Daily Archives: February 21, 2013

Fluoride chemical study swats at a fly, but swallows a Camel

The presumption of this study, of course, is that there are no health risks associated with adding a fluoride chemical to drinking water, and thus the camel has been swallowed. Swatting the fly (impurities in the chemicals) is a side show….Of course, there is a more fundamental flaw in this study, which is a theoretical risk estimation as this does not represent real people. People are not a statistical category. It is incorrect to say that a water system that adds fluoride by switching chemicals will “reduce the number of lung and bladder cancers among their citizens.” The study estimates statistical cancers, not real cancer cases. Lastly, the study completely ignores the adverse impacts of adding additional fluoride exposure to the population via drinking water fluoridation. If fluoridation is eliminated altogether (which I support) then all of the impacts mentioned in this study as well as fluorosis and other negative health effects of the ingested fluoride would not occur at all, saving $$ billions.

J. William Hirzya, Robert J. Cartonb, Christina D. Bonannia, Carly M. Montaneroa, Michael F. Naglea. Comparison of hydrofluorosilicic acid and pharmaceutical sodium fluoride as fluoridating agents—A cost–benefit analysis. Environmental Science & Policy, Available online 16 February 2013

Water fluoridation programs in the United States and other countries which have them use either sodium fluoride (NaF), hydrofluorosilicic acid (HFSA) or the sodium salt of that acid (NaSF), all technical grade chemicals to adjust the fluoride level in drinking water to about 0.7–1 mg/L. In this paper we estimate the comparative overall cost for U.S. society between using cheaper industrial grade HFSA as the principal fluoridating agent versus using more costly pharmaceutical grade (U.S. Pharmacopeia – USP) NaF. USP NaF is used in toothpaste. HFSA, a liquid, contains significant amounts of arsenic (As). HFSA and NaSF have been shown to leach lead (Pb) from water delivery plumbing, while NaF has been shown not to do so. The U.S. Environmental Protection Agency’s (EPA) health-based drinking water standards for As and Pb are zero. Our focus was on comparing the social costs associated with the difference in numbers of cancer cases arising from As during use of HFSA as fluoridating agent versus substitution of USP grade NaF. We calculated the amount of As delivered to fluoridated water systems using each agent, and used EPA Unit Risk values for As to estimate the number of lung and bladder cancer cases associated with each. We used cost of cancer cases published by EPA to estimate cost of treating lung and bladder cancer cases. Commercial prices of HFSA and USP NaF were used to compare costs of using each to fluoridate. We then compared the total cost to our society for the use of HFSA versus USP NaF as fluoridating agent. The U.S. could save $1 billion to more than $5 billion/year by using USP NaF in place of HFSA while simultaneously mitigating the pain and suffering of citizens that result from use of the technical grade fluoridating agents. Other countries, such as Ireland, New Zealand, Canada and Australia that use technical grade fluoridating agents may realize similar benefits by making this change. Policy makers would have to confront the uneven distribution of costs and benefits across societies if this change were made.

Click here for full paper (fee).

Volatilization assessment drafted for chlorpyrifos exposure

The US Environmental Protection Agency (USEPA) has proposed an approach for assessing risks of spray drift from volatilized chlorpyrifos, a common agricultural insecticide.  Click here…..if adopted the approach could be applied to other pesticides……