| 英文摘要 |
Cadmium is a toxic chemical, whose flow in the environment may impose great hazards. As a newly developed industrial country, Taiwan hosts the biggest manufacture or OEM bases in the world for industries such as plastics, metal processing and electronics. These industries employ a large amount of cadmium containing materials, and the pollutants they produced affect the health and living environment of local population through various media.
Episodes of cadmium contamination in farmland occurred at various times in Taoyuan, Taipei, Changhua, Yunlin, and Taichung Counties in Taiwan. Manufacturing plants discharged cadmium-containing wastewater into irrigation canals long used by rice farmers. This led to the contamination of more than 130 hectares of rice paddy and produced rice with high cadmium content, which is so called “Cadmium Rice Accident.”
This study applied Material Flow Analysis (MFA) on cadmium to investigate its distribution and amount in Taiwan. In addition, risk assessment (CalTOX Model) was conducted to assess the exposure risk of people in Taiwan. The objective of this study is to provide information to enable the environmental authorities to stipulate more effective regulation policy on cadmium and thereby minimize the hazards it imposes.
This study found there was 679.89 tons of cadmium in Taiwan in 2000, among which 396.95 tons of nickel-cadmium batteries (58%), 251.50 tons of plastics (37%), 15.97 tons of lead/zinc (2%), 6.14 tons of lime and gypsum (1%), 4.58 tons of coal, 3.90 tons of iron and steel, and 0.36 ton of phosphorus-containing fertilizers. After consumption, a total of 166.74 tons went into the waste treatment system. 34.56 tons of cadmium appeared in the ash after incineration and 1.82 tons were emitted into the air during the incineration process, 128.56 tons were landfilled and 1.8 tons recycled.
Based on the weighted average concentration data of 22 counties/cities in Taiwan, it was found that carcinogenic risk was h
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