海南岛生态环境中的硒

生态环境中硒含量异常直接影响人体健康。海南岛生态环境中,土壤全硒量为0.043～0.785ppm。土壤硒含量有明显地理分异,东北部和东部较高,西南部和平原地区较低。生物气候对硒的地理分异有显著影响。本岛河水含硒量为0.10～1.85ppb,植物含硒量大多是0.05～0.20ppm,均属正常范围。另外,生态环境中硒含量也受土壤生物地球化学过程的影响。

Selenium in the Ecological Environment of Hainan Island

Selenium is an important trace element which is essential to animals andhuman beings, but may be harmfur when its content in the ecological environment goes beyond the mormal level. The content of Se in the ecological environment is controlled by a series of factors such as soil, water and plant. The Se content in soils of Hainan ranges from 0.043 to 0.785ppm, which mostly depends on biotic climatic conditions. In the upper layer of soil, Se often adheres to and is fixed by humus, especially by fulvic acid. Se also adheres to clay mineral. The water soluble Se content in soils of Hainan ranges from 3.50 to 20.50ppb. HSeO_3~-can combine with Fe(OH)_3, froming insoluble compound Fe_2(OH)_4SeO_3, and this leads to a lower soluble Se content. Selenium content in the water environment of Hainan ranges from 0. 8 to 1. 85 ppb. Se content in plants of Hainan ranges from 0. 021 to 0. 319ppm, which is related to plant properfies, water soluble Secontent, and other factors.