In recent years, many communities in salmon country on the Pacific Coast have said “No” to community water fluoridation after considering the impact on fish and other creatures living in their waterways. With three endangered salmon species in Sonoma County, the purity of our rivers, creeks and streams is essential.
Our County Health Services Department is currently proposing to fluoridate our public water. This would mean injecting about 60 tons of fluoride chemicals into the water system every year. Because we drink less than 1% of our tap water, more than 99% goes straight down the drain, onto our lawns and gardens, into our sewers, and on our crops and fields. Much runs off into the creeks and waterways in which our fragile salmon species live and migrate.
To examine fluoridation’s potential impact on our fish, the County hired a consultant, Cardno Entrix, who presented their draft report to the County’s Fluoridation Advisory Committee. This committee will discuss the report at its upcoming December 8 meeting.
Unfortunately, the report, entitled Draft Assessment of Potential Impacts to Federally Listed Salmonids from Community Water Fluoridation in Sonoma County, contains a number of fundamental and disturbing deficiencies:
The report focuses on the wrong question and fails to deal with the real threat water fluoridation poses to our fish. The point of this aquatic assessment is to examine the range of risks fluoridation poses to Sonoma County’s fish and waterways. But the consultant focuses its investigation only on whether fluoride levels in our waterways could increase enough to kill or cause physiological changes in fish (this starts to happen at 4.4 parts per million, according to the report).
By limiting its focus to this issue, the consultant avoids grappling with the more realistic risk: Do elevated fluoride levels impact fish migration behavior, their food supply, and their ability to feed? And any changes in normal life cycle, reproduction behavior and the ability to migrate could threaten an entire species.
The Consultant fails to consider the only study that squarely addresses the harms to fish migration behavior posed by water fluoridation. The consultant acknowledged that it disregarded the well-known Damkaer & Dey study of 1989, which is the only study we are aware of that addresses the impact of fluoride levels on fish migration behavior.
According to the consultant, it excluded this study for several reasons, emphasizing the fact that “it has not been replicated.” This is not a scientifically legitimate reason to exclude a study that is directly on point. To our knowledge, there has been no attempt to replicate this study — and it may be worth noting that funding for fluoride research is notoriously hard to come by, unless the researcher is known to support water fluoridation.
The Damkaer & Dey study showed fish migration behavior is negatively impacted at fluoride levels as low as 0.2 and 0.5 parts per million, which would be exceeded if fluoridation is implemented. The consultant calculated that fluoride levels in Sonoma County’s fish habitat could reach as high as 0.7 ppm — well above the levels found by Damkaer & Dey to disorient fish.
The Consultant’s report does not address fluoridation’s impact on the food web that supports salmonids and amphibians: While the report cites research on the effects of fluoride on aquatic plants and invertebrates that feed our fish, this research is otherwise ignored. There are no conclusions or even comments on potential impacts. Many studies show harm to aquatic food sources from chronic low-level fluoride pollution. The failure to address this issue undermines the credibility of the report, and at the very least its thoroughness.
The report fails to address the potential for disruption or blocking of salmon migration in mixing zones. A mixing zone is an area where high concentrations of pollutants meet lower concentrations of freshwater flowing in a creek or river, resulting in pollutant levels much higher than otherwise permitted. The risk is that high fluoride levels within mixing zones could create ‘chemical fish barriers’ — effectively blocking salmon from migrating upstream to reproduce. Because the consultant did not address fish migration behavior, however, this very real concern is ignored.
Sonoma County’s hard water would not protect salmon from fluoride’s effects. Several pages of the report were devoted to the idea that our local hard water would mitigate the impact of higher fluoride levels.
Studies do show that when fluoride levels are high, harder water results in lower fish mortality. There is, however, no research we are aware of that shows that harder water lessens fluoride’s impact on fish migration behavior, which is the key issue in Sonoma County. Adverse physiological impacts on individual fish and impacts on fish migration behavior are two completely different considerations.
Freshwater fish habitat requires much lower fluoride levels than saltwater habitat. When the consultant presented the draft report, it noted that salmon are not harmed by fluoride levels as high as 1.0 ppm in seawater. This is true, and is a point frequently asserted by fluoridation advocates to calm concerns about fluoride levels in fresh water.
But the level of fluoride in seawater and fresh water is not an apples-to-apples comparison, because fish metabolism in seawater is quite different from fish metabolism in fresh water. Therefore, in assessing Sonoma County’s fresh water fish habitat, seawater fluoride concentrations are irrelevant.
The impacts of irrigating County farmlands with fluoridated wastewater are ignored. Here in Sonoma County, we commonly have water runoff not only from over-watering our yards, but also from over-watering urban parks and open spaces, and over-irrigating our crops and fields with the County’s wastewater. In fact, it has been well-documented by Brenda Adelman and others in Sonoma County that at some times of the year, much of the surface flow of many creeks in Sonoma County is due to run-off from farmland over-irrigation.
But while the consultant’s report mentions in its introduction that fluoridated wastewater would be used for both urban and farmland irrigation, it completely fails to evaluate or assess the impacts of the runoff from the farmland irrigation.
Who pays the cost of ongoing sampling and of removing fluoride from water to be stored in local aquifers? Two interventions required by fluoridation are mentioned in the report, though how much they will cost and who should pay those costs are not addressed:
Water sampling: the consultant recommends ongoing sampling if fluoridation is implemented.
Fluoride removal: The Sonoma County Water Agency is considering storing drinking water in County aquifers, which would require that fluoride (and chlorine) be removed prior to injection. This could be a major cost.
Conclusion: The Davis City Council and a majority of the voters of Portland and other communities living in salmon habitat on the Pacific Coast carefully considered the potential impact on fish when rejecting community water fluoridation. Can we afford to be any less cautious about these potential impacts on our three fragile salmon species and the food web that supports them?
When a report such as this fails to confront the difficult facts and risks, its credibility is dramatically undermined. From both an environmental policy and practical perspective, it would be irresponsible to push water fluoridation through in Sonoma County with only this flawed and incomplete draft report as our guide.
By Stephen Fuller-Rowell, M.A., Co-Founder of Fluoride-Free Sonoma County & Member of the Fluoridation Advisory Committee