Scientists at the University of California at San Diego and the nearby Veterans Affairs Medical Healthcare System in La Jolla recently concluded that magnetic nanoparticles may be hazardous to your health. Experiments revealed that iron oxide particles less than 10 nanometers in diameter stunt the growth of nerve cells. Separate in vitro experiments at the National Institute of Standards and Technology (NIST) have also concluded that nanotubes shorter than 200 nanometers interfere with human lung cells. Both groups called for animal testing that would not only quantify the toxic effects of nanomaterials on living organisms but also characterize the most toxic types of nanomaterials. Currently the National Science Foundation (NSF) spends almost 10 times more on developing nanomaterials than on engineering to prevent their toxic effects.