Polychlorinated biphenyl (pcb) contamination on Unalaska Island in the Aleutian archipelago

• Main Author: Adams, Elise M
• Format: Thesis
• Language: English
• Published: 2018
• Subjects: QH301 Biology; Arctic
• Online Access: http://openknowledge.nau.edu/5268/; http://openknowledge.nau.edu/5268/1/Adams_2018_PCB_contamination_Unalaska_Island.pdf

Polychlorinated biphenyls (PCBs) are a group of man-made, hydrophobic organochlorines that persist at highly toxic levels in the environment and biomagnify within food webs. Although banned, their continued release from pre-banned products and persistence in the environment impact human and wildlife health. PCBs are transported to the Arctic via global distillation and biomagnify to high levels in the lipid-rich food web. Thus the long-range transportation capacity of PCBs can affect food webs far from the area of release. In addition, the Arctic contains thousands of World War II and Cold War formerly used defense (FUD) sites, many of which are also a local source of PCB contamination. PCBs have the ability to modify or suppress thyroid, reproductive and immune function. Exposure can reduce cognitive function and greatly increase the risk of developing cancer, hypothyroidism and a host of other negative health effects. Human and animal exposure occurs via ingestion of contaminated food. PCB concentrations were analyzed in threespine stickleback (Gasterosteus aculeatus) and subsistence foods important to the Qawalangin Tribe of Unalaska (i.e., salmonid species and blue mussels (Mytilus edulis)). PCBs were extracted from samples using a modified QuEChERS method. Mean PCB concentrations were quantified in target species to assess potential risks associated with subsistence foods and to detect a difference between global and local sources of PCB contamination. Two FUD sites showed elevated levels of PCBs that exceed safe consumption guidelines. These results support the need to remediate the FUD sites of “Building 551/T Dock to Airport” and “Delta Western”. More generally, these results provide further evidence of the continued problem of PCB contamination at FUD sites in the Arctic.