Geochemical Elements That Plants Absorb from Soil and Water

In this chapter, we discuss three chemical elements – arsenic, selenium, and fluorine – that occur in the environment after leaching from rocks and minerals. Animals need these elements in small amounts for normal life. Humans need adequate amounts of selenium and fluorine, while the necessity for arsenic has not yet been proven. However, compounds of arsenic have been used for centuries as means of intentional poisoning and as pesticides. Plants growing in the wild or grown for food or animal feed are able to absorb from the soil and concentrate various compounds, some of which can be toxic to plant eaters. Groundwater used for drinking or cooking may also contain large amounts of toxic elements from the lithosphere.