CHANGES IN THE INORGANIC ELEMENT CONCENTRATION SPECTRUM OF MESQUITE FOLIAGE DURING OPERATIONAL AND NON-OPERATIONAL PERIODS OF A COPPER SMELTER

Leaves of honey mesquite (Prosopis julifora) were collected along dist ance and elevation gradients from an Arizona copper smelter during a y ear of smelter operations and during a year of a smelter shut-down. An inorganic leaf element concentration spectrum for elements Zn, Cu, Fe , Ti, Mn, Al, Mg, Cs, Sm, U, Yb, As, La, Hf, Sb, Sc, V, In, W, Ba, Br, K, Na and Cl was derived for both sampling periods. Sources of elemen t origin were identified through factor analysis and correlation matri ces, Elements Cu, As, Sb, W and In, which are emitted in significant q uantities during the smelting process and are good smelter pollution t race elements, were reduce up to 95% in mesquite leaves collected afte r the smelter shut-down. Leaves grown in the smelter vicinity during s melter operations showed visible leaflet deformation while no leaf dam age was observed on the same trees during the non-operational period. The seasonal change in mesquite leaf element concentrations could be d irectly related to the seasonal change in atmospheric smelter pollutio n.