含銅、鋅、鉻及六價鉻土壤對蔬菜生長之影響

世界在這幾十年當中人口數逐漸上升，人類活動頻繁加上工業產業的快速及大量興起，如:電子產業、化學加工和電鍍等。而導致土壤、水及空氣等環境污染。其中土壤也受到重金屬污染，而此議題也成為全球關注的焦點。根據行政院環保署土壤及地下水污染整治基金管理會統計資料，至民國110年年底統計出全國重金屬污染列管之農地場址有一千餘公頃，這使農民種植作物帶來了困擾。蔬菜會吸收重金屬並將其沉積在可食用部位，通過人類攝取累積在體內而導致慢性病機率增加。為了使人類的健康及生命安全，已有許多可食用植物或蔬菜被當作土壤重金屬污染所研究的對象，如玉米及萵苣。本研究將選用兩種土壤分別為酸性屏科土壤及中性赤山巖土壤，再以人工配置的方式進行模擬試驗，分別加入含有重金屬鋅、銅、鉻及六價鉻溶液，濃度採用(1) 1/2農地監測標準；(2) 農地管制標準；(3) 一般管制標準；(4) 2倍一般管制標準。在這些受污染的土壤中種植三種作物，分別為小白菜、蜜雪兒白菜及青江菜來觀察蔬菜的發芽率與土壤之間的關係及蜜雪兒白菜的生長之情形，種植蜜雪兒白菜以拍照方式記錄，植體分析參考環檢所標準檢驗方法。結果顯示在濃度與發芽率的關係中，銅與鋅的表現非常相似，在屏科酸性受污染土壤的表現是濃度越高發芽率越少，在赤山巖中性受污染土壤濃度越高發芽率雖然有下降但較不顯著。六價鉻受污染土壤濃度與發芽率的表現，在屏科酸性土壤發芽率對濃度表現影響不大，但在赤山巖中性土壤中會隨著濃度越大發芽率越少。蜜雪兒白菜生長情形可之重金屬污染土壤濃度過大造成植物無法負荷時，移植幾天後就會死亡。而影響這些蔬菜發芽率與生長情況會依據土壤中重金屬濃度的不同導致影響植物對重金屬的毒性反應的不同、對植物在土壤中重金屬種類的不同影響其生長狀況和不同土壤性質影響植物對重金屬吸收有關。

關鍵字

蔬菜；重金屬；農地；蜜雪兒白菜

並列摘要

In the past few decades, the population of the world has gradually increased, and the frequent human activities and the rapid and large-scale rise of industrial industries have polluted the environment. The soil is also polluted by heavy metals, and this issue has become the focus of global attention. According to the statistics of the Soil and Groundwater Pollution Remediation Fund Management Board of the Environmental Protection Administration of the Executive Yuan, by the end of 2010, there were more than 1,000 hectares of agricultural land in the country with heavy metal contamination, which posed a problem for farmers in growing crops. Vegetables can absorb heavy metals and deposit them in edible parts, which can lead to increased risk of chronic diseases through human intake and accumulation in the body. For the health and safety of human life, many edible plants or vegetables have been studied for soil heavy metal contamination, such as corn and lettuce. The purpose of this study was to grow three kinds of vegetables in acidic soil and neutral soil with heavy metals in soil, and to observe the germination rate, growth situation and changes in the concentration of heavy metals in vegetables. In the soil contaminated with copper and zinc, the germination rate of neutral soil was better, while that of acid soil with chromium and hexavalent chromium was better. In the analysis of heavy metals in vegetables, when hexavalent chromium is 500 mg/kg, it cannot survive in terms of germination rate or plant growth. In summary, the germination rate and growth of these vegetables will be affected by the different concentrations of heavy metals in the soil, resulting in different toxic responses of plants to heavy metals, different types of heavy metals in the soil, and their growth conditions and soil properties. Plants absorb heavy metals.