Environmental pollution, strictly interconnected to industrial spread, started in the most advanced countries. It is now diffused all over the world with a significant predominance in the emerging industrialized states. Varying factors contribute to the location of a large number of "potential polluting" industries in these countries due to the quite recent industrialization: source of raw materials (mines, forests, . ), water availability, ready availability of manpower and its lower incidence on cost, laws not yet as restrictive as in advanced industrial countries. Actually, most raw matter is treated locally, not only for their natural resources, but also because of the lower cost of preliminary treatments. These treatments are the most hazardous, the heaviest and above all the most polluting.

In order to have a clear picture of the main anthropogenic sources of metal, or better said toxic element in general, pollution and their health effects, the sources, uses, correlated health disorders, and suggested concentration limits are reported in the following sections for each main polluting toxic element.