Understanding workers' exposure: Systematic review and data-analysis of emission potential for NOAA

Area of Science:

• Occupational hygiene and exposure science
• Nanomaterial risk assessment
• Environmental health and safety

Background:

• Exposure assessment for nano-objects, aggregates, and agglomerates (NOAA) is crucial for refining conservative control banding (CB) tools.
• Existing data needs synthesis to provide a comprehensive overview of NOAA emission potential throughout occupational life cycle stages.
• Understanding emission parameters across different source domains (SD) is key for accurate risk assessment.

Purpose of the Study:

• To systematically review and analyze current knowledge on NOAA emission potential across occupational life cycle stages.
• To identify and quantify emission levels from various source domains (SD) relevant to NOAA.
• To provide data for developing and improving exposure models and risk assessment tools for nanomaterials.

Main Methods:

• Systematic literature review focusing on peer-reviewed studies of NOAA emission.
• Data normalization for workplace circumstances and measurement location to create comparable 'surrogate' emission levels.
• Descriptive statistical analysis of emission data categorized by source domain and activity.

Main Results:

• Highest emissions during nanoparticle synthesis (SD1) were from mechanical reduction and gas phase synthesis.
• For bulk nanomaterial handling (SD2), harvesting and dumping generated the highest emissions.
• Propellant gas spraying and pressure spraying showed the highest emissions in liquid processes (SD3b), while grinding led to high emissions in nano-article handling (SD4).

Conclusions:

• This study offers a valuable overview of workplace emission assessments for occupational NOAA handling.
• Emission levels derived per source domain can inform quantitative exposure prediction models.
• The findings support the refinement of control banding strategies and risk management for nanomaterials in occupational settings.