Nova Scotia doctors Robert Strang, Daniela Kempkens and Ferne Kraglund co-authored a response on June 22 to my op-ed article which appeared in the Cape Breton Post on May 28.

In it, they criticize recently published studies linking fluoride exposures with increased risk of damage to the developing brain during pregnancy and reduced thyroid function in iodine-deficient adults. Unfortunately, but not unexpectedly, the doctors fail to provide any primary studies to refute these findings.

In 2017, a rigorous 12-year, United States government-funded study published in ‘Environmental Health Perspectives’, concluded that higher urinary fluoride levels in pregnant women in Mexico City were associated with reduced IQ in children. This study (Bashash et al. 2017) was carried out by a team of leading researchers from Canada, the U.S. and Mexico.

The same team of experts then conducted a follow-up study on ADHD (Bashash et al. 2018) which found that higher urinary fluoride levels during pregnancy were also associated with more ADHD-like symptoms in children.

Yet the doctors suggest that the results of these high quality studies should not be applied in our fluoridated communities, due mainly to the sources of fluoride the study’s participants were exposed to. But researchers measured urinary fluoride levels, which is a measure of ALL sources of fluoride. They also controlled for many potential factors including socio-economic status, lead, mercury, smoking history, etc.

This next published study, led by York University researchers, found that pregnant women living in fluoridated Canadian communities had urinary fluoride levels that were twice as high as those in non-fluoridated communities. (Till et al. 2018) Most concerning is that these higher maternal fluoride levels were similar to those associated with lowered intelligence and increased ADHD symptoms in children in the Bashash studies.

Clearly the findings of the Bashash studies are relevant here in our fluoridated communities and Public Health should have taken action to protect our most vulnerable from fluoride exposure. Given that there has been very little research on the effects of fluoride exposure during pregnancy on the developing brain, what studies could Public Health possibly be relying on to refute the Bashash findings?

Adding to this, a recently published study found that higher urinary fluoride levels in Canadian adults increased the risk of underactive thyroid among those who were iodine deficient. (Malin et al. 2018) These results were observed even though those most at risk were excluded from the study, including pregnant women and adults taking medication for a pre-existing thyroid condition.

Also, the majority of participants studied were exposed to lower levels of fluoride in their drinking water than those living in fluoridated communities would be exposed to. All of these factors would contribute to underestimating the association between fluoride and thyroid function.

How could this not be of public health importance, especially when 18 per cent of the population in this study was found to be moderately-to-severely iodine deficient? Where are the primary studies to refute these findings?

The doctors also claim, “Community water fluoridation in Nova Scotia is controlled and monitored.” What they failed to add is that this only happens at the water utility. Once the fluoridation chemical, hydrofluorosilicic acid, is added to the drinking water, the dose to each individual cannot be controlled. Also, Public Health is not monitoring our individual exposure from all sources of fluoride – a toxic substance known to cause harm. Dental fluorosis, permanent damage to the teeth, is a visible indicator of that harm, and according to the Canadian Dental Association, rates of dental fluorosis are increasing.

While the doctors say they are relying on “conclusive evidence,” when touting the safety of water fluoridation, they never provide any primary studies to support that. I asked Dr. Strang and others for those studies almost 10 years ago and I’m still waiting.

Cape Breton Regional Municipality council can vote to end water fluoridation to protect all residents.

Marlene Kane
Sydney

*Original letter online at https://www.capebretonpost.com/opinion/letter-to-the-editor/letter-to-the-editor-water-fluoridation-debate-continues-339325/