Characteristics, causes and ecological environment health evaluation of Selenium-enriched soil in Gaocheng District of Shijiazhuang City, Hebei Province

Selenium has an important impact on human health. This paper takes Gaocheng as a research object to test and analyze the content of selenium and heavy metal elements in different media in the study area with HG-AFS and ICP-MS method. Based on the discussing of the characteristics, main causes and sources of selenium content in soil, the health of the local ecological environment is evaluated. The results show that the average selenium in the surface soil of Gaocheng is 0.32mg/kg, and the enrichment coefficient reaches 1.68, which is generally higher in the southern part of the study area, about 171.12 km² reaching the standard of selenium-rich soil. The selenium enrichment in soil is mainly caused by human beings, and its main sources are coal burning and irrigation water. The selenium content of agricultural products in the selenium-rich area is much higher than that in the non-selenium-rich area, part of which meets the natural selenium-rich food standard. The selenium intake of residents is about 123.47 mg/d, which is at a reasonable level. The heavy metal pollution degree is Cd> Hg> Pb> Cu> Zn> Ni> As. The ecological risk assessmen of a single heavy metal t shows that Cd and Hg are the main hazard elements, and the other heavy metal potential risks are low. The human health risk assessment of heavy metals indicates that the non-carcinogenic and carcinogenic risk indexes in the study area are within a safe range, and oral intake is a source of health. Children are more vulnerable to oral intake than adults.