Candace Su-Jung Tsai, Birck Nanotechnology Center and School of Health Science, Purdue University, West Lafayette, Indiana
Researchers investigated nanomaterial release associated with the contamination of protective clothing during manipulation of clothing fabrics contaminated with nanoparticles. Nanomaterials, when released as airborne nanoparticles, can cause inhalation exposure, which is the route of exposure of most concern to cause adverse health effects. Measurement of such nanoparticle re-suspension has not yet been conducted. Protective clothing can be contaminated with airborne nanoparticles during handling and operating processes, typically on the arms and front of the body. The contaminated clothing could release nanoparticles in the general room while performing other activities and manipulating the clothing after work. The exposures associated with three different fabric materials of contaminated laboratory coats (cotton, polyester and Tyvek), including the magnitude of contamination and particle release, were investigated in this study by measuring the number concentration increase and the weight change on fabric pieces. This study simulated real-life occupational-exposure scenarios and was performed in both regular and clean-room environments to investigate the effect of background aerosols on the measurements. Concentrations were measured using particle spectrometers for diameters from 10 nm to 10 µm. Collected aerosol particles and contaminated fabric surfaces were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental composition analysis. The magnitude of particle release from contaminated lab-coat fabric was found to vary by the type of fabric material; cotton fabric showed the highest level of contamination and particle release, followed by Tyvek and polyester fabrics. The polyester lab-coat material was found to have the lowest particle-release-to-deposition (R/D) ratio. The particle-release-number concentrations were in a range of 768-119 particles cm−3 and 586-187 particles cm−3 in regular and clean rooms, respectively. Multiple peaks were observed in the number concentration distribution data, with particle diameters peaking at 40-50 and 100-300 nm. The SEM analysis of the contaminated fabric surface found test particles and other environmental particles. The elemental-composition analysis presented detectable response to the studied alumina-oxide particles. The laboratory coat primarily made of cotton woven material is not recommended for worker protection against nanoparticle exposure because of the highest particle contamination and release ability. In addition, the result demonstrated that a well-controlled (clean room) environment is critical to investigate the factors affecting nanoparticle interaction with protective clothing.
Ann Occ Hygiene, Volume 59, Issue 4, pages 491-503. Correspondence to: Candace Su-Jung Tsai, Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, Indiana 47907; tel: (765) 494-4676; fax: (765) 496-1377; email: tsai51@purdue.edu.