Comparación de dos métodos empleados para la determinación de material particulado depositado en la superficie de especies vegetales

Abstract

Vegetation acts as a biological filter retaining particles on its surface. It provides an ecosystem service, which allows to improve air quality, mostly in urban and industrial areas, where occasionally particulate matter (PM) exceeds permissible limits. PM affects health in such ways as respiratory diseases, cardiovascular diseases and even cancer. Therefore, alternatives have been sought to reduce their concentrations in environmental air. Vegetation can improve air quality by capturing and retaining PM on its surface. The large foliar area of trees, makes them the most effective type of vegetation for that purpose. At the same time, small leaves and complex shapes increase efficiency. Several methods have been developed to comprehend the capacity of the vegetation to remove and quantify PM. The aim of this study was to evaluate the degree of agreement between two methods: water cleaning and brush cleaning on the leaf surfaces. For this purpose, large, coarse and fine fractions of PM were estimated by both methods, on the leaf surface of two tree species of the same family, Salicaceae, but with different characteristics, Salix humboldtiana and Populus balsamifera. For each species, 10 samples were collected, with a subsequent replication. The degree of concordance was estimated using the Lin’s concordance correlation coefficient (CCC). In addition, the absolute error was calculated as well. No statistically significant differences were found in the accumulation capacities between species. Results show a poor degree of agreement between the methods (< 0,90), corroborated by relative error values between 29,18 % and 195,79 %. In this way, the brush cleaning method cannot replace the water cleaning method. Nonetheless, as new research highlights, these methods must be complemented to ensure a greater efficiency of PM quantification.