苗栗海岸土壤重金屬含量分析

Heavy metal contents in soil in Miaoli Coast

本研究針對苗栗海岸，自竹南至苑裡間50公里海岸線，依地理位置分26段，再依河流出口現況及潮間帶寬度設置採樣站，採取棲地基質樣本，主要為沙粒，各樣本以X-射線螢光光譜儀進行32種重金屬濃度測定。採樣工作於2014-2015年進行，第2年採樣除部分增加樣站外，主要為重複採樣，共有85個樣點，每採樣點分別進行3次重複採樣，檢測32種重金屬元素，共計255筆樣本資料進入分析。龍鳳港測得鈦9056.6ppm，錳731.8ppm，鐵37719.1ppm，都是苗栗海岸的最大值，後龍溪口的鋯、鋅、鉛、釷、鉀、銣、硫等數值高，顯示後龍溪略受污染。砷在通霄測得40.36ppm，較苗栗海岸整體平均值高出很多，需追蹤砷的污染源。苑裡鎮的沙丘亦頗為發達，漁港內常有季節性的沙子大量堆積，致使使用率偏低，目前無污染狀況。 This study was an investigation of heavy metal contents in a 50 km coastline in Miaoli. The coast between Zhinan and Yuanli were divided into 26 segments according to estuary and geographical locations to obtain habitat samples, which were mainly sand, from 2014 to 2015. In the second sampling year, in addition to adding more sample stations mainly for repeated sampling purposes, a total of 255 sand samples were gathered to measure the concentration of 32 heavy metals by X-ray fluorescence spectrometer. Multivariate statistical analysis was performed on the quantitative data to compare the samples. Four groups of elements were further categorized based on ordination of principal component analysis and dendrograms from cluster analysis. At Longfeng Port, measurements showed 9056.6ppm of titanium, 731.8ppm of manganese, 37719.1ppm of iron, all highest values in Miaoli coast. Estuary of Houlong showed higher values in zirconium, zinc, lead, thorium, potassium, rubidium, sulfur, indicating slight contamination. Arsenic was measured at 40.36ppm in Tungshiau, a value much higher than the overall average of Miaoli coast. This shows the need to investigate the source of arsenic pollution. Dune in Yuanli Town was developed; fishing port often had seasonal accumulation of sand, and thus it is low in utilization rate. Currently it is pollution-free.

This study was an investigation of heavy metal contents in a 50 km coastline in Miaoli. The coast between Zhinan and Yuanli were divided into 26 segments according to estuary and geographical locations to obtain habitat samples, which were mainly sand, from 2014 to 2015. In the second sampling year, in addition to adding more sample stations mainly for repeated sampling purposes, a total of 255 sand samples were gathered to measure the concentration of 32 heavy metals by X-ray fluorescence spectrometer. Multivariate statistical analysis was performed on the quantitative data to compare the samples. Four groups of elements were further categorized based on ordination of principal component analysis and dendrograms from cluster analysis. At Longfeng Port, measurements showed 9056.6ppm of titanium, 731.8ppm of manganese, 37719.1ppm of iron, all highest values in Miaoli coast. Estuary of Houlong showed higher values in zirconium, zinc, lead, thorium, potassium, rubidium, sulfur, indicating slight contamination. Arsenic was measured at 40.36ppm in Tungshiau, a value much higher than the overall average of Miaoli coast. This shows the need to investigate the source of arsenic pollution. Dune in Yuanli Town was developed; fishing port often had seasonal accumulation of sand, and thus it is low in utilization rate. Currently it is pollution-free.