title: Occupational Exposure to Nano-Objects and Their Agglomerates and Aggregates Across Various Life Cycle Stages; A Broad-Scale Exposure Study.
abstract: BACKGROUND
  Occupational exposure to manufactured nano-objects and their agglomerates, and aggregates (NOAA) has been described in several workplace air monitoring studies. However, data pooling for general conclusions and exposure estimates are hampered by limited exposure data across the occupational life cycle of NOAA and a lack in comparability between the methods of collecting and analysing the data. By applying a consistent method of collecting and analysing the workplace exposure data, this study aimed to provide information about the occupational NOAA exposure levels across various life cycle stages of NOAA in the Netherlands which can also be used for multi-purpose use.
  
  
  METHODS
  Personal/near field task-based exposure data was collected using a multi-source exposure assessment method collecting real time particle number concentration, particle size distribution (PSD), filter-based samples for morphological, and elemental analysis and detailed contextual information. A decision logic was followed allowing a consistent and objective way of analysing the exposure data.
  
  
  RESULTS
  In total, 46 measurement surveys were conducted at 15 companies covering 18 different exposure situations across various occupational life cycle stages of NOAA. Highest activity-effect levels were found during replacement of big bags (<1000-76000 # cm(-3)), mixing/dumping of powders manually (<1000-52000 # cm(-3)) and mechanically (<1000-100000 # cm(-3)), and spraying of liquid (2000-800000 # cm(-3)) showing a high variability between and within the various exposure situations. In general, a limited change in PSD was found during the activity compared to the background.
  
  
  CONCLUSIONS
  This broad-scale exposure study gives a comprehensive overview of the NOAA exposure situations in the Netherlands and an indication of the levels of occupational exposure to NOAA across various life cycle of NOAA. The collected workplace exposure data and contextual information will serve as basis for future pooling of data and modelling of worker exposure.
authors.affiliation: 1.Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, the Netherlands 2.TNO, Utrechtseweg 48, 3704 HE, Zeist, the Netherlands cindy.bekker@tno.nl.
authors.forename: Cindy
authors.initials: C
authors.lastname: Bekker
authors.affiliation: 2.TNO, Utrechtseweg 48, 3704 HE, Zeist, the Netherlands.
authors.forename: Eelco
authors.initials: E
authors.lastname: Kuijpers
authors.affiliation: 2.TNO, Utrechtseweg 48, 3704 HE, Zeist, the Netherlands.
authors.forename: Derk H
authors.initials: DH
authors.lastname: Brouwer
authors.affiliation: 1.Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, the Netherlands.
authors.forename: Roel
authors.initials: R
authors.lastname: Vermeulen
authors.affiliation: 2.TNO, Utrechtseweg 48, 3704 HE, Zeist, the Netherlands.
authors.forename: Wouter
authors.initials: W
authors.lastname: Fransman
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D049329:Nanostructures; D009426:Netherlands; D016273:Occupational Exposure / Q000032:analysis*; D009790:Occupations; D010316:Particle Size; D017132:Workplace
chemical_list: D000395:Air Pollutants, Occupational
keywords: NOAA; decision logic; multi-source exposure assessment; nanomaterials; occupational exposure; personal exposure