摘要
我们于1988～2002年对未孵化的苍鹰卵(n=57)进行了调查,并与1971～1978年的卵(n=134)进行了比较,早期PCBs、∑DDT和HCB的浓度为(mg/kg脂重)50.1、126.6和117.7,而后期相应的值显著低,分别为27.7、4.1和0.1。但最近8～10年内,PCB的浓度相对稳定。残留物浓度波动在巢内低于巢间。年龄不影响卵中污染物的积累。1971～1978年测得的卵壳指数显著低,而2001～2002年测得的指数却相当高,与18世纪末的数字相当。我们提出了卵壳指数效应浓度的临界值。DDT族残留物对每处鸟巢的离巢幼鸟数目有影响。
We investigated unhatched eggs (n=57) of Goshawks (Accipiter gentilis) from the period 1988-2002 and compared them with eggs (n = 134) from 1971-1978.Mean concentrations of PCBs,Σ DDT and HCB in the earlier period were (mg kg-1 lipid weight) 50.1,126.6,and 117. 7,while the values from the later period were statistically significantly lower:27.7,4.1,0.1, respectively.Nevertheless,the concentration of PCB relatively constant during the last 8-10 years.The variability of residues was lower within clutches than among clutches.No agedependent accumulation in eggs could be demonstrated.A statistically significant lower shell index was measurable for the period 1971-1978,while this index dunng 2001-2002 was relatively high as it was during the late 18^(th) century.We are suggesting a threshold value for effect concentrations on shellindex.Residues of the DDT-group had an influence on the number of fledged young per nest site.
