自動車 排氣가수에 包含된 鉛化合物의 排出에 의하여 汚染이 되었을 것으로 豫想되는 大邱直轄市를 中心으로 慶尙北道 內의 高速道路 및 主要國道邊에 隣接한 18個 地點을 選定하여 道路로부터 距離에 따른 畓土壤에서 鉛汚染度 및 土壤中 鉛化合物을 KNO₃浸出性(置換態), Na₄P₂O_7 浸出性(有機態), EDTA 浸出性(炭酸態) NHO₃ 浸出性(黃酸態), 非浸出性(不溶態)로 形態別 分布를 調査한 結果는 다음과 같다. 1. 畓土壤中 平均 鉛含量은 淸道에서 30.0 ppm으로 가장 높았고 高靈에서 14.8 ppm으로 가장 낮았으며 平均 21.9 ppm 으로 나타났으며, 交通量과 關聯하여 土壤中 鉛含量은 差異를 發見할 수 없었으나 道路의 開通年度에 따라 약간의 差異를 나타났다. 2. 道路로부터의 距離에 따른 鉛含量은 10m 以內에서 22.2 ppm, 10∼30m에서 22.1 ppm, 30∼50m에서 22.2 ppm, 50m 以上 地域에서 21.3 ppm으로 道路로부터 距離에 따른 畓土壤中의 鉛汚染度는 크게 差異 나지 않았다. 3. 土壤中 鉛化合物을 形態別로 分別 抽出한 結果 여러 가지 土壤特性에 따라 差異가 深하나 18個 地點에서 平均한 鉛化合物의 化學的 形態別 分布比는 有機態 33.6%, 炭酸態 29.8%, 黃酸態 21.5%, 置換態 8.6% 및 不溶態 6.7%의 順으로 나타났다. 4. 土壤中 有機物含量이 增加할수록 有機態 鉛의 分布比는 增加하는 傾向을 나타낸 반면 置換態 鉛의 分布比는 減少하는 傾向을 나타내었다. 5. CEC가 增加할수록 有機態의 鉛의 分布比는 增加하는 傾向을 나타낸 반면 置換態 鉛의 分布比는 減少하는 傾向을 나타내었으며, CEC에 依한 土壤中 鉛化合物의 化學的 形態別 分布比는 有機物에 依한 分布比와 비슷한 傾向을 나타내었다.

The object of this stduy was to investigate the pollution of Pb in paddy field soil with different distance from roadside and to find out the relationship between the ratio of chemical fractions of total Pb and soil characteristics. Lead from automobiles is exhausted as particulates composed primarily of halide compounds (PbBrCl, PbBr₂, PbCl₂). The samples of soil were collected directly from the paddy fields with different distance from the roadside of highway and expressway which are located in Kyungpook province. A sequential extraction procedure was used to fractionate Pb in paddy field soil into the disignated forms of water soluable, exchangeable, organically bounded, carbonate, sulfide, and residual Pb. Results obtained are summerized as follows. 1. The content of Pb in paddy field soil was the highest in Chungdo, 30.0 ppm, the lowest in Koryung, 14.8 ppm, and the total average content was 21.9 ppm. The effect of traffic volume was not clear, but a slight difference according to the order of opened year of roads was showed. 2. The effect of distance from roadside was not clear. The content of Pb in paddy field soil with different distance from roadside was 22.2 ppm within l0m, 22.1 ppm in 10∼30m, 22.2 ppm in 30∼50m. and 21.3 ppm beyond 50m. 3. The distribution of Pb fractions in soil showed a wide difference depending on soil properties. The average content of exchangeable. organically bounded, carbonate, sulfide, and residual Pb was 8.6%, 33.6%, 29.8%, 21.5%, and 6.7%, of total Pb in the soil, respectively. 4. The content of organically bounded Pb in soil showed highly positive correlation with organic matter and CEC, while the content of exchangeable Pb was highly negative correlation. 5. With higher soil organic matter and CEC, organically bounded Pb fraction tend to be higher but exchangeable Pb fraction tend to be lower. Other forms of Pb showed no difference with soil organic matter contend and CEC. The distribution of Pb fraction related to CEC showed similiar tendency with that of organic matter content.