A Study of Protective Clothing to Prevent Nanoparticle Exposure and Surface Contamination Principal Investigator: Candace Su-Jung Tsai, Sc.D., Assistant Professor of Industrial Hygiene and Environmental Health, Colorado State University, and Faculty Member at Birck Nanotechnology Center, Purdue University Investigators: Yan Vivian Li, PhD., Assistant Professor in Fiber Science, Colorado State University Ron Reifenberger, PhD., Professor of Physics, Director of Kevin Hall Nanometrology Laboratory, Purdue University PROJECT SUMMARY The proliferation of new applications in nanotechnology has highlighted the need to protect researchers in laboratories and workers in production facilities from exposure to engineered nanoparticles (ENPs) through skin contact or inhalation. Workers wearing contaminated clothing are at high risk of inhaling ENPs released from that clothing without any awareness of the potential danger. We have recently documented the significant release of metal oxide ENPs from laboratory clothing and highlighted serious concerns regarding the need to better understand the factors associated with ENP exposure from workplace attire. Importantly, when leaving the laboratory/production line, researchers and workers are unaware of the possible ENP exposure from contaminated clothing that they bring back to the office, home or public places. This contaminated clothing also poses a significant risk to non-workers in these outside of the workplace settings. It is well documented in the past, for example, that exposure to asbestos fibers from contaminated clothing has caused many workers and non-workers to suffer from asbestos-related diseases. It is worrying to note that ENPs are 1/10 to 1/100 the size of asbestos particles. Thus, the number of exposed ENPs could be >1000 more than that of such micron asbestos fibers, yet they are still invisible to the human eye. The goal of this study is to address key knowledge gaps in our understanding of ENP contamination of laboratory protective clothing and identify ways to prevent and minimize the problem. To achieve this goal, this project will study the propensity for contamination of major protective clothing fabrics by clinically-significant ENPs as well as the potential for subsequent exposure to individuals who come into contact with these fabrics. Our study will focus on key mechanistic aspects of ENP-fabric interactions such as mechanical force and electrical charge. The quantitative assessment of ENP adhesion and release from contaminated clothing will allow us to identify optimal fabric characteristics for protection against toxic ENPs. Importantly, we will use novel sampling techniques and state of the art technologies, including direct-reading air monitoring instruments, a nanoparticle sampler possessing a proprietary modification that we made to improve performance, and a thermal precipitator designed for nanoparticle collection to determine exposure, and advanced microscopic analysis - including atomic force microscopy (AFM) to investigate the mechanical forces and electrical charges associated with ENP-fabric interactions. Practically, we will use plasma surface treatment to functionalize fabric fiber surface to improve surface properties.
An important but understudied route for exposure to engineered nanoparticles is from the contamination on laboratory coats and other personal protective equipment. This project will evaluate the major types of protective laboratory fabrics in terms of propensity for nanoparticle exposure and penetration. Our goal is to determine the exposure and physical mechanisms underlying nanoparticle adhesion and release from fabrics in order to ultimately develop improved fabrics with optimal surface properties for better worker protection.