蘭陽平原農田土壤砷之分析

The Distribution of Arsenic in Cultivated Land in Lan-yang Plain

江漢全(Hann-Chyuan Chiang) ； 林智賢(Jyh-Shyan Lin)

《宜蘭技術學報》 9期工學專輯 (2002/12) Pp. 153-161

https://doi.org/10.6179/nit.bce.2002.09.24

摘要

砷為具有致癌性之有毒元素。本文彙整蘭陽平原土壤重金屬可能偏高地點及工業地區附近之農田土壤金屬含量調查資料，係於民國82年至民國86年間，共有6,525公頃522個樣品之調查分析，應用ArcView地理資訊系統的（GIS），探討砷在土壤中之分佈狀況，並以宜蘭市為案例，討論土壤砷含量分佈與地下水砷濃度間之關聯性。研究結果顯示，蘭陽平原表土砷含量達第四級標準（10-60 mg/kg）之面積，占所調查耕地面積之41.05%，裡土則為15.75%，表土與裡土砷含量平均值分別為10.49±5.30 mg/kg及10.81±5.05 mg/kg，差異不大，而以不同地點間差異較大。GIS可清楚顯示蘭陽平原農田土壤表土砷含量偏高之地區分佈於宜蘭市、壯圍鄉、員山鄉、羅東鎮、五結鄉及冬山鄉之部份村里；裡土砷含量偏高之地區則分佈於宜蘭市、壯圍鄉、五結鄉及冬山鄉之部份村里， 其分佈與工廠之座落點無關。以宜蘭市為案例，則顯示地下水砷濃度偏高與土壤中砷含量偏高之地點有顯著相關性。

關鍵字

土壤 ； 砷 ； 地理資訊系統

並列摘要

That arsenic can cause many types of human cancer is well known. In this study, 522 samples of 6525 ha cultivated land with higher potential of heavy metal pollution in Lan-Yang Plain were determined for arsenic content from 1993 to 1997. The results show that the average arsenic content in topsoils was 10.49±5.30 mg/kg and it was 10.81±5.05 mg/kg in subsoils. There were 41.05% of topsoil and 15.75% of subsoil samples belong to high grade (10-60 mg/kg) of arsenic. The distribution of arsenic in soils could be clearly demonstrated by ArcView geographic information systems (GIS). Among the ten counties of Lan-Yang Plain in this investigation, the high grade of As content in topsoils were found in part villages of I-Lan City, Chuang-Wei Hsiang, Yuan-Shan Hsian, Lo-Tong Chen, Wu-Chieh Hsiahg and Tung-Shan Hsiang. However, the high grade of As content in subsoils distribute over I-Lan City, Chuang-Wei Hsiang, Wu-Chieh Hsiang and Tung-Shan Hsiang. Moreover, a case study on I-Lan City shows that the relationship between arsenic content in soils and arsenic concentration in groundwater is significant.

並列關鍵字

soil ； arsenic ； geographic information systems