Assessment of Anthropogenic Volatile Organic Compounds in Leaves of Two Urban Tree Species in Santiago de Chile

Abstract

Anthropogenic volatile organic compounds (AVOCs) represent the third largest contribution in gaseous emissions in the urban and peri-urban region of Santiago, the capital of Chile. Some of these compounds are toxic or mutagenic, cause serious damage to human health, and decrease plant growth and development. There is little international information related to atmospheric AVOCs in leaf content from trees exposed to specific sources of pollution, and to our knowledge, there is no research on this topic in Chile. The purpose of this work was to study the leaf content of AVOCs from the Organic Range of Gasoline (ORG: range 6-10 C) emitted by local traffic during the austral summer and spring seasons in leaves of two exotic tree species (Liriodendron tulipifera and Platanus × acerifolia). Leaf samples collected around 2 meters height above the ground were pulverized with a cryogenic mill and eleven chemical components were quantified (toluene, 1,2,4-trimethylbenzene (1,2,4-TMB), styrene, ethylbenzene, ortho, meta and para-xylenes, naphthalene, 1,3,5-trimethylbenzene (1,3,5-TMB), isopropylbenzene, and trichloroethene) using GC-MSD MSD. Benzene was detected but not quantified, because it was always under the quantification limit of the technique. Differences in concentrations were found for type of site exposure, season and tree species. The differences found in leaf content of AVOCs in P. × acerifolia exposed to vehicle traffic suggest that the concentration of these contaminants in leaves may be due to AVOC capturing. Considering the content of AVOCs in leaves and not in the whole individual tree, L. tulipifera presented a higher concentration of total AVOCs than P. × acerifolia for both seasons. The Prop-Equiv and OFP of L. tulipifera were very high in summer, being 13.6 and 14.8 times greater, respectively, than the corresponding values for P. × acerifolia.

Magnetic and elemental characterization of the particulate matter deposited on leaves of urban trees in Santiago, Chile

“…However, there is growing evidence that the removal of PM is one of the positive effects of urban forests (Dzierzanowski et al, 2011;Manes et al, 2016;Nowak et al, 2018;Song et al, 2015), among other effects such as providing primary productivity of vegetation (Costanza et al, 2007;Roeland et al, 2019) or removing gases (Araya et al, 2019;Nowak et al, 2018;Viecco et al 2018). Indeed, the leaves' surface and stems adsorb or absorb significant amounts of air pollutants.…”