The white whales were victims of intestinal cancers caused by industrial pollutants released into the St. Lawrence River by nearby aluminum smelters.
Now research points to environmental pollutants as the cause of deadly cancers in several wildlife populations around the world. Normally rare in wildlife, cancers in California sea lions, North Sea flounder and Great Lakes catfish seem to have been triggered or accelerated by environmental contaminants.
Other animals, including Tasmanian Devils, sea turtles, woodchucks, eels and sperm whales, also have been stricken with cancers, although they appear to stem from natural causes, including viruses, spontaneous tumors, or genetic factors.
In some cases, the survival of a species and the stability and biodiversity of an ecosystem is jeopardized. The cancers also highlight the dangers that industrial activities pose – not just to animals, but to people in the same areas, exposed to the same compounds.
Cancer is very rare in animals, it's pretty much a man-made disease in various guises.
What then, of the people who worked in the surrounding region in Quebec? Well, it seems people who worked in smelters near the cancer-stricken belugas have reported many cases of lung and bladder cancers linked to coal tar exposure at the factories. Other residents have high rates of digestive tract and breast cancers.
This is an interesting SciAm article worth reading and reflecting on.