11.56%,followed by Cr with a sample exceedance rate of 10.23%,Pb with a rate of 6.89% and As with a rate of 1.78%,and the detection of Hg was all lower than the national standards.The severity of heavy metal contamination was Cd>Cr>Pb>As>Hg.The concentrations of heavy metals Cd,Pb,Cr and Ni showed strong variation,while the contents of Co,Hg,Cu,As and Mn showed moderate variation,with the largest variation coefficient of Cd.2.Cr,Cd,Pb,As,Hg five elements are single factor no pollution risk level,in the clean level,heavy metal hazard coefficient size order As>Cr>Pd>Cd>Hg,Pb pollution risk peak is the largest,there are point source pollution;comprehensive factor pollution index of 0.701,the overall performance of the alert limit level,the evaluation results show no pollution risk >near the alert limit > slight pollution risk > moderate pollution risk > heavy pollution risk,moderate pollution risk sample points are distributed in the northwest of Guangxi,north of the eastern part of Hunan,heavy pollution risk sample points are scattered in Guangxi,Sichuan and other places,the peak sample points are located in Suibin County,Heilongjiang..3.The distribution of Cu in rice shows a typical step pattern in the study area,while Cd,Hg,Co,Ni and Mn show a more obvious bifurcated distribution.Cd,As,Pb,and Hg are enriched in north-central Hunan and northwest Guangxi,and the enrichment sites are mostly near the grain crop base;Cr,Co,and Ni are enriched in north-central Jiangxi and north-central Hubei;phosphate and coal mines are distributed near the high-value areas,and Cu is obviously enriched in central Zhejiang and northern Jiangxi;Mn is enriched in southern Heilongjiang and eastern Jilin;Zn and Fe are concentrated in Sichuan,Fe high value areas are concentrated in the northeast region of Sichuan;rice Ca content high value areas are concentrated in the eastern north of Sichuan,Mg high content areas are located in the southeast region of Sichuan and north China,the distribution and Mn show antagonistic phenomenon.4.The highest average element of rice mineral elements was Mg and the lowest was Se.The contents of Zn and Mg and Fe were highly significantly and positively correlated;two and two highly significantly and positively correlated among three mineral elements,Fe,Zn and Se.The content characteristics of Fe and Zn were correlated and regulated by similar anthropogenic or natural phenomena;the coefficient of variation of Se was the largest,and the overall coefficient of variation of the five mineral elements showed that Se(98.95%)>Fe(92.95%)>Zn(39.83%)>Ca(37.42%)>Mg(12.21%).5.Ca in rice was evenly distributed in the study area;the distribution characteristics of Ca and Mg were antagonistic to Cd and other polluting heavy metals,and the distribution characteristics of Mg showed obvious antagonism with Mn;the northeast region of Hunan and the north-central Jiangxi were enriched in Fe and Zn;the high value area of Se was concentrated in Guangxi.