CHAPEL HILL, N.C., Dec. 4 (UPI) -- Minuscule nanoparticles added to consumer products increasingly may be swarming through the body and threatening organs like the liver, U.S. scientists fear.
"The smaller a particle, the further it can travel through tissue, along airways or in blood vessels," Dr. Adnan Nasir, a clinical assistant professor of dermatology at the University of North Carolina at Chapel Hill, told The New York Times.
"Especially if the nanoparticles are indestructible and accumulate and are not metabolized, if you accumulate them in the organs, the organs could fail," he said.
Even when made of inert elements, nanomaterials take on unique properties, compared with their larger counterparts, due to their small size and large surface area, research suggests.
Animal studies indicate nanoparticles can penetrate cells and tissues, move through the body and brain and cause biochemical damage. They have also been linked to testicular cancer and cardiovascular system damage and may pose an environmental hazard, studies suggest.
Their use in lotions and creams -- particularly in mineral sunscreens -- has drawn the most critical attention, the Times said.
Consumer Reports magazine commissioned a study that found mineral nanoparticles in five sunscreens, even though four of the companies denied using them.
A separate study by the U.S. Commerce Department's National Institute of Standards and Technology found stoves and toaster ovens emit ultrafine particles of 2 to 30 nanometers.