Characteristics, source apportionment, and health risk assessment of pollution of heavy metals in plant foliar dust: characterization of atmospheric heavy metal pollution.

Plant foliar dust can be utilized as a passive sampler to characterize atmospheric heavy metal pollution level of a region. In this study, foliar dust samples were collected from the central urban area of Suqian, a key region for atmospheric pollution control in the Yangtze River Delta, China. The pollution characteristics, sources, and health risks of heavy metals were analyzed. The results revealed the following: The concentrations of Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb in foliar dust were 1.77, 1.25, 2.34, 6.41, 6.21, 1.39, 12.20, and 6.26 times higher, respectively, than the background values of soils in Suqian. Hotspots exhibited patchy spatial distribution patterns, primarily concentrated in public administration and service lands, as well as commercial areas. The EF values of Cd, Pb, Zn, and Cu were 9.7, 5.1, 5.1, and 5.0, respectively; the Igeo value of Cd was 2.9; the mean IIN was 2.2, reaching moderate pollution. Through the PMF model and Pearson correlation analysis, the fuel combustion (32.09%), mixed sources of traffic and construction dust (34.34%), industrial emissions (14.99%), as well as the combined source of agriculture, industry, and transportation (18.59%) were identified as the main sources. The HI value directly ingested by children through hand-to-mouth ingestion reached 1.8, and the carcinogenic risk of Cr via respiratory pathway fell within the range of 10-10, indicating potential health hazards that require careful management.