Toxic Metals in Road Dust from Urban Industrial Complexes: Seasonal Distribution, Bioaccessibility and Integrated...

Area of Science:

• Environmental Science
• Toxicology
• Urban Ecology

Background:

• Urban industrial expansion reduces spatial separation, increasing road dust contamination.
• Road dust contains toxic metals posing human health risks via inhalation, ingestion, and contact.
• Understanding seasonal patterns and bioaccessibility of metals in urban dust is vital for risk assessment.

Purpose of the Study:

• To investigate seasonal patterns, bioaccessibility, and human health risks of toxic metals in Wuhan's urban road dust.
• To assess concentrations of Cadmium (Cd), Nickel (Ni), Arsenic (As), Lead (Pb), Zinc (Zn), Copper (Cu), and Chromium (Cr).
• To develop an improved health risk assessment model integrating metal enrichment, bioaccessibility, and uncertainty.

Main Methods:

• Collection of 34 dust samples from roads near industrial facilities in Wuhan's Qingshan District.
• Analysis of toxic metal concentrations and comparison with national standards (GB 15618-2018).
• Application of the Simplified Bioaccessibility Extraction Test (SBET) and an improved health risk assessment model.

Main Results:

• Ni and As concentrations exceeded national limits; Cd, Pb, and Cu were within limits.
• Higher concentrations of Ni, As, Pb, Zn, and Cr were observed in summer.
• Cd and As posed significant carcinogenic risks to children, identified as priority control metals.

Conclusions:

• Urban road dust in Wuhan is contaminated with toxic metals, with seasonal variations.
• Cadmium (Cd) and Arsenic (As) are priority metals for control due to carcinogenic risks in children.
• Periodic monitoring and regulation of As and Cd emission sources are recommended, particularly during winter and spring.