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

[Links to posts in this series: Part 1, Part 2, Part 3, Part 4, Part 5]

In my last post, I decried EPA’s shortsighted decision to declare nano forms of chemicals listed on the Toxic Substances Control Act (TSCA) Inventory to be “existing” rather than “new” chemicals.  But I noted that EPA did not rule that all nanomaterials are existing chemicals.  EPA says it will consider buckyballs, carbon nanotubes, or anything else that has no counterpart – a substance with the same chemical structure – already on the TSCA Inventory to be “new.”  So can we rest assured that, at least for these nanomaterials, EPA has sufficient authority under TSCA to effectively identify and address their potential risks?  Would it were so.  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.

The history of health and environmental impacts of fuel additives is not a pretty one.  From tetra-ethyl lead to methyl tert-butyl ether (MTBE), we’ve learned the hard way that what goes in the tank ends up in our bodies and the environment sooner or later.  Getting a thorough understanding of the potential risks of a new fuel additive at an early stage is essential to avoid a lot of harm, suffering, and economic costs down the line. 

A new study by Park et al. has assessed the potential respiratory risks of a fuel additive called Envirox (nanoparticulate cerium oxide), giving it a clean bill of health based only on in vitro tests.  Is this the vision of the future of risk assessment?  Should we feel safe? Read more »