Assessment of metals in PM10 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 PM10 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 PM10 filters and in Araucaria heterophylla needles using an Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The annual mean concentrations of PM10 ranged between 24.9 and 26.3 mu g m(-3), exceeding the limit established by the World Health Organization (20 mu g m(-3)). Statistical analyses, performed for the PM10 filters, showed that dust resuspension and anthropogenic activities were important sources for PM10 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 PM10 filters. This work not only improved scientific knowledge on the concentrations of PM10 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.

Automated summary

The reliability of Araucaria heterophylla needles as a biomonitor was assessed by analyzing metal concentrations in PM10 filters and the needles in the city of Quito, Ecuador. The study showed that natural emissions dominated the metal composition in both PM10 filters and needles, while anthropogenic emissions contributed to minor metals. The research not only provided insights into the concentrations of PM10 and metals in Quito, but also advanced the study on using Araucaria heterophylla needles as a biomonitor.