In a new paper published in the journal Environmental Toxicology and Chemistry (Zahara et al. 2015) myself and others from Dr. Christy Morrissey’s avian ecotoxicology lab at the University of Saskatchewan examine latent cognitive effects (learning and memory) of juvenile PCB exposure in the European starling. The research is the major output of my environmental toxicology research internship held with Dr. Morrissey from September 2012-March 2013.
The study, which tested only birds that were exposed to PCBs (a hormone disrupting chemical) in their first 18 days of life, found that birds dosed with higher amounts of PCBs were more error prone and took longer to complete a learning task than lower-dose or non-dosed birds. This research is particularly important since it deals with the same levels of PCBs that starlings and other birds are readily exposed to in their environment. Impairments to cognition might impact the ability of starlings to learn/remember locations of stored food or reduce their ability to build and remember the spatial maps necessary for long-term migration. A companion study on these same birds (Flahr et al. 2015) provides evidence that low-level PCB exposure also delays the onset of starling migratory behaviour.
Importantly, these papers remind us that scientific knowledge about contaminants is always updating. Even 40 years after PCB usage was banned in North America, scientists continue to discover previously unknown environmental/human/nonhuman health consequences of these and other chemicals. Undoubtedly, there are numerous other latent/unknown consequences of PCBs that have yet to be discovered.
Zahara, A., Michel, N., Flahr, L., Ejack, L., & Morrissey, C. ‘Latent cognitive effects from low-level PCB exposure in juvenile European starlings, Sturnus vulgaris.’ Environmental Toxicology and Chemistry DOI: 10.1002/etc.3084
Flahr, L., Michel, N., Zahara, A., Jones, P., & Morrissey, C. (2015). ‘Developmental exposure to Aroclor 1254 alters migratory behaviour in juvenile European starlings (Sturnus vulgaris),’ Environmental Science and Technology 49: 6274-6283.