Contaminant emissions as indicators of chemical elements in the snow along a latitudinal gradient in southern Andes

Jaime Pizarro,Juan Alfonso,Pedro J Llanillo,Roberto Rondanelli,Francisco Fernandoy,Nicolas Huneeus,Steven Neshyba,Pablo M Vergara,Sergio Cerda,Ximena Castillo,Raúl R Cordero,Alessandro Damiani,Jorge Carrasco,Penny M Rowe,Fabrice Lambert,Gino Casassa

doi:10.1038/s41598-021-93895-1

Abstract

The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 μm and 10 μm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.

Highlights

Gaseous and particulate matter contaminants emitted from industrialized areas are dispersed in the atmosphere, reaching remote regions worldwide such as the poles and high-altitude m ountains[1,2,3]
Concentrations of Cu, Mn, Mg and Zn were positively associated to nitrogen oxide (NOx) emissions at 40 km, while NOx quantified at 50 km was associated to Zn only (Table S2; Table 3)
Air pollution from anthropogenic sources is an increasing environmental concern for mountain countries, which typically have developing economies based on the exploitation of natural resources and rapid natural to urban land conversion[38,39]

Summary

Introduction

Gaseous and particulate matter contaminants emitted from industrialized areas are dispersed in the atmosphere, reaching remote regions worldwide such as the poles and high-altitude m ountains[1,2,3]. These atmospheric particles act as dispersal vectors for elements, many of them potentially toxic to plants and animals, with a fraction of them being eventually deposited upon snow[4]. To date no study has assessed the importance of atmospheric emissions in explaining the concentration of elements in high-mountain snow of central and southern Andes. We aim at assessing the relationship between air pollution and the concentrations of chemical elements along the central and southern Andean range, a ca. 3000‐km north–south gradient

Methods

Results

Conclusion