Post by Lisa Petrison on Nov 14, 2011 9:26:24 GMT -5
Global study reveals algae in world's water is causing Alzheimer's
Sunday Herald, The, Apr 3, 2005 | by Rob Edwards Environment Editor
A HIGHLY toxic acid that could cause degenerative brain diseases such as Alzheimer's has been discovered in the algal blooms that plague waters in Scotland and around the world.
Scientists fear that the spread of "blue-green" algae across lochs and seas, caused by pollution, is now putting human health at risk. There is "a potential for widespread human exposure" to the toxin in the algae, they warn.
Algal blooms in Scotland are known to be fed by discharges from sewers, and some of them have proved toxic to fish, shellfish and pets. But until now they have never been linked to the occurrence of brain disease in humans.
Now an international team of researchers, including three from the University of Dundee, have detected a neurotoxin in 29 out of the 30 samples of blue-green algae they have tested. The samples were taken from a variety of water sources in Scotland, Northern Ireland, the Netherlands, Israel, India, Australia, the US and elsewhere.
The toxin is a naturally occurring amino acid known as beta- methyl-amino-alanine, or BMAA for short. It has been blamed for causing a high incidence of a disease similar to Alzheimer's amongst the Chamorro people on the island of Guam in the Pacific.
BMAA has also been found in the brain tissue of Alzheimer's patients in Canada, suggesting it may have caused the disease.
Although the way in which toxins in algal blooms could infect humans is still unclear, scientists stress that precautions should be taken now, particularly with our drinking water supplies.
"We now know that BMAA is widely produced by cyanobacteria (blue- green algae) from throughout the world, " said Professor Geoffrey Codd, one of the researchers from the School of Life Sciences at Dundee University.
"This indicates that human exposure to BMAA may also occur more widely and that BMAA should be monitored in water resources, including reservoirs, if they contain cyanobacteria.
"Now that we know about BMAA in cyanobacteria, steps can be taken to reduce the risks to health which the substance may present."
According to Codd, this is the first time that such a toxin has been found to be so widespread amongst algal blooms.
"Samples of cyanobacteria were collected from freshwaters, seas, soil, lichen, a cave and a hot spring from across the world. Of a sample of 30 cultures, 95-per cent of them were shown to produce BMAA, " said Codd.
The finding was "of ecological and evolutionary significance", he suggested. There was no doubt that BMAA was "neurotoxic", but its precise links with human neurological diseases were "uncertain".
BMAA has previously been discovered in the roots of ancient palm- like plants known as cycads. On Guam, it concentrates in the flying foxes that feed on cycads, and then in the Chamorro people who eat the flying foxes.
BMAA has been found in the brains of Chamorro people who have died from a paralytic dementia known as ALS/PDC, but not in those who have died from other causes. The acid binds to proteins in the body and is released over years, causing it to be branded as a "slow toxin".
But in 2003, when BMAA was detected in the brains of nine Canadian Alzheimer's patients, scientists started suspecting that it might have come from blue-green algae. So they decided to analyse as much algae as they could from around the planet.
The results will be published tomorrow in the Proceedings of the National Academy of Sciences of the USA. Along with Codd, Dr James Metcalf and Louise Morrison from Dundee University, the research team includes experts from institutes in Hawaii, California and Sweden.
"We were surprised to find that BMAA is produced by such a diversity of cyanobacteria throughout the world, " said research leader, Paul Alan Cox, from Hawaii's Institute for Ethnomedicine at the National Tropical Botanical Garden.
Algal blooms are a natural phenomenon, but their frequency and extent are being boosted by pollution. Their growth is enhanced by phosphates from sewage, detergents, fertilisers and fish farms, as well as by the global warming caused by greenhouse gases like carbon dioxide.
Environmental groups pointed out that some efforts were already being made by industry and regulators to reduce the pollution that feeds algal blooms in lochs. But much more needed to be done, they argued.
"Algal blooms were a serious enough problem already. Now that there is a possible link to human brain problems, we should redouble our efforts to reduce the pollution which helps them occur, " said Mike Donaghy, freshwater policy officer with the environmental group, WWF Scotland.
"More toxic algae is another nasty little side effect of climate change."
The Scottish Environment Protection Agency, the government's green watchdog, was unable to comment on the new research last week.
www. pnas. org
www. dundee. ac. uk/ biocentre
www. ntbg. org
Sunday Herald, The, Apr 3, 2005 | by Rob Edwards Environment Editor
A HIGHLY toxic acid that could cause degenerative brain diseases such as Alzheimer's has been discovered in the algal blooms that plague waters in Scotland and around the world.
Scientists fear that the spread of "blue-green" algae across lochs and seas, caused by pollution, is now putting human health at risk. There is "a potential for widespread human exposure" to the toxin in the algae, they warn.
Algal blooms in Scotland are known to be fed by discharges from sewers, and some of them have proved toxic to fish, shellfish and pets. But until now they have never been linked to the occurrence of brain disease in humans.
Now an international team of researchers, including three from the University of Dundee, have detected a neurotoxin in 29 out of the 30 samples of blue-green algae they have tested. The samples were taken from a variety of water sources in Scotland, Northern Ireland, the Netherlands, Israel, India, Australia, the US and elsewhere.
The toxin is a naturally occurring amino acid known as beta- methyl-amino-alanine, or BMAA for short. It has been blamed for causing a high incidence of a disease similar to Alzheimer's amongst the Chamorro people on the island of Guam in the Pacific.
BMAA has also been found in the brain tissue of Alzheimer's patients in Canada, suggesting it may have caused the disease.
Although the way in which toxins in algal blooms could infect humans is still unclear, scientists stress that precautions should be taken now, particularly with our drinking water supplies.
"We now know that BMAA is widely produced by cyanobacteria (blue- green algae) from throughout the world, " said Professor Geoffrey Codd, one of the researchers from the School of Life Sciences at Dundee University.
"This indicates that human exposure to BMAA may also occur more widely and that BMAA should be monitored in water resources, including reservoirs, if they contain cyanobacteria.
"Now that we know about BMAA in cyanobacteria, steps can be taken to reduce the risks to health which the substance may present."
According to Codd, this is the first time that such a toxin has been found to be so widespread amongst algal blooms.
"Samples of cyanobacteria were collected from freshwaters, seas, soil, lichen, a cave and a hot spring from across the world. Of a sample of 30 cultures, 95-per cent of them were shown to produce BMAA, " said Codd.
The finding was "of ecological and evolutionary significance", he suggested. There was no doubt that BMAA was "neurotoxic", but its precise links with human neurological diseases were "uncertain".
BMAA has previously been discovered in the roots of ancient palm- like plants known as cycads. On Guam, it concentrates in the flying foxes that feed on cycads, and then in the Chamorro people who eat the flying foxes.
BMAA has been found in the brains of Chamorro people who have died from a paralytic dementia known as ALS/PDC, but not in those who have died from other causes. The acid binds to proteins in the body and is released over years, causing it to be branded as a "slow toxin".
But in 2003, when BMAA was detected in the brains of nine Canadian Alzheimer's patients, scientists started suspecting that it might have come from blue-green algae. So they decided to analyse as much algae as they could from around the planet.
The results will be published tomorrow in the Proceedings of the National Academy of Sciences of the USA. Along with Codd, Dr James Metcalf and Louise Morrison from Dundee University, the research team includes experts from institutes in Hawaii, California and Sweden.
"We were surprised to find that BMAA is produced by such a diversity of cyanobacteria throughout the world, " said research leader, Paul Alan Cox, from Hawaii's Institute for Ethnomedicine at the National Tropical Botanical Garden.
Algal blooms are a natural phenomenon, but their frequency and extent are being boosted by pollution. Their growth is enhanced by phosphates from sewage, detergents, fertilisers and fish farms, as well as by the global warming caused by greenhouse gases like carbon dioxide.
Environmental groups pointed out that some efforts were already being made by industry and regulators to reduce the pollution that feeds algal blooms in lochs. But much more needed to be done, they argued.
"Algal blooms were a serious enough problem already. Now that there is a possible link to human brain problems, we should redouble our efforts to reduce the pollution which helps them occur, " said Mike Donaghy, freshwater policy officer with the environmental group, WWF Scotland.
"More toxic algae is another nasty little side effect of climate change."
The Scottish Environment Protection Agency, the government's green watchdog, was unable to comment on the new research last week.
www. pnas. org
www. dundee. ac. uk/ biocentre
www. ntbg. org