Migration Characteristics,the Pollution Sources And Health Risk Of Heavy Metals In Farmland Soils From Xiamen

In this paper,the profile soils of different agricultural functional areas in Xiamen are used as research objects.Soil samples,including 1 dryland profile soil,2 vegetable garden profile soils,2 paddy field profile soils,and 2 tea garden profile soils(profile 1 and profile 2)were collected.In order to know about the distribution of heavy metals in profile soil,concentrations,chemical speciation of heavy metals have been determined.Multivariate statistics,Pb and Sr isotopes and quantitative health risk methods were used to reveal the migration and health risks of heavy metals.The main conclusions were as follows:Migration coefficient results showed that the migration characteristics of heavy metals in paddy field was the most obvious,which may be related to its farming method.The results of leaching showed that the leaching down of each element was the most obvious in paddy.The significant differences of various chemical speciation of Pb isotopes in different soil layers from different agricultural areas.The weak acid dissolvable heavy metals content in 0-50 cm soil layer of a vegetable garden in Jimei District.The F1 and F3 state of Pb contents in a vegetable garden soil from Tong'an District were artificially disturbed to some extent.In the 0-60 cm layer of a paddy field in Tong'an District,the weak acid dissolvable might be derived from atmospheric dust and tire source.The chemical forms of Pb in profile soil 1 and soil 2 of the tea garden mainly originated from the parent material.Sr was mainly from the parent material of vegetable garden in Tong'an district.The Sr in the surface layer was from human activities in the paddy field of Jimei District,and in the remaining soil layers of Sr were mainly originated from the parent material.In Tong'an District of paddy field of the Sr were mainly from the parent material.The result of the health risk quantification showed that the traffic emissions was major risk source for adults in the vegetable garden of Jimei District,and the non-carcinogenic risk contribution rate was 82.99% for mixed source in paddy field.In the tea garden profile 1,the contribution value of the mixed source was 89.16%.In Tong'an of vegetable garden soils,the mixed source(agricultural activities and transportation emissions)was the most risk source to population.The rate of health risks for traffic sources in paddy field and tea garden profile 2 in Tong'an District was the most contribution.As for the carcinogenic risk,the contribution rate of carcinogenic risk for parent material was 60.27% in the vegetable garden of Jimei District.The agricultural activities had most contribution of carcinogenic risk in paddy soil of Jimei District.And in tea garden profile soil 1,the highest contribution of carcinogenic risk for adults was agricultural activities(69.02%).The main carcinogenic risk source of heavy metals was mixed source(agricultural activities and traffic emissions)in vegetable garden soil of Tong'an District.The mixed source(agricultural activities and traffic emissions)was the main source of paddy field in Tong'an District.The influence of external sources for the risks in tea plantation profile 2 was not significant.