Nanoparticle Release in Indoor Workplaces: Emission Sources, Release Determinants and Release Categories Based on Workplace Measurements

Abstract

Materials with one or more dimensions at nanosized scale have different properties from their larger physical forms; thus, they may interact differently with environmental and biological systems. However, the traditional risk assessment methodology (release/exposure assessment, hazard identification, hazard and risk characterisation) is not yet fully understood or has clear guidelines about the appropriate testing procedure for nanoparticles. Although exposure to NPs is being more widely characterised, mechanisms to determine the likelihood of release and transport of NPs in the workplace are still very scarce. Four main sources or domains for release have been identified: punctual or fugitive emissions, handling of bulk material at low energy, dispersion of highly concentrated NPs or application of end products with low concentration on NPs and abrasion or fracturing activities (high energy). To determine the release of NPs, an understanding of the release potential, appropriate metrics and measurement strategies and adequate instrumentation and identification of the potential sources of emission are fundamental. Several studies try to establish a methodology; thus, thorough review and intercomparison have been accomplished. Also, data retrieved from field measurements were analysed, showing that particle concentrations at 250 nm increased compared to background particles, occurring episodes of elevated particle number concentrations below 100 nm, although it was not clear whether this was associated with handling of and/or mixing operations or external sources to the process.C. Fito-L opez (*) and M. Domat-Rodriguez Packaging,