Toxic effects long lasting
While volunteers were removing dead birds and oily debris from Vancouver Island beaches, weathered oil containing high levels of toxic polycyclic aromatic hydrocarbons (PAHs), were accumulating on the ocean floor. PAHs are extremely toxic and are considered hazardous waste by the Environmental Protection Agency.
The PAHs, found naturally in crude oil, are concentrated either through refining or during weathering after a spill. The west coast oil spill consisted of bunker C oil which contains more PAHs than crude oil because it is more refined.
Oceanographer Silvaine Zimmermann of Vancouver says that the most dangerous form of PAH, benzo (a) pyrene (BaP), has been shown to biochemically attach to a cell's DNA. This could result in faulty replication of genes. "Tumors and cancer are common in beluga whales of the St. Lawrence. One of the main reasons they are dying out is due to BaP contamination", she explained.
PAHs are also felt to be one cause of the high incidence of tumors and lesions in fish in Vancouver's Burrard Inlet. A recently released Environment Canada showed that 58 percent of the English sole sampled in the vicinity of the Port Moody oil refineries have liver lesions, tumors and cancer. These refineries release large volumes of PAHs into Burrard Inlet.
Grey whales are due back on the west coast in the spring. Their bottom feeding habits could easily spell doom for them. They scoop up mouthfuls of sand, which is then filtered out through the baleen. If the oily tar contaminating the sediments remains as soft as it is now, it will stick to and gum up the baleen. Even if the oil hardens, any ingestion will poision the whales with PAHs.
