L. Calderon, H-J Oh, G. Mainelis
Keywords: nanoparticles, clothing, silver, particle release, exposure
Summary:Nanotechnology is increasingly being used by the textile and clothing industry to give fabrics and clothing the desired performance, such as antimicrobial properties, resistance to stains and wrinkles, and even protection against electromagnetic waves. These properties are achieved by manipulating the fabric at the nano level or by incorporating manufactured nanoparticles, including metal nanoparticles into the fabric and clothing items. Since clothing gradually deteriorates during daily wear and handling, such as washing, the matrix holding the nanoparticles deteriorates as well leading to an increased possibility that the nanoparticles will be released into the wash water or air. Due to concerns regarding the health effects due to exposure to manufactured nanoparticles, this research evaluated the release of nanoparticles from nanotechnology-enabled clothing items during simulated clothing wear, with special emphasis on changes in particle release due to washing. We examined six clothing products that were produced using Nanotex® technology and eleven products that had silver nanoparticles or silver nanofibers in their structure. Clothing wear was simulated using an abrader, where the rotating clothing samples came in contact with felt abrader wheels. The released particles from new and washed items were measured using a Scanning Mobility Particle Sizer (SMPS) and Aerodynamic Particle Sizer (APS) and examined in terms of count and mass distribution and concentration. The concentration of metals in the fabrics was examined using inductively coupled plasma mass spectrometry (ICP-MS), while the morphology and composition of released particles were analyzed using TEM and SEM/EDX, respectively. We observed the release of nano-sized particles as well as larger agglomerates from all investigated products at different concentrations depending on a product. Silver was detected in most products at concentrations from 1 ppm to 1.5x10^5 ppm. The presence of silver was confirmed in the released particles as well. The released particle mass varied from 100 to 10,000 ng/m^3 and generally decreased after washing. The decrease was most pronounced for silver-containing products, where the number and mass concentration of particles larger than 0.5 µm generally decreased by approximately an order of magnitude. The release of particles smaller than 200 nm was much less affected. This work shows that nanoparticles and their agglomerates could be released from clothing during wear and potentially inhaled. The extent of exposure depends on a particular item and the deterioration of its matrix due to daily handling.