Re: Republicans Are Insane, Pathetic, Dishonest


Dave wrote:

Interesting:
Arsenic 10 parts per billion
Lead 15 parts per billion.

Fluoride is intermediate in toxicity between lead and arsenic. (Clinical Toxicology of
Commercial Products LD50 data (1984)

Permissible level of fluoride in water currently 4000 parts per billion.

Not much wonder the NRC has in the last couple of weeks recommended this level be
lowered as well. With the most common source of fluoride frequently contributing
additional arsenic to water supplies, maybe we'll see a closer look at that, too.

The LD50 for a given chemical (the Lethal Dose of a given chemical that
kills 50% of (usually) lab rats via quick "acute exposure") tells only
part of the chemical's toxicity, and the LD50 is of little value in
assessing relative toxicities in the drinking water scenario, where we
are talking about toxicological effects from low-level, "chronic
exposures" to humans via long term exposure from drinking water. In
this relatively low-level "chronic exposure" scenario lead and arsenic,
unlike flouride, have both been clearly demonstrated to cause
physiological damage in humans, such as neurological damage. This is
why the MCLs (Maximum Contaminent Levels) for lead and arsenic in
drinking water are so much lower than the MCL is for flouride.

Ray

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