Assessment of airborne metal pollution in urban parks and industrial areas using Callistemon citrinus and Acacia melanoxylon

Abstract

Trees have been considered an effective means of assessing metal pollution in urban areas. In the present work, Callistemon citrininus and Acacia melanoxylon leaves were used to assess the air quality in urban parks surrounded by high vehicular traffic and in areas of industrial activity. The concentration of metals (Ca, K, Mg, Fe, Al, Mn, Ba, B, Zn, Cu and Pb) in the leaves was determined, and the results were compared between tree species and site types (parks and industrial). Ca, K, and Mg were found in higher concentrations than the other metals. Although significant differences in the concentration of metals between both tree species only reflected the composition of the plant itself, Acacia melanoxylon seems to display better performance as a biomonitor. According to the contamination factor (CF) results, most of the sites were classified as having suspected, slight or moderate contamination. Moreover, CF and principal component analysis indicated that Cu, Zn, Fe and Al were found to be the most contaminating metals at industrial sites, while Cu, Pb, Ba and Mn were the most contaminating metals at park sites.