Every so many years someone tries to publish a review (or narrative) of the history of fluoridation. Recently I read such a review:
Title:Fluoride Is Introduced into the U.S. Water Supply. By: Thomas, Nicholas C., Salem Press Encyclopedia, January, 2013 Database:Research Starters
Like other narratives, this review tells the saga of Frederick McKay, Harry Churchill, and H. Trendy Dean. And like other reviews it fails to mention that the US Public Health Service for whom Dean worked was an agency in need of a permanent place within the government as well as more congressional funding. (Sound familiar?) The 1930s and 1940s were a time when doing good things for people was used to promote government program expansion. The political agendas associated with Dean’s work and the Grand Rapids study are never acknowledged. My intent is not to cast suspicion or to say that something wrong was done. My point is that the fairytale history of fluoridation presented by government agencies airbrush out the political agendas of the times which are just as important in understanding current day attitudes.
Lastly, this particular review concludes with the following paragraph:
“The fluoridation issue demonstrated how scientific debate can be influenced by political and social policies and pressures. Neither proponents nor opponents of the fluoridation issue have been consistently objective in the analysis of their scientific findings. Only unbiased scientific research can adequately attempt to measure the potential toxicity of low levels of fluoridated water. For more than half a century, the scientific community has been unable to reach a consensus on the toxicity of fluoridated water.”
This is very odd. The article author claims that only “unbiased scientific research” can answer the question of low level fluoride toxicity. Yet, on what basis does the author (Nicholas C. Thomas) believe he is in a position to judge that all research so far on low levels of fluoride are biased? Has Mr. Thomas read all of the research papers to determine which ones are biased? Of course, intentional bias by government scientists needing congressional funding and blind advocacy by “fluoride activists” muddy the waters even more. This review simply plays one side against the other and then concludes there is no agreement, which is to say it is no review at all. Mr. Thomas has simply skipped over any serious thinking on this issue.
I am not much of a fan of studies based on tree-ring analysis because previous studies have shown that “reading tree rings” is unreliable. But if they are going to be used then the dendochrologists need to compare notes more often. The study below appears to be much more robust than the studies generating all the fuss over a supposed “hockey stick.”
Feng Chen, Yujiang Yuan, Ruibo Zhang, Li Qin. A tree-ring based drought reconstruction (AD 1760–2010) for the Loess Plateau and its possible driving mechanisms. Global and Planetary Change
We have developed a 272-year ring-width chronology of Chinese pine (Pinus tabulaeformis) growing in the Huanglong Mountains, North China. Climatic response analyses revealed that mean January-July Palmer drought severity index (PDSI) has positive effect on the radial growth of pine trees. Based on the relationships, the mean January-July PDSI was reconstructed for the period from 1760 to 2010. The percentage of variance in the data explained by the reconstruction was 41% during the calibration period of 1950–2010. Spatial correlation analyses between the PDSI reconstruction and gridded PDSI data shows that the PDSI reconstruction captures regional drought variations over the environmentally-sensitive area linked to the East Asian summer monsoon. Relatively wet periods are identified for AD 1766–1781, 1795–1804, 1811–1821, 1838–1859, 1884–1889, 1909–1914, 1937–1977 and 2003–2008. Dry conditions prevailed during AD 1760–1765, 1782–1794, 1805–1810, 1822–1837, 1860–1883, 1890–1908, 1915–1936, 1978–2002 and 2009–now. There is a reasonable agreement with dry/wet periods previously estimated from tree-ring data of the Kongtong Mountains of the Loess Plateau. Spatial correlation analyses with sea surface temperature in the Pacific Ocean and tropical Indian Ocean indicated that the Asian summer monsoon circulations play a role in modulating drought variations in the study area whereas the effects of the Pacific Decadal Oscillation are relatively strong.
Click here for full paper (fee).
Posted in Climate
When a large populated area such as the San Francisco Bay area cannot afford to maintain or replace large projects like the Hetch-Hetchy water tunnel, then such infrastructure is unsustainable. These are large political pork projects….but even so they must be maintained and replaced eventually. They do not last forever and eventually will fall apart. No surprises there.
“City officials have known for 25 years that significant work is needed on the 19-mile-long tunnel just outside Yosemite National Park in a steep, hard-to-access wilderness area. They considered making it part of the PUC‘s decade-old, $4.6 billion water system improvement program, which is now more than 80 percent complete. But ultimately, the 89-year-old connector was left out of the rebuild, which focused on upgrading Bay Area water facilities that could fail in an earthquake.” click here
Every few years young researchers new to field publish articles that rehash old arguments. This certainly seems to be the case with regard to arsenic. This paper repeats the same claims made in the 1990s and the lowering of the MCL in the US. Arsenic has been kicked around so much over the last 20 years that to go back to the future to address this all over again is a huge waste of time and resources.
Sébastien Sauvé. Time to revisit arsenic regulations: comparing drinking water and rice. BMC Public Health 2014, :465 doi:10.1186/1471-2458-14-465
Background: Current arsenic regulations focus on drinking water without due consideration for dietary uptake and thus seem incoherent with respect to the risks arising from rice consumption. Existing arsenic guidelines are a cost-benefit compromise and, as such, they should be periodically re-evaluated.
Discussion: Literature data was used to compare arsenic exposure from rice consumption relative to exposure arising from drinking water. Standard risk assessment paradigms show that arsenic regulations for drinking water should target a maximum concentration of nearly zero to prevent excessive lung and bladder cancer risks (among others). A feasibility threshold of 3 μg As l−1 was determined, but a cost-benefit analysis concluded that it would be too expensive to target a threshold below 10 μg As l−1. Data from the literature was used to compare exposure to arsenic from rice and rice product consumption relative to drinking water consumption. The exposure to arsenic from rice consumption can easily be equivalent to or greater than drinking water exposure that already exceeds standard risks and is based on feasibility and cost-benefit compromises. It must also be emphasized that many may disagree with the implications for their own health given the abnormally high cancer odds expected at the cost-benefit arsenic threshold.
Summary: Tighter drinking water quality criteria should be implemented to properly protect people from excessive cancer risks. Food safety regulations must be put in place to prevent higher concentrations of arsenic in various drinks than those allowed in drinking water. Arsenic concentrations in rice should be regulated so as to roughly equate the risks and exposure levels observed from drinking water.