Contamination characteristics of heavy metals in particle size fractions from street dust from an industrial city, Central China

Abstract

In order to investigate the heavy metal pollution level and distribution characteristics in different particle sizes, and to evaluate the health risk, 42 street dust samples were collected in January 2015 from Huangshi, as an industrial city in Central China. The results analyzed by flame atomic absorption spectrometry (FAAS) showed that the average content of Cu, Pb, Zn, Cd, Mn, and Fe in the fine particle diameter (< 25 μm) was 1041.12, 361.64, 890.00, 14.43, 3178.52, and 61841.79 mg kg−1, respectively. Meanwhile, the average content of Cu, Pb, Zn, Cd, Mn, and Fe in the coarse particle diameter (25 < D < 75 μm) was 1628.54, 401.52, 593.16, 9.54, 5316.07, and 76765.37 mg kg−1, respectively. Compared with other cities, the heavy metal pollution of street dust in Huangshi was more serious. The results indicated that heavy metals were more easily enriched in fine grains street dust, except for Cu, Mn, and Fe. The heavy metal elements showed obvious spatial heterogeneity in different regions, and the interference from human sources was greater. Heavy metals in Huangshi street dust are generally at moderate or higher pollution levels (except Fe), of which Cu and Cd are the most seriously polluted. Multivariate statistical analysis shows that the heavy metals in fine-grained street dust mainly come from traffic/industrial mixed sources (74.5%) and industrial sources (25.5%); the heavy-grained street dust heavy metals mainly come from mixed traffic/industrial sources (55.1%) and soil source (44.9%). For non-carcinogenic heavy metals, mainly through the hand-mouth contact pathway into the human body, there are also no non-carcinogenic health risks in both hand-mouth ingestion and dermal contact. For carcinogenic heavy metals, Cd in street dust did not have carcinogenic risk.