The farcical fallout over a fluoride overdose administered from a Brisbane water treatment plant continues, with the state government today admitting it released incorrect information on when and how the incident occurred and who was affected.
Four thousand households in Brendale and Warner were last week advised they had drunk water containing an overdose of fluoride when they were actually not affected by the incident.
Interim advice from independent water expert Mark Pascoe has found the affected water may instead have been consumed by up to 211 school children at a YMCA camp and four houses on the North Pine Water Treatment Plant site between 8am and 9am on April 30. Four hundred residents in the adjacent suburb of Joyner may have also been affected.
Last week, Premier Anna Bligh said the overdose level may have been as high as 30mg/L, but that has also been revised to 19.4mg/L. The recommended maximum level is 1.5mg/L.
Mr Pascoe’s interim advice has also revised the explanation for how the error occurred.
Premier Bligh apologised to any residents who were unduly concerned following last week’s advice and assured the community the potential health effects from the overdose were very small.
Authorities have contacted the three schools whose students were at the camp and no health concerns have so far emerged.
Mr Pascoe, who heads the International WaterCentre in Brisbane, said a slug of water containing the increased levels of fluoride had been used to backwash the North Pine water treatment plant.
The overdosed water had not been discharged through the trunk line affecting Brendale and Warner residents as initially thought, he said.
Residents were last week told the treatment plant had been shut down for maintenance but fluoride continued to be added to the system, resulting in a higher concentration of being added to the water supply when the treatment system returned to operation a short time later.
The investigation into the exact cause of the fluoride overdose continues, but Ms Bligh insisted her comments about the overdose last week were simply based on the best available information at the time.
“This incident is a totally unacceptable incident,” Ms Bliigh told reporters, while moving to allay public concerns over health effects.
“Those people who drank this water, the only possible health effects they could have encountered as a result were mild gastroenteritis symptoms.”
The state government will now write to all affected residents and those who were incorrectly notified.
The final report on the incident is due to be completed on June 26.
The State Government began adding fluoride to South-East Queensland water supplies six months ago as part of a statewide rollout to improve children’s dental health.