Nano Girl Michelle Dickinson: The quality of science

The fluoridation level in our water has been found to greatly reduce tooth cavity levels without creating health risks. Photo / Stephen Parker

Putting water fluoridation in DHB hands will cut through muddled, non-scientific debate.

Often, when I meet people, we talk science. Many are well-informed and passionate about science, but some quote science "facts" from their own research that are patently false and when I ask for the original source of their information, Facebook is a common reference.

The internet and social media are powerful things, putting information at our fingertips and helping us understand new topics more readily than ever before. Almost 80 per cent of us search for health information online as we try to make informed decisions about our lives. The internet however, also contains a wealth of misinformation and false claims hidden behind seemingly credible websites and well-presented infographics.

Scientists can't make claims based on what we see online, or one-off experiments. The scientific community relies on peer-reviewed publications to advance good science - solid experimentation is evaluated by experts in the field who will often reject applications for publication because they fail to meet the quality standard.

This means that when you read a high quality, peer-reviewed journal, the facts and figures have already been through many hoops to ensure that the evidence and conclusions are solid. As a professional scientist and science communicator, I work hard to make genuine, peer-reviewed science accessible to the public. Suffice to say that much of the content you will find online, however credible it may seem, is not as responsible, or subject to such rigorous (if any) scrutiny.

This week one of the most consistent debates prolonged by purveyors of non-science woo woo - the fluoridation of our water and associated health effects - entered the news again as Health Minister Jonathan Coleman and Associate Health Minister Peter Dunne announced proposed legislative changes to allow district health boards, rather than local authorities, to determine which community water supplies are fluoridated.

In my view this is a sensible policy, as there is a far greater likelihood that decision-makers in the regional public health services will be able to approach the issue from a position of robust science, in contrast to some local bodies who have spent a great deal of time and ratepayers' money addressing the lobbying efforts of the scientifically misinformed.

Scientists can't make claims based on what we see online, or one-off experiments.

The science from 10 major scientific review papers is very clear: water fluoridation is effective at reducing tooth cavity levels in both primary and permanent teeth in children, as well as reducing instances of dental abscesses, toothache and admission to hospital for general anaesthetics.

A New Zealand-commissioned review by the Prime Minister's Chief Science Adviser Sir Peter Gluckman and President of the Royal Society of New Zealand Sir David Skegg, "Health Effects of Water Fluoridation: a Review of the Scientific Evidence", found that fluoridation levels used in New Zealand water supplies created no health risks and result in 40 per cent lower lifetime incidence of tooth decay among children and adolescents, a 48 per cent reduction in hospital admissions for the treatment of tooth decay among children aged 0-4 and a 30 per cent reduction in tooth decay among adults aged 45 years and over.

I've met many fierce anti-fluoride campaigners who claim fluoride is a toxin. In large doses it is - as are most things - but at low doses supplementing the natural amount already in our water it is beneficial, especially for our most vulnerable communities. Considering that some black teas contain up to 839mg of fluoride per kilogram, I'm wondering why the anti-tea brigade hasn't started lobbying yet.

For me, any move to reduce the impact of poor quality science and base our decisions on genuine, peer-reviewed information is a positive one for New Zealand.

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Dr Michelle Dickinson, also known as Nanogirl, is an Auckland University nanotechnologist who is passionate about getting Kiwis hooked on science. Tweet her your science questions @medickinson