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Exposing the Exposures : Assessing occupational aerosol exposures and their possible health and toxicological effects

Lovén, Karin LU (2020)
Abstract
According to the Global Burden of Disease study, occupational exposures to particulates, gases and fumes were responsible for 0.36 million deaths and 8.8 million disability-adjusted life years globally in 2015. This thesis focuses on two occupational groups that are at risk for developing adverse health effects from the time they spend in their working environments: cleaning workers and workers in the nanotechnology industry. For both of these occupational groups, who are affected by the introduction of new products into their occupational environments, knowledge is needed about the present exposure situations, as well as evaluations of the potential health and toxicological effects of these exposures.

The overall aim of the... (More)
According to the Global Burden of Disease study, occupational exposures to particulates, gases and fumes were responsible for 0.36 million deaths and 8.8 million disability-adjusted life years globally in 2015. This thesis focuses on two occupational groups that are at risk for developing adverse health effects from the time they spend in their working environments: cleaning workers and workers in the nanotechnology industry. For both of these occupational groups, who are affected by the introduction of new products into their occupational environments, knowledge is needed about the present exposure situations, as well as evaluations of the potential health and toxicological effects of these exposures.

The overall aim of the research presented in this thesis was to provide a basis for the implementation of improvements of the working environments for these two occupational groups by addressing the research needs within them. Aerosol emissions and exposures present in the two occupational settings were characterized, and the potential health and toxicological effects that can possibly arise from these types of exposures were evaluated. Extensive methodological approaches were used, divided into the three overall categories of contextual information gathering, aerosol characterization, and health/toxicity assessment.

To assess the working environment of cleaning workers, with a specific focus on the possible aerosol exposure generated during spray use, an initial phone inquiry of cleaning companies (n = 20) with a following survey among professional cleaning workers (n = 225) were conducted. Characterizations of the spray aerosol were performed with both off-line and on-line methods. A human chamber exposure study was then conducted to evaluate acute health effects due to the use of different cleaning methods.

To assess the working environment in the nanotechnology industry, three different companies were studied. Contextual information was collected from the companies about the type of materials and processes they were handling. Workplace measurements were then conducted to characterize the current engineered nanomaterial (ENM) emission and exposure situations. Relevant toxicological assessments are also needed to evaluate the potential ENMs’ hazards. A comparative study of the toxicity of a common ENM assessed with different cell exposure systems was therefore carried out. The more advanced Nano Aerosol Chamber for In Vitro Toxicity (NACIVT) system was compared with two traditionally submerged toxicological exposure systems to understand the similarities and differences between them.

Worker’s exposures could be determined within both occupations. We showed that the use of cleaning sprays results in an aerosol exposure, but with a large variety between different products. Between 2.7 and 32.2% of the liquid leaving the bottle during spraying remained airborne and could constitute potential airway exposure. We also showed that the nose was the part of the respiratory system most affected by spray use, but that switching to a foaming application method greatly reduced both the aerosol concentration and the observed negative health effects.

At the nanotechnology companies, emissions and exposures were found from all three fibrous nanomaterials that were handled, foremost during the manual cleaning of the ENM production reactor and during the handling of both dry ENM powder and ENM-containing liquid. Comparing the different toxicological exposure systems revealed a higher sensitivity in the NACIVT system than the two traditionally submerged systems. This result encourages the use of more physiologically realistic cell exposure systems.

The knowledge generated by the thesis research can be used to promote safe working environments. Exposure data together with hazard/toxicity information can be used to provide improved risk assessments. The comparison and evaluation of measurement techniques can be used in recommendations to occupational hygienists. The identification of processes that cause exposure events can be used by companies to implement suitable mitigation systems. All this can be done to achieve healthier workplace conditions! (Less)
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author
supervisor
opponent
  • Dr. Viana Rodriguez, Mar, CSIC, Spain.
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Aerosol, Occupational exposure, Spray, Engineered nanomaterial, Air-liquid interface, Toxicology
issue
67
pages
73 pages
publisher
Division of Ergonomics and Aerosol Technology, Department of Design Sciences Lund University
defense location
Lecture hall Stora hörsalen, IKDC, Sölvegatan 26, Faculty of Engineering LTH, Lund University, Lund. Follow online: https://youtu.be/dahlzfOYFtg
defense date
2020-05-15 10:15:00
ISSN
1650-9773
ISBN
978-91-7895-472-8
978-91-7895-473-5
language
English
LU publication?
yes
id
cd742172-313b-4600-b4e6-490033e14ca9
date added to LUP
2020-04-17 16:40:25
date last changed
2021-03-10 10:20:51
@phdthesis{cd742172-313b-4600-b4e6-490033e14ca9,
  abstract     = {According to the Global Burden of Disease study, occupational exposures to particulates, gases and fumes were responsible for 0.36 million deaths and 8.8 million disability-adjusted life years globally in 2015. This thesis focuses on two occupational groups that are at risk for developing adverse health effects from the time they spend in their working environments: cleaning workers and workers in the nanotechnology industry. For both of these occupational groups, who are affected by the introduction of new products into their occupational environments, knowledge is needed about the present exposure situations, as well as evaluations of the potential health and toxicological effects of these exposures.<br/><br/>The overall aim of the research presented in this thesis was to provide a basis for the implementation of improvements of the working environments for these two occupational groups by addressing the research needs within them. Aerosol emissions and exposures present in the two occupational settings were characterized, and the potential health and toxicological effects that can possibly arise from these types of exposures were evaluated. Extensive methodological approaches were used, divided into the three overall categories of contextual information gathering, aerosol characterization, and health/toxicity assessment.<br/><br/>To assess the working environment of cleaning workers, with a specific focus on the possible aerosol exposure generated during spray use, an initial phone inquiry of cleaning companies (n = 20) with a following survey among professional cleaning workers (n = 225) were conducted. Characterizations of the spray aerosol were performed with both off-line and on-line methods. A human chamber exposure study was then conducted to evaluate acute health effects due to the use of different cleaning methods.<br/><br/>To assess the working environment in the nanotechnology industry, three different companies were studied. Contextual information was collected from the companies about the type of materials and processes they were handling. Workplace measurements were then conducted to characterize the current engineered nanomaterial (ENM) emission and exposure situations. Relevant toxicological assessments are also needed to evaluate the potential ENMs’ hazards. A comparative study of the toxicity of a common ENM assessed with different cell exposure systems was therefore carried out. The more advanced Nano Aerosol Chamber for In Vitro Toxicity (NACIVT) system was compared with two traditionally submerged toxicological exposure systems to understand the similarities and differences between them.<br/><br/>Worker’s exposures could be determined within both occupations. We showed that the use of cleaning sprays results in an aerosol exposure, but with a large variety between different products. Between 2.7 and 32.2% of the liquid leaving the bottle during spraying remained airborne and could constitute potential airway exposure. We also showed that the nose was the part of the respiratory system most affected by spray use, but that switching to a foaming application method greatly reduced both the aerosol concentration and the observed negative health effects.<br/><br/>At the nanotechnology companies, emissions and exposures were found from all three fibrous nanomaterials that were handled, foremost during the manual cleaning of the ENM production reactor and during the handling of both dry ENM powder and ENM-containing liquid. Comparing the different toxicological exposure systems revealed a higher sensitivity in the NACIVT system than the two traditionally submerged systems. This result encourages the use of more physiologically realistic cell exposure systems.<br/><br/>The knowledge generated by the thesis research can be used to promote safe working environments. Exposure data together with hazard/toxicity information can be used to provide improved risk assessments. The comparison and evaluation of measurement techniques can be used in recommendations to occupational hygienists. The identification of processes that cause exposure events can be used by companies to implement suitable mitigation systems. All this can be done to achieve healthier workplace conditions!},
  author       = {Lovén, Karin},
  isbn         = {978-91-7895-472-8},
  issn         = {1650-9773},
  language     = {eng},
  month        = {04},
  number       = {67},
  publisher    = {Division of Ergonomics and Aerosol Technology, Department of Design Sciences Lund University},
  school       = {Lund University},
  title        = {Exposing the Exposures : Assessing occupational aerosol exposures and their possible health and toxicological effects},
  url          = {https://lup.lub.lu.se/search/ws/files/78487949/Karin_Lov_n_Thesis_web.pdf},
  year         = {2020},
}