PCB. Lingering threat.
Slinking up food chains, silent.
Killing the killers.
PCBs – polychlorinated biphenyls – were widely used in a variety of manufacturing techniques until they were linked to health problems such as increasing the risk of cancer, disrupting the immune system and impairing reproduction. Despite a ban on their use, the compounds remain an environmental contamination and can accumulate in the tissues of animals, passing up the food chain to accumulate in dangerous levels in apex predators.
Whilst killer whales are one of the most populous mammal species on the planet, research by Desforges et al (2018) suggests that PCB pollution could result in a collapse in over 50% of the world’s killer whale populations. The researchers amalgamated data on PCB concentrations in killer whale tissues from across the world and modelled the predicted impacts of PCB pollution over the next 100 years. The results highlight how important it is to be aware of potential environmental issues, even with species that appear to be thriving.
Original research: http://science.sciencemag.org/content/361/6409/1373