The study of metal contamination in urban soils of Hong Kong using a GIS-based approach

• Published in: Environmental pollution (1987) 2004-05, Vol.129 (1), p.113-124
• Main Authors: Li, Xiangdong, Lee, Siu-lan, Wong, Sze-chung, Shi, Wenzhong, Thornton, Iain
• Format: Article
• Language: English
• Subjects: Applied sciences; Automobiles; Chromium; City Planning - methods; Cluster Analysis; Contaminants; Contamination; Copper; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Monitoring - methods; Exact sciences and technology; Geochemistry; Geographic Information Systems; GIS; Heavy metals; Hong Kong; Industrial buildings; Industry; Isotopes; Isotopes - analysis; Lead (metal); Metals, Heavy - analysis; Monitoring; Nickel; Pb isotope; Pollutants; Pollution; Pollution sources. Measurement results; Pollution, environment geology; Principal Component Analysis - methods; Roads; Sampling; Satellite navigation systems; Soil and sediments pollution; Soil Pollutants - analysis; Urban areas; Urban soil; Zinc
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2003.09.030

The study of regional variations and the anthropogenic contamination by metals of soils is very important for environmental planning and monitoring in urban areas. An extensive survey was conducted in the highly urbanized Kowloon area (46.9 km2) of Hong Kong, using a systematic sampling strategy with a sampling density of 3–5 composite soil samples (0–15 cm) per km2. Geochemical maps of ‘total’ metals (Cd, Cr, Cu, Ni, Pb and Zn) from strong acid extraction in the surface soils were produced based on geographical information system (GIS) technology. A significant spatial relationship was found for Ni, Cu, Pb and Zn in the soils using a GIS-based analysis, suggesting that these metal contaminants in the soils of the Kowloon area had common sources. Several hot-spot areas of metal contamination were identified from the composite metal geochemical map, mainly in the old industrial and residential areas. A further GIS analysis revealed that road junctions, major roads and industrial buildings were possible sources of heavy metals in the urban soils. The Pb isotope composition of the contaminated soils showed clear anthropogenic origins. GIS can be used to identify soil contamination hot-spot areas and to assess potential pollutant sources in an urban community.