by Colin Fernandez
- Bumblebees found to be contaminated with elevated levels of aluminium
- Scientists found they had levels that would cause brain damage in humans
- Researchers say metal pollution may be contributing to decline of insects
Bees may be declining because they are suffering dementia compared to Alzheimer’s caused by eating large amounts of aluminium.
A scientific study found high amounts of aluminium contamination in bees at levels that would cause brain damage in humans.
Bees rely on their tiny brains to navigate to flowers to collect pollen and nectar to eat.
Researchers from the universities of Keele and Sussex studied the levels of aluminium in pupae – the bag-like form bumblebee larvae before they emerge as fully grown adults.
The scientists found that the pupae contained levels of between 13 and 200 ppm (parts per million).
To put it in context, just 3ppm would ‘be considered as potentially pathological in human brain tissue.’
Previous research has found when bees forage for nectar they do not actively avoid nectar which contains aluminium.
Researchers at University of Sussex collected pupae from colonies of naturally foraging bumblebees and sent them to Keele University where their aluminium content was determined.
Pesticide residues have been seen as one of the most significant causes of a decline in bee numbers.
But the researchers, whose work is published in the journal Public Library of Science One, suggest the possibility that this aluminium is also contributing to the decline.
Professor Chris Exley an expert on human exposure to aluminium, from Keele University said: ‘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.
‘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 Alzheimer’s society advise that although aluminium was linked initially with Alzheimer’s disease in humans ‘the link has not been proven despite continuing investigation’.
ARE BEES HOOKED ON NICOTINE?
Bees may be getting hooked on nectar laced with nicotine-related chemicals in a similar way to how humans are addicted to the drug in cigarettes.
Many insecticides contain traces of so-called neonicotinoids, which translates to ‘new nicotine-like insecticides’.
And despite not being able to taste them, studies have discovered bees – especially those with parasites – will seek out plants laced with such chemicals.
Like nicotine, the neonicotinoids act on certain receptors in the nerve synapses of insects.
They are more toxic to invertebrates than they are to mammals and birds.
Initially, neonicotinoids were used due to their low-toxicity to many so-called beneficial insects, such as bees.