2000年二仁溪整治後魚類肌肉及肝臟中重金屬濃度的比較   全文下載

Comparison of the Metal Concentrations in Muscle and Liver Tissues of Fishes from the Erren River, Southwestern Taiwan, after the Restoration in 2000

本研究是以魚體肌肉及肝臟中重金屬的蓄積濃度來暸解二仁溪自2000年進行整治計劃後的重金屬污染現況，同時首次報告此區域魚體中鐵、錳、砷與汞的測值，以建立基礎背景值做為未來後續監測比較之用。採樣工作於2002年1月在污染最嚴重的三爺宮溪與二仁溪交會處附近進行，共採集大眼海鰱、虱目魚、大鱗?、烏魚與吳郭魚等五種魚類91尾，經解剖取其肌肉與肝臟組織後，進行必需元素鐵、鋅、銅、錳與毒性元素砷、汞、鎘等共七種元素之分析，所得數據皆以mg／kg 濕重表示。結果顯示，重金屬蓄積濃度以鐵、鋅最高，銅、錳、砷次之，而汞及鎘則最低。組織間的差異，則除砷和汞外，皆以肝臟的濃度高於肌肉。無論魚肝或魚肉皆依元素的不同而存在顯著的種間差異（p < 0.05）。魚肉中鐵、鋅、銅與錳的最高含量分別出現在吳郭魚（4.04）、烏魚（4.38）、大鱗?（0.20）與虱目魚（0.534），而毒性元素砷與汞的含量分別以烏魚（1.59 ）和大眼海鰱（0.081）為最高。魚體肝臟中鐵、汞和鎘的最高濃度皆出現在大鱗?（鐵 = 3122、汞 = 0.045和鎘 = 0.123,），另外，魚肝中鋅、銅與砷的最高濃度則皆出現在烏魚（鋅 = 77.6、銅 = 78.2與砷 = 2.39），而錳則以吳郭魚（1.32）最高。這些二仁溪魚類肌肉及肝臟中的鋅，銅與鎘的濃度大多低於整治前的測位7~ 50%，顯示二仁溪經整治後的重金屬污染狀況已改善許多，同時魚肉中的重金屬濃度亦均符合美國食品及藥物管理局（FDA）和澳洲國家保健及醫學研究委員會（NHMRC）所訂的重金屬食用安全標準。"

Metal concentrations in the muscle and liver tissues of fishes from the Erren River in southwestern Taiwan were analyzed to evaluate the pollution status after the completion of the restoration plan in 2000. It was the first time the tissue concentrations of 4 important elements, i.e. Fe, Mn, As and Hg, were reported in fishes from this area. Samples were collected in January 2002 at the junction of the Erren River and the Sanyegong River, the most polluted section of the river. Five fish species, Megalops cyprinoids (Indo-Pacific tarpon), Chanos chanos (milkfish), Liza macrolepis (large-scaled mullet), Mugil cephalus (striped mullet) and Orechromis sp. (tilapia) were collected. A total of 91 fishes were dissected and the muscle and liver tissues taken for analysis of seven metals, Fe, Zn, Cu, Mn, As, Hg and Cd, on a wet weight basis (mg/kg). Among them, Fe and Zn were the highest, followed by Cu, Mn and As, while the Hg and Cd concentrations were the lowest. Except for As and Hg, which showed higher concentrations in the muscle tissues than in the livers, the remaining elements showed higher concentrations in livers. Significant species differences were found in all elements and tissues. The highest concentrations of Fe, Zn, Cu and Mn in muscles were found in tilapia (4.04), striped mullet (4.38), large-scaled mullet (0.20) and milkfish (0.534), respectively. The highest concentrations of As and Hg were found in striped mullet (1.59) and Indo-Pacific tarpon (0.081), respectively. The highest concentrations of Fe (3122), Hg (0.045) and Cd (0.123) were found in livers of large-scaled mullet, while striped mullet had the highest concentration of Zn (77.6), Cu (78.2) and As (2.39). The level of Mn in tilapia was 1.32 mg/kg. The Zn, Cu and Cd concentrations of the muscles and livers were mostly 7-50% lower than the levels reported on the same species of the same tissue before the restoration indicating the improvement on the metal pollution status. The heavy metal concentrations in this area were similar to various uncontaminated areas around Taiwan and all were within the food standard levels of the FDA and NHMRC.