Long-term effects of Britain's worst water poisoning disaster are still not known, a report says.
Water supplies to 20,000 people in the Camelford area were affected
An independent inquiry started three years ago into the contamination in July 1988 of water supplies to 20,000 people in Camelford, north Cornwall.
Twenty tonnes of aluminium sulphate were poured into the wrong tank at the Lowermoor water works near Bodmin.
Local people have complained over the years of a variety of symptoms from brain damage to joint problems.
The third and latest report into the health effects of the incident, described by the Department of Health as the most comprehensive yet, was ordered by former environment minister Michael Meacher in 2001.
Scores of people were interviewed by the group, chaired by Professor Frank Woods of Sheffield University, which included experts in toxicology and child health as well as local representatives.
The 400-page draft report concluded it was unlikely that the chemicals involved in the incident would have caused any delayed or persistent health effects.
No conclusive link was found between the incident and the chronic symptoms and diseases.
But the group recommended that further work should be undertaken on the effects on the development of those under the age of one at the time of the incident.
The incidence of diseased joints in the affected area should also be investigated, as well as the effect of contaminants on neurological health.
There will be a 12-week consultation period for the report and a public meeting will be held in Camelford on 17 February.