白令海、楚科奇海、加拿大海盆沉积物重金属潜在生态风险评价

利用电感耦合等离子体质谱仪(ICP-MS仪)测定北极亚北极海区的白令海、楚科奇海、加拿大海盆海区沉积物中8种重金属元素的浓度,并对8种重金属元素的地球化学特征、空间分布特征、可能来源进行了研究。研究发现,Cr、Zn、Co、Ni、Cu、Pb、Bi有很强的相关性,说明其具有相似的来源,且空间分布的特征相似,均为沉积物底质中的浓度在研究区内呈现出在白令海和楚科奇海较低,在加拿大海较高的特征;而Cd与其他重金属空间分布差异明显。应用Hakanson潜在生态危害指数法与内梅罗综合污染指数法对各重金属的潜在风险进行了评价,其中,用Hakanson潜在生态危害指数法求得北极整体生态风险性指数值达到43.01,处于轻微生态风险状态,Co重金属元素风险最大。研究结果表明,两种评价结果得出类似规律,白令海生态安全性最高,楚科奇海大部分地区生态安全性较高,加拿大海盆的生态安全性最差。在研究区内整体上呈现出由高纬度向低纬度生态安全逐渐增高,西部生态风险性大于东部的趋势。

Potential Ecological Risk Assessment of Heavy Metals in Bering Sea,the Chukchi Sea,and the Canada Basin

The concentrations of eight heavy metals in sediment in Arctic and subarctic areas of the Bering Sea, the Chukchi Sea, and the Canada Basin were determined using an inductively coupled plasma mass spectrometer. Then, the geochemical and spatial distributions, as well as the correlations, of the eight elements were studied. The results showed that the Zn, Bi, Pb, Cu, Ni, Co, and Cr concentrations were strongly correlated, which indicated they had similar sources and spatial distribution characteristics. The concentrations of the above seven elements in sediments in the Bering Sea and the Chukchi Sea were lower than those in the Canada Basin. However, the spatial distribution of Cd obviously differed from that of the other seven elements. Finally, the Hakanson Potential Ecological Risk Index and the Nemerow Comprehensive Pollution Index were used to evaluate the potential ecological risk of the eight metals. The results showed that the Hakanson Index of the Arctic area reached 43.1, which indicated that this area has a slight risk of ecological damage. Co posed the greatest ecological risk. The results of both methods showed the same distribution trend of the ecological risk of the heavy metals. The Bering Sea had the lowest ecological risk, while most of the Chukchi Sea was relatively risk-free and the Canada Basin had the highest ecological risk. The degree of heavy metal pollution showed a gradually decreasing trend from high to low latitudes, and the degree of pollution of the Western Hemisphere was greater than that of the Eastern Hemisphere.