WANG Weixing, CAO Shuping, ZHANG Yana, LI Gongke

(Tianjin Institute of Geological Survey, Tianjin 300191, China)

Abstract: Iodine is one of the essential trace elements of human, but too high or too low content of iodine in the human body may cause various diseases. The paper studied geochemical characteristics and causes of iodine in soil and water environments of eastern Tianjin. The results showed that the iodine content in surface soil was between 0.89 mg/kg and 17.09 mg/kg, with an average of 5.11 mg/kg, which was 1.92 times of its background value of Tianjin or 1.36 times of the national background value. The iodine content in deep soil ranged from 0.64 mg/kg to 34.55 mg/kg, with an average of 10.73 mg/kg, which was 3.93 times of the benchmark value of deep soil or 2.1 times of the value of surface soil in the study area. The surface and deep soils of the study area showed enrichments of iodine. The area of surface soil with high iodine background is large, distributed mainly in Dongli district, southern Ninghe district and northern Binhai new district. The iodine content of shallow groundwater ranged from 0.03 mg/L to 4.00 mg/L, with an average of 0.56 mg/L. The area of groundwater with high iodine content is also large, distributed mainly in Dongli district, Jinnan district, southern Ninghe district and Binhai new district (except of the southwest region). Historically, the study area was a strong land-sea interaction zone and enriched a large amount of iodine supplied by seawater, which could result in the overall high iodine contents in soil and water environments of the study area.

Keywords: Tianjin；iodine；geochemistry；genesis

EARTH AND ENVIRONMENT Vol.48, No.3, Tot No.335, 2020, Page 327-331