Health risk of heavy metal exposure from dustfall and source apportionment with the PCA-MLR model: A case study in the Ebinur Lake Basin, China

Abstract

A comprehensive understanding of the characteristics, sources and risks of heavy metal pollution in urban atmospheric dustfall is the basis for environmental prevention and policy formulation. In this study, spatiotemporal distribution characteristics were investigated by analyzing the dustfall fluxes and heavy metal contents in six cities of the Ebinur Lake Basin during heating (Winter) and nonheating (Summer) periods. The possible sources with impact potential on human activities were identified using the principal component model analysis and multiple linear regression (PCA-MLR), so the human health risk of heavy metal exposure to dustfall was assessed. The result revealed that the atmospheric dust flux in the nonheating period was higher than that in the heating period. Temporally, the concentrations of all heavy metals except Cd and Pb in atmospheric dustfall were higher in the heating period than in the nonheating period. Half of the heavy metals have spatial distribution variations. Cr, As and Pb show both carcinogenic and noncarcinogenic risks to the human body, and the carcinogenic risk of Cr exceeds the maximum acceptable level by more than ten times. Source apportionment analysis showed that heavy metals in the atmospheric dust of the Ebinur Lake Basin mainly came from fuel combustion and soil dust during the nonheating period, followed by industrial dust sources and traffic sources, while in the heating period, heavy metals mainly came from the various sources of both soil dust and building material dust, followed by industrial activities such as coal combustion, industrial dust and automobile exhaust. The results of the study will provide useful insights into dustfall source apportionment and provide a basis for decision-making in regional air pollution control.