Sodium fluoride is an industrial by-product – hydrofluosilicie acid, an inorganic chemical formula SiF6 with known scientific side-effects.

A 2002 public referendum against fluoride in the water supply was upheld by Tauranga City Council, but the bigger picture is more crucial. We're looking at consequences of residue flowing into underground waterways and oceans. Since 1970, freshwater ecosystems have declined 50 per cent, marine ecosystems 30 per cent, world forests 10 per cent with water shortages in one-third of the world's population (J B Schor, Saint Johns University).

American and Canadian scientists raised alarm over the volume of contaminates bypassing water-filtering systems, impacting on aquatic life and eco-systems.

The world's oceans and marine life are facing enormous chemical impact with loss of species. Already health defects are found in ocean fish from a combination of discharged chemicals (www.sciencedaily.com, April 2011).

Oxford University's conservation professor Dr Alex Rogers stated at 2010's International State of the Oceans and International Conservation's Conference the world faces a serious situation demanding unequivocal action at every level.

So think twice about adding fluoride, especially when Ministry of Health statistics show 47 per cent of five-year-old children who have had tooth extractions were drinking fluoridated water.

Dr Janice Priest, Herbal Ltd.