Scientists found unusually high levels of aluminium contamination in bees, suggesting aluminium-induced cognitive dysfunction could be playing a major role in the mysterious decline of bumblebee populations.
Aluminium has been known to kill off fish in acid lakes, and has also been linked to forest and crop decline, Keele University reported.
Past research has shown bees do not actively avoid nectar containing the ecotoxicant, suggesting they may be accumulating aluminium over time. Researchers collected pupae from colonies of naturally foraging bumblebees and analyzed their aluminium content. They found the pupae had significant aluminium contamination, with contents ranging between 13 and 200 parts per million. Smaller pupae were shown to have the highest levels of contamination.
These findings are concerning because an aluminium value of only three ppm in human brain tissue would be considered "potentially pathological."
"It is widely accepted that a number of interacting factors are likely to be involved in the decline of bees and other pollinators - lack of flowers, attacks by parasites, and exposure to pesticide cocktails, for example," professor Chris Exley a leading authority on human exposure to aluminium, from Keele University. "Aluminium is a known neurotoxin affecting behaviour in animal models of aluminium intoxication. Bees, of course, rely heavily on cognitive function in their everyday behaviour and these data raise the intriguing spectre that aluminium-induced cognitive dysfunction may play a role in their population decline - are we looking at bees with Alzheimer's disease?"
The findings were published in a recent edition of the journal PLOS One.
