Simon Fraser University, Dept. of Biological Sciences, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, 5421 Robertson Road, Delta, British Columbia V4K 3N2, Canada; Simon Fraser University, Dept. of Biological Sciences, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
Sci Total Environ. 2020 Apr 20;714:136746. doi: 10.1016/j.scitotenv.2020.136746. Epub 2020 Jan 20.
Legacy persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), persist for generations in the environment and often negatively impact endocrine functions in exposed wildlife. Protocols to assess the bioaccumulation potential of these chemicals within terrestrial systems are far less developed than for aquatic systems. Consequently, regulatory agencies in Canada, the United States, and the European Union rely primarily on aquatic information for the bioaccumulation assessment of chemicals. However, studies have shown that some chemicals that are not bioaccumulative in aquatic food webs can biomagnify in terrestrial food webs. Thus, to better understand the bioaccumulative behaviour of chemicals in terrestrial systems, we examined trophic magnification of hydrophobic POPs in an urban terrestrial food web that included an avian apex predator, the Cooper's hawk (Accipiter cooperii). Over 100 samples were collected from various trophic levels of the food web including hawk eggs, songbirds, invertebrates, and berries and analysed for concentrations of 38 PCB congeners, 20 OCPs, 20 PBDE congeners, and 7 other brominated flame retardants listed on the Government of Canada's Chemicals Management Plan. We determined trophic magnification factors (TMFs) for contaminants that had a 50% or greater detection frequency in all biota samples and compared these terrestrial TMFs to those observed in aquatic systems. TMFs in this terrestrial food web ranged between 1.2 (0.21 SE) and 15 (4.0 SE), indicating that the majority of these POPs are biomagnifying. TMFs of the legacy POPs investigated in this terrestrial food web increased in a statistically significant relationship with both the logarithm of the octanol-air (log K) and octanal-water partition (log K) coefficients of the POPs. POPs with a log K >6 or a log K >5 exhibited biomagnification potential in this terrestrial food web.
传统持久性有机污染物（POPs），包括有机氯农药（OCPs）、多氯联苯（PCBs）和多溴二苯醚（PBDEs），在环境中持续存在数代，并经常对暴露于其中的野生动物的内分泌功能产生负面影响。评估这些化学物质在陆地系统中生物累积潜力的方案远不如水生系统发达。因此，加拿大、美国和欧盟的监管机构主要依赖水生信息来评估化学品的生物累积性。然而，研究表明，一些在水生食物网中不具有生物累积性的化学物质可以在陆地食物网中生物放大。因此，为了更好地了解化学物质在陆地系统中的生物累积行为，我们研究了一种包括鸟类顶级捕食者库珀鹰（Accipiter cooperii）在内的城市陆地食物网中疏水性 POPs 的营养级放大作用。我们从食物网的多个营养级采集了 100 多个样本，包括鹰卵、鸣禽、无脊椎动物和浆果，并分析了 38 种 PCB 同系物、20 种 OCPs、20 种 PBDE 同系物和加拿大政府化学品管理计划中列出的 7 种其他溴化阻燃剂的浓度。我们确定了在所有生物样本中有 50%或更高检出频率的污染物的营养级放大因子（TMF），并将这些陆地 TMF 与在水生系统中观察到的 TMF 进行了比较。在这个陆地食物网中，TMF 范围在 1.2（0.21 SE）到 15（4.0 SE）之间，这表明大多数这些 POPs 正在生物放大。在所研究的陆地食物网中，传统 POPs 的 TMFs 与 POPs 的辛醇-空气（log K）和辛烷-水分配系数（log K）的对数呈统计学上显著的关系。在这个陆地食物网中，log K >6 或 log K >5 的 POPs 具有生物放大潜力。
