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Report on
Fluoridation Experiment
by Sejla Alimanovic
The artificial addition of fluoride to drinking water has
challenged countless scientists and questioned many
governments. It was in July of 2003 that I was introduced to
independent study in Environmental Chemistry. The class involved an
introductory course concerning many environmental issues and themes, such as
CO2 production, pollution, ozone
layer, salinity, and water quality, to name a few. The first term consisted
of teacher directed learning, whereas the second term consisted of student
directed work. That is, we had to choose an environmental issue, research it
in depth, and develop and conduct analytical chemistry experiments to come
to a conclusion about the issue. This is where the fluoridation of drinking
water intrigued me.
I began to research the issue and soon found myself in a very
aggravated state, wanting to do something about it, and needing many
questions answered. Questions such as, what is the
real
reason for the addition of fluoride to water? Why has no
scientific evidence been gathered to prove fluoride safe, when many
countries all over the world were being fed this chemical in many different
ways (one of which is through water)? Why was it impossible to find answers?
Because they did not exist! Much to my horror, I had discovered that no
official concrete evidence existed to prove that artificial fluoridation of
water was safe! Something had to be done.
I decided to grow some fast growing Brassica plants (the
Brassica species includes Cabbage and Turnip) that were obtained from the
CSIRO, water them with increasing concentrations of fluoridated water,
observe any disfigurements, and finally conduct analytical experiments to
measure the amount or accumulated fluoride in the plants. The first few
experiments such as planting, watering and drying the plants were
straightforward. However, measuring the amount of fluoride ions that had
accumulated in each set of plants proved to be somewhat more complicated.
The following table shows the concentrations in each punnet, starting from 1
ppm, which was the control of the experiment.
The plants were dried, weighed to a controlled amount, and
boiled in a special solution. The solution used was called a Total Ionic
Strength Adjustment Buffer (TISAB). This solution was used to maintain a
constant pH, a constant ionic strength and to remove all metal ions, which
may interfere with the electrode reaction (i.e. A13+, Fe3+).
The TISAB consisted of the following and had a pH of 5.0, and an ionic
strength of 1.75M.
| Volumetric Flask |
Concentration of
fluoride added (mL) |
Part/Million |
| Control |
19.2 |
1 |
| Double |
38.4 |
2 |
| Double and a Half |
48.0 |
2.5 |
| Triple |
57.6 |
3 |
| Triple and a Half |
67.3 |
3.5 |
| |
|
|
| Substance |
Molarity (M) |
Purpose of Substance in
TISAB |
| Sodium Chloride |
1M |
Electrolyte |
| Sodium Acetate |
0.75M |
Buffer |
| Acetic Acid |
0.25M |
Buffer |
| Sodium Citrate |
0.001M |
Removes Fe(III) or A1
(III) as soluble complexes |
After the plants were boiled in the TISAB, and filtered to remove any plant
residue, a process called potentiometry was used to calculate the amount of
fluoride ions in each plant sample. This process is very similar to that of
a galvanic cell set up, the only difference being that there was one cell,
i.e. the Cell consisted of one beaker in which both of the electrodes were
placed. The beaker first contained a Sodium Fluoride (NaF) solution, in
order to prepare a calibration graph. The NaF was prepared
in different
concentrations, and therefore had different readings. (The concentration
becomes the x-axis of the graph and the reading becomes the y-axis of the
graph). From this calibration graph, and concentrations were derived in
micrograms of F-1/gram
of sample. The electrodes used in the potentiometer were a silver cathode
and a chloride anode. The electrodes were attached to a pH meter and the
potentiometer was ready for use. This procedure should isolate the fluoride
ion as the only factor which changes the acidity of the solution being
tested and shows the change in the concentration of fluoride in the test
samples.
The plants were found to accumulate the
fluoride during their short lifespan.
The results that were found confirmed my
expectations. The plants were found to accumulate the fluoride during their
short lifespan. The plants absorbed the water, along with the fluoride ions,
into their biological systems, it was concluded that the plants could not
excrete the fluoride. Close observations were recorded throughout the time
that the plants were growing, and the plants with the higher concentrations
of fluoride were found to have some physiological defects, such as loss in
lush green colour that was observed in the control yellow spots developed on
some leaves, and some plants were shorter than the control, i.e. cell
elongation was constrained.
It can be seen that there is an increasing
trend for accumulation of fluoride in the Brassica plant as the
concentration of fluoride in the water increases, and according to these
results, it can be concluded that fluoridation is unsafe. However, in
retrospect, a lot of adjustments can be made to this research project in
order to further validate this conclusion. For example, the water that the
fluoridated solution was diluted with should not have been distilled. That
is, the water coming from our taps has other minerals and dissolved
substances in it that would also greatly affect the fluoride content in our
tap water. The technique used for detecting fluoride ions is somewhat dated,
since more modern equipment was not available to me. The list of small
adjustments is usually always endless, and that is why numerous experiments
and reports need to be conducted in order to conclusively prove the possible
danger of the artificial fluoridation of drinking water. As I have learned
in my few years of scientific experience, it is not humanly possible to
conduct an experiment without error. Error is always present, meaning
we (scientists) must conduct endless experiments in order to come to some
kind of an average or overall conclusion. One thing is for sure; not enough
has been done to prove fluoridation safe. This applies for all fluoridated
products, such as toothpastes, mouthwashes etc., because all of these
factors contribute to the accumulated fluoride in our bodies. People should
be given a choice in this matter; we should be able to choose what kind of
harsh chemicals (the fluoride in tap water is actually an unrefined
industrial by-product) are added to our tap water. After all, are we or are
we not living in a democratic country?
Sejla Alimanovic is a teenage student in
Melbourne - Editor.
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