Regional and Global Scale Challenges for Controlling Arsenic Contamination in Agricultural Soil, Water Supplies, Foods and Ayurvedic Medicines

Arsenic is naturally present at high concentration levels in aquifers adversely affecting the life of some 200 million people in a number of countries on four continents. Human exposure to As from dietary sources such as marine fish, seafood, poultry, cereals is generally much lower compared to exposure through drinking contaminated water, using contaminated water in food preparation and irrigation of crops. Arsenic toxicity depends on its four valences [As(-III), As0, As(III) and As(V)] and chemical compounds. Thus, in seafood, As is mainly found in its less toxic organic forms. The qualitative and quantitative determinations of individual As species are crucial to understand the environmental fate and behavior of As. The aim of the present review is to give a brief overview on the main As speciation methods and to present how to control As contamination at local and global scales in several environmental (soil, waters) and biological (crops, basic and processed food) samples, as well as complementary and alternative medicinal products marketed as food supplements. In terms of chromatographic separation, emphasis is placed on separation by thin layer chromatography and solid phase extraction. Some approaches to address As contamination (e.g., stabilization in soil, provision of a safe water supply in affected communities) at global and regional scales are also presented.