Analysis of heavy metals in azadirachta indica a. Juss leaves, as bioindicator for monitoring enviromental pollution in guayaquil, ecuador

Abstract

In the Ecuadorian territory, there is no precise information of the air quality status. The only city that has an environmental monitoring network for certain pollutants is Quito, while in Guayaquil only atmospheric studies have been carried out between 1970 -1990 and 2003. Having a monitoring network in different cities is essential, but requires a lot of investment, it is for this reason that some countries have chosen to use plants as environmental bioindicators to assess the impact of a source of atmospheric pollution. Neem leaves can be used as bioindicators, bioaccumulators and biomonitors, due to their properties of accumulating high concentrations of metals. In the present study, heavy metals as Pb, As, Zn, Cd, Ni, Mn, Cr and Cu were analysed in leaves of Neem tree (Azaridachta indica A. Juss). The urban sampling areas selected were Plaza Colón, Av. Luis Vernaza and Loja, located in the city of Guayaquil-Ecuador. Spectrophotometric techniques as AAS and ICP were used for the determination of the metals on the leaves. The study demonstrated representative average concentrations for Zn> Cu> Mn> Ni> Cr in both sampling points. The values obtained for As, Pb and Cd were found below the limit of detection. These values indicated the existing environmental contamination in the selected urban areas due to vehicular traffic and demonstrate the efficacy of the Neem leaves as an environmental bioindicator.