CADMIUM AND LEAD CONTAMINATION OF SOILS NEAR PLASTIC STABILIZING MATERIALS PRODUCING PLANTS IN NORTHERN TAIWAN

The Cd and Pb contamination in paddy soils and rice plants of northern Taiwan was caused by the stabilizing materials for plastics produced from two chemical plants. The content of Cd in the paddy soils, brown rice, surface water, and sediments on the polluted area (about 100 ha) are 0.22 to 1,486, 0.51 to 7.94, 0.01 to 50.0, 134 to 4,700-mu-g g-1, respectively. The content of Pb in the paddy soils, brown rice, surface water, and sediments on the polluted area are 6.3 to 12,740, 0.10 to 59.27, 0.12 to 3.59, and 23 to 44,427-mu-g g-1, respectively. Cadmium predominantly existed in the exchangeable and organic fractions in the polluted Udipsamment or Paleudult soils. Almost equal content (25 to 30% of total) of Pb existed in exchangeable, residual, and free oxides fractions in the polluted Udipsamment soils. A higher content of Pb existed in the residual fraction (48% of total) than that of the other soil fractions in the polluted Paleudult soils. Only trace amounts of Cd and Pb was absorbed by the brown rice. Correlation between concentration of Cd (or Pb) in the brown rice and contents of Cd (or Pb) in the polluted soils were not significant.