鼋头渚不同年龄夜鹭卵中多氯联苯污染状况及分布特征

通过对太湖鼋头渚2000年采集的2龄、3龄和4龄夜鹭所产卵中15种多氯联苯同系物残留状况的研究,发现所有样品中均检出多氯联苯,残留量最高的为PCB₁₁₈,PCB₈₇,PCB₁₀₁和PCB₁₅₃,占PCBs残留量的75%～85%.含5～6个氯原子的同系物在夜鹭卵中的PCBs残留量明显高于其它类型的同系物.同时,多氯联苯残留量随亲鸟年龄增加而明显增加.4龄卵样分别比3龄、2龄卵样中PCBs残留量高出47.5%和60.9%.统计处理结果表明:多氯联苯残留总量与亲鸟年龄呈正相关(p=0.05).PCBs总量与亲鸟年龄呈正相关(p=0.05).与欧美日等国家同类研究结果中PCB₁₅₃残留量最高的情况略有不同,本研究在夜鹭卵中发现残留量最高的是PCB₁₁₈,占PCBs残留总量的30%左右,PCB₁₅₃含量仅为PCBs残留总量的17%左右.

Polychlorinated Biphenyls Residues in Eggs of Different Ages Night Heron Breeding in Yuantouzhu,China

61 eggs of night heron (Nycticorax nycticorax) were collected in 2000 in Yuantouzhu of Tai lake, China. The breeding birds were divided into three groups by age, namely two, three, four years. The residues of 15 polychlorinated biphenyl congeners in eggs were studied. 15 congeners were found in all egg samples, and PCB118 at the highest level, PCB87, PCB101 and PCB153 at second levels. Total residues of the 4 congeners occupied about 75%-85% of sum 15 congeners residues found in eggs. It was obviously that residues of congeners containing 5-6 chlorine atoms were more than others in eggs. Residues of PCBs in eggs increased with age of breeding birds. The total PCBs concentration in eggs of four years group were higher than that of three years group, two years group by 47.5% and 60.9% respectively. Different from the result of the similar studies in European countries, USA and Japan: the residue of PCB153 is the highest, it was found that in this study the residue of PCB118 is the highest in eggs, which is about 30% of the total PCBs residues, while the PCB153 17% only.