Soil lead and other metal levels in industrial, residential and nature reserve areas in Singapore

• Published in: Environmental monitoring and assessment 1997-02, Vol.44 (1/3), p.605-615
• Main Authors: Zhou, C.Y, Wong, M.K, Koh, L.L, Wee, Y.C
• Format: Article
• Language: English
• Subjects: Absorption; Acidic soils; Atomic absorption analysis; Atomic absorption spectroscopy; chemical digestion; Chromium; Digestion; Environmental monitoring; heavy metals; Industrial areas; Industrial pollution; Lead; Metal concentrations; mixed-level orthogonal array design; Nature reserves; Orthogonal arrays; polluted soils; Residential; Residential areas; Scientific imaging; Sediment samplers; Sediments; soil; Soil (material); soil analysis; Soil surfaces; Soils; Spectral analysis; Spectrometry; Surface chemistry; Surveys; Trace metals; Vehicle emissions
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1023/A:1005712519751

The use of pressure feedback microwave digestion technique has permitted rapid and efficient digestion of soil and sediment samples. The evaluation of different acid mixtures to digest soil samples were studied by mixed-level orthogonal array design. The selected acid mixture of HCl-HNO sub(3)-HF was employed in the survey of Pb, Zn, Cu, Cr and Mn in soil samples. Surface soil samples were collected from industrial, residential and nature reserve areas in Singapore. The five metal concentrations were determined by flame atomic absorption spectrometry and graphite furnace atomic absorption spectrometry. The lead and other metal contents in NBS SRM 1645, NIES CRM No. 2 and NRCC BCSS-1 sediment standard references were determined concurrently with the survey samples. Five measured metal loading on the surface soils was in the order: industrial area > residential area > nature reserve area. The trace metal concentrations in surface soil from areas of heavy traffic are higher than those from residential areas. The main sources of trace metal pollution are vehicular exhaust and industrial activities.