In the teeth of the evidence

Teaching final year Environmental Chemistry at The Institute is the best of fun and I keep unearthing facts that are relevant to the course and really interesting as well.  I hope the students are finding the whole thing as riveting as I am.  I have no intention of teaching the whole thing as an exercise in I talk and flick through powerpoint slides and you listen and maybe take notes.  That's the worst possible learning protocol and I have to prep a lot of powerpoint slides.  Far better to have the students find stuff out for themselves - it's much more likely to to stick in their heads then.  There are some things I get conflicted about - I'm a scientist, but I'm also a tree-hugger, own a pair of Birkenstock sandals and didn't send my kids to school.  One of the issues where I'm less certain than I'd like to be is fluoridation of the water-supply to prevent dental caries.  So I thought it would be good to crowd-source a solution to my F dilemma by hosting a debate on the matter.

As a first step, I surveyed my class as to their unprepared knee-jerk position on fluoridation, getting them to tick one box from
"Fluoridation of water is  . .": wonderful [ ] good [ ] dunno [ ] bad [ ] divil's spawn [ ]
Based on that, I divided the class into two cohorts pro-F and anti-F and told them they had a week to prepare their positions.  Last Thursday I bumped into one of my colleagues who said that she'd been asked for her opinion on the issue and reported that her questioner was quite passionately engaged in the project.

Earlier in the week we had the debate, which I lubricated with a box of chocolates - the irony of which was lost on me until the kids started to show grim pictures of carietic teeth.  Their material was well-researched and presented with good humor and cogent arguments.  Afterwards I resurveyed everyone as to their position.  The first finding was that the exercise had polarized opinion to the max, nobody was now anything less than certain about fluoride whereas before there had been several waverers.  I had to award the accolade to the anti-F people because they had shifted 3 opinions towards their position whereas the pro-F chaps had only dragged one person towards theirs.  I was particularly taken with two pieces of evidence that supported the anti-fluoridation position. One was that dental caries has fallen precipitously over the last 40 years both in countries that add fluoride to the water and those that don't. The other was that in Ireland we spend about €4 million a year adding fluoride to the water but that after leakage, industrial and agricultural consumption, car-washing, toilet flushing and bathing, only 0.1% of the processed drinking water is actually drunk. That seems grossly inefficient. So until I critically evaluate the quality of their sources and the statistical significance of their analysis, I confess to leaning towards anti-fluoridation.