EPA-91-H103-02-214

091

860 千元

2002/03/15

2002/12/14

於幼華

土污基管會

國立台灣大學環境工程學研究所

土壤及地下水

物質流、風險評估、鎘、重金屬

material flow, risk assessment, cadmium, heavy metal

馬鴻文

鎘為毒性化學物質，流布在環境中會造成極大傷害。台灣是一個新興經濟工業國家，舉凡塑膠、金屬加工、以及電子產業，都是世界最大製造或代工產地之一，但這些行業也使用含鎘物質，並透過各種污染物經由不同媒介，可能威脅到當地人體健康及生活環境。台灣先後在桃園縣、台北縣、彰化縣、雲林縣、台中縣發生農地土壤污染鎘污染事件。工廠排放含鎘廢水至灌溉渠道中，經農民長期引用這些廢水灌後使得稻米鎘含量過高，造成當地130餘公頃污染農田並導致鎘米事件。本研究以鎘為例，以物質流(Material Flow Analysis，MFA)為分析工具，研究鎘在台灣的流向與流量，並以風險評估方法( CalTOX Model )探討台灣居民暴露的風險，以做為行政院環保署制定更有效的鎘物質管理政策，減少鎘的危害。研究結果發現，2000年存在台灣環境的鎘約共679.89公噸，其中鎳鎘電池396.95公噸(58%)，塑膠251.50公噸(37%)，鉛／鋅15.97公噸(2%)，石灰及石膏6.14公噸(1%)，煤4.58公噸，鋼鐵3.90公噸，含磷肥料0.36公噸。經過消費使用後，共有166.74公噸進入廢棄物處理系統，焚化爐燃燒後灰燼含鎘量有34.56公噸，焚化過程中排入空氣有1.82公噸，掩埋有128.56公噸，回收再利用有1.8公噸。以台灣地區平均22個縣市之資料經過加權統計後的平均調查濃度，發現以雲林縣、彰化縣致癌風險為最高(2.56903×10-9~3.50741×10-7)，此風險值已經非常接近臨界值(10-6)。在非致癌風險方面，雖然也是以高雄縣和雲林縣為最高，但最低的縣市為新竹縣、市。不過所有地區的非致癌風險值（危害商數），在進行風險管理前，都已經超過最低標準數值1，然而在政府進行休耕措施及地下水的禁用上，非致癌風險將可以的有效被控制，數值最高的雲林縣也都控制在0.1，遠在可能會造成危害的數值1之下。

物質流、風險評估、鎘、重金屬

0000023543.zip

22MB

[期末報告]公開完整版

2014/10/31 下午 02:07:46

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

material flow, risk assessment, cadmium, heavy metal