Enrichment Characteristic And Risk Assessment Of Heavy Metals In Rice (Oryza.sativa L.) From Suzhou Regions

The paddy soil and rice plants as pair samples were collected from different region in Suzhou at November 2016.The accumulation characteristic of elements?including chromium?Cr?,cadmium?Cd?,copper?Cu?,zinc?Zn?,lead?Pb?,nickel?Ni?,antimony?Sb?and vanadium?V??in roots,stems,leaves and seeds of rice was investigated by ICP-AES,and arsenic,selenium measured by ICP-AES and the exposure risk via consumption of local rice grains was elevated.This findings indicated that the average concentration of heavy metals?except for V and Ni?all excessed the Jiangsu Province background values.Most sampling sites were moderate pollution,influence index of comprehensive quality of 52%of paddy soil samples were higher than 3,considering the background value and standard value of different metals in soils.The over-standard ratio of Cr in rice grains were 33%.Most of metals were distributed mainly in the rice root,less in the rice grain.The enrichment coefficient of rice grain to elements decreased in the order of Cd>Zn>Se>Cu>Ni>V>As>Cr>Sb>Pb.Although target hazard quotients?THQ?of all elements via consumption of rice grain for all populations were lower than 1,hazard index?HI?was greater than 1,considering the cumulative lifetime exposure risk,the carcinogenic risk values of Cr and Ni in both adults and young people are>10^-4?suggesting an unacceptable risk?,which indicates that the local residents were experiencing potential exposure risk from rice ingestion,and appropriate measures should be taken to reduce the hazard.