Occupational Exposure to Airborne Nanomaterials: An Assessment of Worker Exposure to Aerosolised Metal Oxide Nanoparticles in Semiconductor Wastewater Treatment

This study characterised potential inhalation exposures of workers to nanometal oxides associated with industrial wastewater treatment processes in a semiconductor research and development facility. Exposure assessment methodology was designed to capture aerosolised engineered nanomaterials associated with the chemical mechanical planarisation wafer polishing process that were accessible for worker contact via inhalation in the on-site wastewater treatment facility. The research team conducted air sampling using a combination of filter-based capture methods for particle identification and characterisation and real-time direct-reading instruments for semi-quantitation of particle number concentration. Filter-based samples were analysed using electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling conducted over 14 months included 5 discrete sampling series events for 7 job tasks in coordination with on-site employees. The number of filter-based samples captured for analysis by electron microscopy was: 5 from personal breathing zone; 4 from task areas; and 3 from the background. Direct-reading instruments collected data for 5 sample collection periods in the task area and the background, and 2 extended background collection periods. Engineered nanomaterials of interest (Si, Al, Ce) were identified by electron microscopy in filter-based samples from all areas of collection, existing as agglomerates (>500nm) and nanoparticles (100nm-500nm). Particle counts showed an increase in number concentration during and after selected tasks above background. While additional data is needed to support further statistical analysis and determine trends, this initial investigation suggests that nanoparticles used or generated by chemical mechanical planarisation become aerosolised and may be accessible for inhalation exposures by workers in wastewater treatment facilities. the authors concluded that additional research is needed to further quantify the level of exposure and determine the potential human health impacts.

Authors: Brenner SA, Neu-Baker NM, Caglayan C, Zurbenko IG. ;Full Source: Journal of Occupational & Environmental Hygiene. 2015 Mar 4:0. [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][Epub ahead of print] ;[/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]