Assessment of metals in PM(10) filters and Araucaria heterophylla needles in two areas of Quito, Ecuador

The reliability of Araucaria heterophylla needles as a biomonitor was evaluated by analyzing the concentration of metals in PM(10) filters and in Araucaria heterophylla needles. The sampling campaign was carried out at two sites in the city of Quito, Ecuador, in 2017–2019. Concentrations of Cr, Cu, K, Mn, Pb, Zn, Ca, Fe, Al and Mg were determined in PM(10) filters and in Araucaria heterophylla needles using an Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES). The annual mean concentrations of PM(10) ranged between 24.9 and 26.3 μg m(−3), exceeding the limit established by the World Health Organization (20 μg m(−3)). Statistical analyses, performed for the PM(10) filters, showed that dust resuspension and anthropogenic activities were important sources for PM(10) emissions in the city. Metals related to natural emissions (Ca, Mg, K, Al and Fe) dominated in both types of samples, while the minor metals were those related to anthropogenic emissions (Zn, Cu, Cr and Pb). The former were positively associated with the needle samples, while the latter were associated with PM(10) filters. This work not only improved scientific knowledge on the concentrations of PM(10) and metals in the Andean city of Quito, but also greatly contributed to the progress of research on the use of Araucaria heterophylla needles as a biomonitor.