ABSTRACT
Vanadium is an often-overlooked potentially toxic trace element; thus, most countries, whether in the developing or in the developed world, have not set up maximum regulation limits for its soil concentration, as it is the case for other elements. In this chapter we aimed to collect to the best of our knowledge all regulation limits of V of countries around the globe under one roof and present them in a comprehensive way. We also aimed to critique them as to whether they are sufficiently protective or unnecessarily relaxed. In order to achieve this goal, we followed the scenario that soil has the maximum allowable concentrations so that we may then assess the human health risk that may be induced under certain land uses and in different age groups, that is, adults and children. We found that legal limits are highly diverse in the few countries that regulate V and that limits of the same land uses are named with different terms; these two factors likely lead to confusion. As for the health risk assessment (HRA), we found that children in residential areas would have a hazard quotient of higher than unity (the threshold above which considerable risk is induced). We conclude that attempts should be made so that (a) countries and organizations with no current V regulation may be persuaded to set up limits, if contamination incidence occurs, a legal barrier to protect human health may already exist; (b) there is an attempt towards normalizing the highly diverse terms used in similar categories of soil regulations; and (c) certain countries, which have currently set up rather relaxed V limits for residential areas, should lower limit values, while limits for industrial zones and agricultural lands, which are currently unnecessarily overprotective, should be increased, as suggested by our analysis. Finally, we recognize that the HRA analysis we have followed here is based on probabilistic approaches, and thus our findings need to be further supported by evidence based on vital parameters now unaccounted for, that is, soil properties, climate and involved plant species.
