Screen Camelford residents, researchers say, after woman's death linked to poisoned water supplyBMJ 2006; 332 doi: http://dx.doi.org/10.1136/bmj.332.7548.992-b (Published 27 April 2006) Cite this as: BMJ 2006;332:992
Researchers investigating the death of a woman in 2004 from a rare form of Alzheimer's disease, which has been linked to the poisoning of the drinking water supply in a town in south west England, are calling for all local residents to be monitored for any signs of impaired cognitive function (Journal of Neurology, Neurosurgery, and Psychiatry 2006 doi: 10.1136/jnnp.2005.086553).
But local heath officials say that the health of local people is already under review. North and East Cornwall Primary Care Trust's director of public health, Denis Cronin, told the BMJ, “When you read the report [published in the journal] you immediately jump to the conclusion that there is nothing taking place. But over the last 18 years considerable pieces of work have been done.” All the evidence showed that “the health of the population in north Cornwall is very good,” he added.
Twenty tonnes of aluminium sulphate were dumped into the wrong tank at water treatment works supplying Camelford in 1988. Up to 20 000 people were exposed to concentrations of aluminium of between 500 and 3000 times the European Union's acceptable limit.
The West Somerset coroner ordered an investigation into the woman's death, and a neuropathological examination was done by Chris Exley, of the Birchall Centre for Inorganic Chemistry and Materials Science at Keele University, and neurologist Margaret Esiri of the Radcliffe Infirmary, Oxford. In their report they say that they found “a very unusual pattern of severe sporadic &bgr; amyloid angiopathy, a condition that has been described only occasionally.” Affected areas of the brain cortex showed high concentrations of aluminium—up to 11 times normal amounts. The woman had no family history of neurological or psychiatric disease.
The presence of aluminium and &bgr; amyloid is “unlikely to be wholly adventitious,” the researchers added, calling for further assessments of the cognitive function of people who drank the contaminated water, including neuropathological examinations.
In an accompanying commentary in the journal, neuropathologist Daniel Perl of the Mount Sinai School of Medicine in New York warns that “the association of aluminium and Alzheimer's disease has a long and rather controversial history” due to a lack of epidemiological data. But if more cases were to be found as a result of Camelford “then the implications of this incident would become extremely important,” he writes.
But Mr Cronin warned, “Any research should be structured to produce useful information that emonstrates causality or rules it out.” He added that there must be a clear epidemiological study design.
A subgroup of the independent Committee on Toxicity of Chemicals in Food, Consumer Products, and the Environment was due to give guidance on research design in a report due out later this year. The subgroup's draft paper on the incident, published in 2005, found “no conclusive link” between the poisoning and health problems reported by the people of Camelford.