Trace metals are released into the environment via natural and anthropogenic processes. Metals such as Al, Mn, Fe, Cr, Ca²⁺ and K⁺ are indicative of soil contribution. The Earth’s crust is enriched with many of these elements and Aeolian dusts can efficiently transport some crustal elements and heavy metals. Non-crustal volatile metals, such as Cd, Zn, and Pb are characteristic of fuel combustion and metal smelting. The Central Analytical Laboratory (CAL) has come up with a method to measure low level concentrations in wet deposition samples via Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES).