Richard Denison, Ph.D., is a Senior Scientist.

Some months ago, my colleague John Balbus posted here about studies finding that when multi-walled carbon nanotubes (MWCNTs) are injected into the abdominal cavities of mice, they induce inflammation and mesothelioma-like reactions similar to those caused by asbestos.  He appropriately cautioned that – among other critical questions – these studies had not demonstrated that inhaled MWCNTs could actually move out of the lung and into the tissues where asbestos gives rise to its effects.  Well, that particular dot now appears to have been connected. Read more »

Richard Denison, Ph.D., is a Senior Scientist.

In some nanotechnology circles, it is almost a mantra that, once released to the environment, nanoparticles will inevitably aggregate or agglomerate into larger masses and thereby lose their nanoscale-related properties and, by implication at least, any associated risks.

But can we count on nanoparticles released to the environment to self-regulate their own risk so conveniently? Read more »

Richard Denison, Ph.D., is a Senior Scientist.

Section 8(e) of the Toxic Substances Control Act (TSCA) requires any company that manufactures, imports, processes or distributes chemicals in the U.S. to notify EPA within 30 days if it obtains new information that "reasonably supports the conclusion that such substance or mixture presents a substantial risk of injury to health or the environment."  Are there Section 8(e) notices for nanomaterials? Read more »

Cal Baier-Anderson, Ph.D., is a Health Scientist.

The manufacture of carbon nanotubes (CNTs) is a very complicated business.  Different production processes leave behind different kinds of metal catalysts, which yield differences in physical and chemical – as well as toxicological – properties of the CNTs.  Read more »

Richard Denison, Ph.D., is a Senior Scientist.

The insurance industry is out in front on nanotechnology yet again.  As the giant reinsurer Swiss Re did way back in May 2004 with its groundbreaking report Nanotechnology: Small matter, many unknowns, it is once again the insurance industry sounding an early alarm about nanomaterials.  In this case, it's the Continental Western Insurance Group (CWG), which has just announced that it will exclude coverage for "the, as of yet, unknown and unknowable risks created by the products and processes that involve nanotubes." Read more »

John Balbus, M.D., M.P.H., is Chief Health Scientist.

A new paper by Shaw et al., published in May in the Proceedings of the National Academy of Sciences, “suggests a generalizable and scalable method for the systematic characterization and comparison of novel nanomaterials” using high throughput in vitro tests.  Does this mean that the National Academy of Sciences’ vision for toxicity testing in the 21st century – proposed for conventional chemicals – is already here for nanomaterials?  Not quite.  Read more »

Cal Baier-Anderson, Ph.D., is a Health Scientist.

The proliferation of nanoscale materials in consumer products is impressive:  nano titanium dioxide and zinc oxide in sunscreen, buckyballs in face creams, and nanosilver in socks are but a few examples of what is currently available for purchase.  But they make me wonder:  what happens when the nanomaterials in or released from these products are washed down the drain?   Read more »

John Balbus, M.D., M.P.H., is Chief Health Scientist.

A new study published today in Nature Nanotechnology finds that multi-walled carbon nanotubes (MWCNTs) cause inflammatory changes in mice that closely resemble those caused by asbestos.  This is the second study in a few months to make this finding.  (I posted on the first, Takagi et al., a few weeks ago.)  So is the case closed on multi-walled carbon nanotubes?  Or is too early to draw conclusions? Read more »

John Balbus, M.D., M.P.H., is Chief Health Scientist.

We and many others have made analogies between nanoparticles and asbestos.  The purpose of the analogy has generally been to emphasize the long latency that can occur between exposure to toxic materials and the development and subsequent recognition of disease arising from that exposure.  And, of course, the enormous legal and financial burden of failing to adequately consider risks before allowing widespread exposure.  But a new study suggests that the analogy may be even stronger than we thought:  It may extend to the capacity to cause mesothelioma, the rare form of cancer associated with exposure to asbestos. Read more »

Cal Baier-Anderson, Ph.D., is a Health Scientist.

After posting to this blog the other day, I came across a brand new study characterizing the heterogeneity of carbon nanotubes.  The authors of this study looked at 11 single-wall carbon nanotubes (SWCNTs) from 10 different suppliers and found that SWCNT composition varies dramatically depending on synthesis method, feedstock, purification steps, and other factors.  Read more »