Dear All,

I want to alert everyone to a provocative and intriguing article in
July 2007 Consumer Reports about nanotechnology, which was used in $50
billion worth of goods in 2006.

Substances that are usually benign have different properties when they
are nano-sized. "Workers at one laboratory...did not know that some
nanoparticles are extremely combustible. So they were startled when a
rag that contained nanoparticle resides spontaneously burst into
flames."

A sidebar article on sunscreens says that all 8 lotions using zinc
oxide or titanium dioxide that were tested utilize nanoparticles. Only
one revealed that fact on the label. "Lab studies indicate that both of
those nanoingredients create free radicals that damage the DNA of cells
and possibly cause other harm as well. And even low exposure to
nonparticles of titanium dioxide can damage the lungs of animals if
inhaled."

These particles don't penetrate normal skin. However, "skin damaged by
acne, eczema, sunburn, or nicks from shaving is more vulnerable to
penetration" and these compounds have not been studied with such skin
conditions. Studies of other nanoparticles demonstrate that they can
enter "through hair follicles or when skin is repeatedly stretched."

Neutrogena Ultra Sheer Dry-Touch SPF 45 doesn't contain zinc oxide or
titanium dioxide.

The main article ranges over the many current and potential
applications of nanotech and discusses the possible benefits and risks
and FDA oversight (not much).

Here's a possibly shell-related aspect: "Recent studies have shown that
fullerenes, composed of spherically arranged carbon atoms, might damage
cells in fish, kill other aquatic micro-organisms, and harm human liver
cells and DNA."

David Kirsh
Durham, NC

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