About the book
Nature has slow occurring biogeochemical cycles of trace elements and heavy metals and the cycles have significantly controlled the environmental fates of these elements. The trace elements and heavy metals cannot be degraded like organic pollutants and they may transform and become stable and persistent contaminants that accumulate in soil and sediments. With industrialization, great amounts of trace elements and heavy metals have been excavated and released on the surface of the earth and dissipated into the environments. Heavy metals are potent free radicals and disrupters of human health. Heavy metals include antimony, arsenic, bismuth, cadmium, cerium, chromium, cobalt, copper, gallium, gold, iron, lead, manganese, mercury, nickel, platinum, silver, tellurium, thallium, tin, uranium, vanadium, and zinc. Trace elements occur in natural environments ubiquitously in small amounts and when present in sufficient bioavailable concentrations, they are toxic to living organisms. They occur as ions compounds, complexes, and adsorbed/precipitated/co-precipitated on mineral surfaces. Human activities have drastically altered the biogeochemical cycles and equilibria of these trace metals in the ecosystems.
Trace elements enter the ecosystems via direct discharges from industrialization processes, sewage sludge, atmospheric deposits, and agricultural practices including the application of pesticides or fertilizers. They can be transferred from sediments to benthic organisms and then become a potential risk to human consumers through the food chain. We have a system of X-ray emission techniques, Energy Dispersive X-ray Fluorescence, and Proton Induced X-ray Emission, in which we have detected trace elements (micronutrients as well as toxic elements) which can be useful as well as harmful to the human consumption.