http://www.naturalnews.com/050161_aluminum_contamination_bee_deaths_dementia.html#
An insect form of Alzheimer's disease caused by aluminum contamination  may be one of the causes behind an ongoing decline in populations of  bees and other pollinators, according to a study conducted by  researchers from the universities of Keele and Sussex and published in  the journal 
PLOS ONE.
The researchers found that honeybees  had levels of aluminum in their bodies equivalent to those that could  cause brain damage in humans.
"Aluminium is a known neurotoxin  affecting behaviour in animal models of aluminium intoxication," said  researcher Chris Exley, an expert on human aluminum exposure, as  reported by the UK's 
Daily Mail. "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?"
[h=2]"Pathological" aluminum levels[/h]Researchers  from the University of Sussex first collected pupae from colonies of  wild-foraging bumblebees, then sent these off to Keele University for  analysis of their aluminum content.
Pupae are sacks that  bumblebee larvae develop in before emerging into their adult forms. The  pupae in the study were found to contain between 13 and 200 parts per  million (ppm) of aluminum.
Just 3 ppm is "considered as potentially pathological in human brain tissue," the researchers said.
Prior  studies had shown that bees do not actively avoid aluminum-contaminated  nectar while foraging, but the new study was among the first to show  the consequences of this behavior.
Bees use sophisticated cognitive processes to forage for food over wide territories, and to communicate with other 
bees.  Because aluminum has been shown to have negative effects of animal  cognition, the new study raises the possibility that aluminum poisoning  might be contributing to crashing populations of bees worldwide.
[h=2]Addictive pesticides?[/h]Dementia  caused by aluminum poisoning is still likely to be just one of many  factors currently devastating pollinator populations, however.
'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," Exley said.
Much attention has focused on the family of  pesticides known as neonicotinoids – systemic pesticides that  infiltrate every portion of a plant, including the pollen and nectar.  Three neonicotinoids have already been banned in Europe due to evidence  of harm to pollinators.
Alarmingly, two recent studies published in the journal 
Nature  suggest that bees may actually be particularly attracted to plants  treated with neonicotinoids, preferentially visiting them over untreated  plants. That's because the pesticides contain a chemical similar to  nicotine, which the bees may be getting addicted to much as humans get  addicted to the nicotine in cigarettes.
"There's a conundrum that  they are attracted to the stuff that actually is having a negative  impact on their motor function and their ability to collect food and  forage," said researcher Geraldine Wright of Newcastle University.  Wright and colleagues offered honeybees and bumblebees a choice between  sugar water solutions either containing or not containing low doses of  neonicotinoids. The bees drank more from the pesticide-laced food  sources.
The second study, conducted by researchers from Queen  Mary University of London and Royal Holloway, University of London,  found that bees infected with parasites were even more likely to drink  from neonicotinoid-contaminated nectar than healthy bees. And while the  pesticide did appear to slow the progress of the infections, it did not  increase the bees' life expectancy.
In fact, both healthy and  unhealthy bees who consumed neonicotinoid-laced nectar showed negative  side effects, including suppressed appetite. Healthy bees who drank more  of the nectar had shorter lifespans than those who drank less.
Sources:
http://www.dailymail.co.uk
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http://www.dailymail.co.uk