ENGINEERED NANOPARTICLES ARE SO SMALL THAT THEY ARE ESSENTIALLY SURFACES. THEY BEHAVE DIFFERENTLY IN THE BODY THAN OTHER NATURALLY OCCURRING SMALL PARTICLES, COMPLICATING RESEARCH. NEVERTHELESS, SERIOUS HEALTH CONSEQUENCES HAVE BEEN NOTED.

ADVERSE EFFECTS

Lung autophagy increased Pulmonary granulomas, fibrosis, tumors Free radical damage Lung inflammation Metal toxicity from components More persistent than other toxins Effects not linked to mass of product Toxic effect on heart Toxic effect on reproductive system Toxic effect on kidneys Neurobehavioral changes Neurotoxic effects Genotoxic effect

Nonetheless, several studies exist on the toxicological properties of nanoparticles. Although the various toxicological aspects and the diversity of the nanomaterials assessed are just beginning, many deleterious effects have been documented, particularly in animals. Insoluble or low solubility nanoparticles are the greatest cause for concern. Several studies have shown that some of them can pass through the various protective barriers of living organisms. The inhaled nanoparticles can end up in the bloodstream after passing through all the respiratory or gastrointestinal protective mechanisms. They are then distributed in the various organs and accumulate at specific sites. They can travel along the olfactory nerves and penetrate directly into the brain, just as they can pass through cell barriers. These properties, extensively studied in pharmacology, could allow organic nanoparticles to be used as vectors to carry medications to targeted body sites. The corollary is that undesirable nanoparticles could be distributed throughout the body of exposed workers. Some of these nanoparticles have shown major toxic effects.

Another special feature of nanoparticles is that their toxicity seems to be linked to their surface. This is a major difference from the usual situations, in which toxicity is normally linked to a product’s mass. Nanoparticles are so tiny that small quantities (expressed in terms of mass), could have major toxic effects, because of their large surface. Several studies show much greater toxic effects for the same mass of nanoparticles as compared to the same product with a higher granulometry.