Carole Cross, who died in 2004 aged 58, was exposed to high levels of aluminium after 20 tonnes of aluminium sulphate was dumped accidentally into the water supply at Camelford, in north Cornwall, in 1988. A post-mortem study of her brain, published today, shows that it contained high levels of aluminium and she died of a rare form of dementia.

The findings, reported to Mrs Cross’s inquest this year, are the first suggestions of a causal link between the incident and the disease.

Chris Exley, of Keele University, whose findings are published in the Journal of Neurology, Neurosurgery and Psychiatry, said of Mrs Cross’s case: “This may be a one off, although it is highly unlikely. In order to ascertain that we need to set up a rigorous and carefully planned monitoring programme of the health of the people so we can put their minds at rest.

“The people of Camelford have had this hanging over their heads for almost twenty years, but there has not been any rigorous examination or monitoring of their health since the incident. We know aluminium is linked to neurological conditions, such as Alzheimer’s, multiple sclerosis, Parkinson’s and motor neurone disease. It also goes hand-in-hand with bone diseases, such as osteoporosis, and blood disorders.

“Aluminium in the body increases with ageing but it could be that Mrs Cross was exposed to a lot of the chemical at a young age over a short period of time, which took her above the healthy threshold.

“Since her case came to light there have been reports of other people in the Camelford area either dying of neurological disorders or developing them. We are in the process of organising a proper monitoring of the health of the local population, but to carry it out will be very expensive and will require a lot of funding.”

Mrs Cross’s husband, Douglas, an environmental scientist, said: “We have been demanding testing for 18 years.” He added that there could be other people with conditions similar to those his late wife suffered, but “nobody is looking”.

The couple moved to Dulverton, Somerset, two years after the incident, but Mr Cross has been a long-serving member of the Lowermoor support group and a member of the sub-group of the House of Commons Committee on Toxicity, set up to investigate any long-term health effects of the incident.

Since the accident in July 1988, people in Camelford have complained of various forms of ill health, but a clear link has not been established. Mrs Cross’s case does not change that, but the high levels of aluminium raises questions. The full account of the case is reported today by Dr Exley, a chemist, and Professor Margaret Esiri, of Oxford University, a neuropathologist.

Mrs Cross was exposed in 1988 to drinking water containing between 500 and 3,000 times the safe limit of aluminium. She was then 44. In 2003 she began to show symptoms of brain disease.

Analysis showed aluminium levels in her brain of 23 micrograms per gram of brain. Normal brain levels range from 0 to 2 micrograms per gram.

The post-mortem examination showed that she had a rare form of Alzheimer’s.

The condition was a form of early-onset beta amyloid angiopathy, characterised by the deposition of a protein called beta amyloid in the brain’s blood vessels.

The particular pattern of deposits was very unusual, the two authors say. No other members of her family had been affected by Alzheimer’s or by psychiatric problems.

High concentrations of aluminium have been found in the “plaques” present in the brains of Alzheimer’s patients. But whether the aluminium is the cause or the consequence of the disease has not been established.

An expert committee told the Department of Health last year that it could find no evidence of delayed or persistent health effects at Camelford, but it did recommend further research.

Professor Daniel Perl, of Mount Sinai School of Medicine in New York, wrote in the journal: “If additional similar cases were to appear among the 20,000 exposed individuals then the implications of this incident would become extremely important. Only time will tell. At the very least, increased efforts towards surveillance of individuals exposed in Camelford is certainly warranted.”

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