摘要
1996～1997期间,在一个富营养湖(湖E)和一个贫营养湖(湖O)中进行了富营养化和有机污染物(PCB,DDTs及γ-HCH)的交互作用研究,两湖的地貌形态和水化学相似。集水区的土壤样品表明两湖暴露于相似的大气条件下。与湖O相比湖E没有观测到生物稀释。湖E的沉积物(1.5倍)、表面沉积物(1.4倍)和河鲈(Perca fluviatilis)(2.4倍)的有机碳和脂质物质中的PCB水平较高,并且微粒的沉降流较大,沉积物捕集器和沉淀物表面PCB的水平也较高。湖E中PCB的大部分转运主要是靠浮游植物。DDD/DDE比值较高似乎与p,p’-DDT的高负载相关而非厌氧的原因。所记录的湖O深层沉积岩心的高DDD/DDE比值和sDDT的高水平以及在此期间沉积最多,大概是由于从集水区流入的前体DDT最高的缘故。
Interactions between eutrophication and organic pollutants (PCB, DDTs and y-HCH) were investigated during 1996-1997 in two lakes, one eutrophic (Lake E) and one oligotrophic (Lake O) but with otherwise similar morphometry and water chemistry. Soil samples from the watersheds indicated similar atmospheric exposure of the lakes. No biomass dilution was observed in Lake E compared to Lake O. Lake E had higher levels of PCB based on organic carbon and lipid mass in sedimenting matter (1.5x), surface sediment (1.4x) and perch (Perca fluviatilis) (2.4x), and also higher settling fluxes of particulate matter and PCB measured in sediment traps and in surface sediment. Phytoplankton was responsible for most of the PCB transport to the sediment in Lake E. Higher DDD/DDE ratios seemed to correlate to a high load of p,p'-DDT more than to that of anaerobic conditions. A high DDD/ DDE ratio was recorded in the deep sediment core from Lake O together with high levels of sDDT and was also highest in the sediment traps during periods with, probably, the highest runoff of parental DDT from the watershed.
