In the summer of 1988 the presence of aluminium in drinking water became headline news. A lorry driver discharged his load of 20 tons of an 8% solution of aluminium sulphate into the wrong tank at Lowermoor water treatment works, South West Water Authority, Cornwall. The aluminium sulphate solution was carried to the town of Camelford. Shortly afterwards people in the town were complaining that the water curdled milk, had an unpleasant taste and caused sticky lips and fingers. Later observations were of blue water and green hair.
A report of the incident was rushed out which criticised the handling of the incident and concluded that concentrations of aluminium sulphate were sufficient to give the sensations of nausea and discomfort also experienced. However the report suggested that the acidity of the water which resulted from the incident attacked copper scale in the water systems to give high concentrations of copper in the water. This gave rise to the blisters, mouth ulcers, rashes and the green bleached hair which was widely reported.
A series of recommendations were made to ensure that such an incident would never happen again. However less than a year after Camelford the same Water Authority, South West spilled 500 gallons of aluminium sulphate into a tributary of the River Torridge in North Devon. Senior sources in the water authority stated that none of the recommendations made following the Camelford incident had been implemented.
Even before Camelford greater attention was being given to aluminium. Tests had shown that babies fed on powdered milk could consume up to 2 milligrams of aluminium per day. Premature babies with immature kidneys are especially at risk and may suffer brain damage, problems of motor coordination and bone disease. Large amounts of aluminium were found in the brains of two babies examined in 1985. Manufacturers of baby milk powders have already taken action to reduce aluminium levels.
Kidney patients on dialysis machines are at risk from bone disease and anaemia cause directly by aluminium. Dialysis patients are at risk because the process uses large amounts of water. This can contain aluminium which above certain concentrations can be transferred to the blood. In addition patients on dialysis take medicines containing aluminium. Dialysis may fail to remove the aluminium from the blood if the concentration of aluminium in the fluid cleanses the blood is too high.
Recently the link between aluminium and Alzheimer’s disease has been established. This disease is a form of senile dementia. The risk from Alzheimer’s disease was stated to be 1.5 times greater in areas where the aluminium concentration exceeded 0.1 milligrams per litre as compared with less than 0.01 mg/l. Up to one million people drink water containing more than 0.2 mg/l.
It is not surprising to note that kidney patients are especially at risk from Alzheimer’s disease. In 1984 101 people in Europe died from dementia caused by dialysis. The incidence of the disease is now falling but the survival of patients on dialysis for long periods gives an increased risk due to long term exposure.
Aluminium in drinking water comes from two sources. Soluble aluminium in the soil may be leached into streams and reservoirs. Areas affected by acid rain may show even higher levels of aluminium in water. In addition aluminium sulphate is added to water to settle fine particles as part of the water treatment process. It gives water a sparkle. Iron can be used instead of aluminium and some Water Authorities already do this.
WHO = 0.2 mg/l
EC MAC = 0.2 mg/l
EC guide level = 0.05 mg/l