Abstract:
Background Studies have shown that trace element selenium is associated with the development of many diseases such as cancer, cardiovascular disease, and acquired immune deficiency syndrome. Enshi Prefecture is a selenium-rich area in China, and the distribution of selenium is extremely uneven in different regions.
Objective This study aims to understand the selenium levels of staple crops, drinking water, and children's blood and hair in areas with different soil selenium levels in Enshi Prefecture, Hubei Province.
Methods According to the soil selenium levels reported in previous studies, Enshi Prefecture was divided into three areas with adequate (1.28-4.05 mg/kg), high (4.05-6.35 mg/kg), and extremely high (≥ 6.35 mg/kg) selenium levels, respectively. A town was randomly selected to collect samples from each area. From October to November 2016, five villages were selected from each town by plum sampling method, and six households were randomly selected from each village. Environment samples were collected from each area, including drinking water (n=90), potato (n=75), corn (n=74), and soybean (n=70). Three kindergartens were randomly selected from each area, and a total of 739 children aged 3-5 years were enrolled as study subjects. Venous blood samples (4 mL, n=443) and hair samples (0.1-0.2 g, n=739) were collected from the children. Selenium levels in the samples were measured by inductively coupled plasma mass spectrometry (ICP-MS).
Results The selenium concentrations of drinking water were (0.09±0.06), (1.72±3.61), and (3.15±2.05) μg/L in areas with adequate, high, and extremely high selenium levels in Enshi Prefecture, respectively (F=12.26, P < 0.001). There were differences in the selenium levels of corn and soybean among the three areas (F=9.43, 5.76, P < 0.01), highest in the extremely high selenium area, which were (0.31±0.39) and (1.36±2.47) μg/g, respectively. The children's blood selenium levels were (0.07±0.01), (0.11±0.04), and (0.08±0.03) mg/L in the adequate, high, and extremely high selenium areas, respectively, highest in the high selenium area, and their hair selenium levels were (0.46±0.21), (0.80±0.72), and (0.78±0.30) μg/g, respectively.
Conclusion Selenium distributions in drinking water, corn, and soybean vary by areas with different selenium levels in Enshi Prefecture. Children's selenium levels in this area are appropriate.