From an article by Olga Naidenko, Environmental Working Group Senior Scientist
American water utilities are increasingly switching to chloramines, a mixture of chlorine and ammonia, for final disinfection of drinking water. Chloramine was supposed to be a "safer" water disinfectant than chlorine because it reduces formation of toxic chlorination byproducts. A 2005 survey by the American Water Works Association found that approximately a third of all utilities now use chloramines. Water disinfection byproducts are associated with increased risk of cancer and possibly adverse effects on the development of the fetus, so minimizing their levels in drinking water is a good thing. Yet, chloramines drastically increase the leaching of lead from pipes.
Two thirds of the U.S. municipal water supply is artificially fluoridated in an effort to prevent tooth decay. But fluoridation additives in tap water are not the same form of fluoride as found in toothpaste. Typically, water is fluoridated with fluorosilicic acid (FSA) or its salt, sodium fluosilicate, collectively referred to as fluorosilicates. In contrast, fluoride in toothpaste is usually in form of simple sodium fluoride salt, NaF.
Fluorosilicates have a unique affinity for lead. In fact, lead fluorosilicate is one of the most water-soluble forms of lead. When fluorosilicates in water pass through lead-containing pipes and metal fixtures, the fluorosilicates extract high levels of soluble lead from leaded-brass metal parts. Researchers have found that the mixture of the two chemicals: disinfectant (whether chlorine or chloramine) with fluorosilicic acid has a drastically increased potency, leaching amazingly high quantities of lead. This lead goes into our drinking water and right on into our bodies, where they wreak havoc by poisoning our heart, kidneys and blood, causing irreversible neurological damage and impairing reproductive function.
Chlorine and chloramine are probably here to stay for some time. On the other hand, fluoride, or, specifically, water fluoridation with fluorosilicates, is quite dispensable. There is clear evidence that fluoride dental products significantly reduce the incidence of cavities. In contrast, a substantial and growing body of peer-reviewed science suggests that ingesting fluoride in tap water does not provide any additional dental benefits other than those offered by fluoride toothpaste and may present serious health risks.
In case of fluoridation and chloramines, what emerges at the end of the pipe (our faucets) is a potentially highly hazardous mixture of fluorosilicates, lead, and residual levels of disinfectants. To protect the health of our families today, we can buy a water filters to remove heavy metals and disinfection byproducts from my drinking water with a simple pitcher filter.
Water treatment chemistry is still insufficiently understood by scientists and specific water quality outcomes depend on the particular chemical interactions found in each water treatment and distribution system. To protect the health of the entire nation, we really need to consider if our current methods of water treatment can withstand scientific scrutiny, or whether they should be re-assessed so as to provide safe, healthy tap water to all Americans. (EWG EnviroBlog, 7/13/2009)
No comments:
Post a Comment