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Personal Exposure to Engineered Nanoparticles.

PB2013102396

Publication Date	2010
Personal Author	Peters, T. M.
Page Count	24
Abstract	Worldwide production of engineered nanoparticles is expected to grow from 2,000 metric tons to 50,000 metric tons over the next decade. New industrial processes must be introduced into the workplace to accommodate this growth. Although studies have shown some nanoparticles to be toxic, methods to assess exposure do not exist. However, knowledge of personal exposure may be particularly important for such small particles because their concentration tends to decay rapidly with distance from a source. The immediate objective of this K01 Career Development Award was to allow Dr. Thomas Peters to make a successful transition to an independent investigator in the field of occupational and environmental health, with emphasis on protecting the health of workers from exposure to aerosols. In the research component of this Award, laboratory studies were conducted under Aim 1 to develop and evaluate methods to assess personal exposure to nanoparticles. We developed a method to assess rapid fluctuations in nanoparticle concentrations with direct-read instruments and a filter-based method to quantitatively collect nanoparticles for subsequent analysis by electron microscopy. Under Aim 2 field studies, we used these methods to investigate the extent to which workers are exposed to engineered nanoparticles in facilities that produce and handle them. We found that workplace exposure to engineered nanomaterials can be highly variable by worker, by activity and/or by area of a facility. Handling nanomaterials was found to be associated with particles that were respirable but not nano-sized. Further, incidental nanoparticles were generated by hot processes and unrelated to nanomaterial handling. Samples of particles collected from workplaces were analyzed by electron microscopy with energy dispersive X-ray detection under Aim 3. These analyses allowed us to classify particles within the workplace by size, composition, and morphology. These data are critical in evaluating hazards of working with nanomaterials and controlling sources. Our field measurements have shown the inherent complexity of assessing nanoparticles in the workplace. We have identified new processes required to produce and handle engineered nanomaterials that pose a significant challenge to environmental health and safety. These processes represent a small number of many that will be required in the burgeoning field of nanotechnology. We have shown that substantial exposures to nanoparticles may occur in environments where respirable mass concentrations are low. Consequently, the industrial hygiene sampling paradigm of comparing mass measurements with mass-based OELs has severe limitations when applied to engineered nanomaterials.
Keywords	Exposure assessment Nanoparticles Occupational safety and health Aerosol particles Airborne particles Air sampling Dust Environmental health Hazards Industrial hygiene Laboratory tests Nanotechnology Particulates Work environments
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	Iowa Univ., Iowa City.; National Inst. for Occupational Safety and Health, Atlanta, GA.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Atlanta, GA.
Document Type	Technical Report
NTIS Issue Number	201305

Personal Exposure to Engineered Nanoparticles.

Personal Exposure to Engineered Nanoparticles.
PB2013102396

Publication Date	2010
Personal Author	Peters, T. M.
Page Count	24
Abstract	Worldwide production of engineered nanoparticles is expected to grow from 2,000 metric tons to 50,000 metric tons over the next decade. New industrial processes must be introduced into the workplace to accommodate this growth. Although studies have shown some nanoparticles to be toxic, methods to assess exposure do not exist. However, knowledge of personal exposure may be particularly important for such small particles because their concentration tends to decay rapidly with distance from a source. The immediate objective of this K01 Career Development Award was to allow Dr. Thomas Peters to make a successful transition to an independent investigator in the field of occupational and environmental health, with emphasis on protecting the health of workers from exposure to aerosols. In the research component of this Award, laboratory studies were conducted under Aim 1 to develop and evaluate methods to assess personal exposure to nanoparticles. We developed a method to assess rapid fluctuations in nanoparticle concentrations with direct-read instruments and a filter-based method to quantitatively collect nanoparticles for subsequent analysis by electron microscopy. Under Aim 2 field studies, we used these methods to investigate the extent to which workers are exposed to engineered nanoparticles in facilities that produce and handle them. We found that workplace exposure to engineered nanomaterials can be highly variable by worker, by activity and/or by area of a facility. Handling nanomaterials was found to be associated with particles that were respirable but not nano-sized. Further, incidental nanoparticles were generated by hot processes and unrelated to nanomaterial handling. Samples of particles collected from workplaces were analyzed by electron microscopy with energy dispersive X-ray detection under Aim 3. These analyses allowed us to classify particles within the workplace by size, composition, and morphology. These data are critical in evaluating hazards of working with nanomaterials and controlling sources. Our field measurements have shown the inherent complexity of assessing nanoparticles in the workplace. We have identified new processes required to produce and handle engineered nanomaterials that pose a significant challenge to environmental health and safety. These processes represent a small number of many that will be required in the burgeoning field of nanotechnology. We have shown that substantial exposures to nanoparticles may occur in environments where respirable mass concentrations are low. Consequently, the industrial hygiene sampling paradigm of comparing mass measurements with mass-based OELs has severe limitations when applied to engineered nanomaterials.
Keywords	Exposure assessment Nanoparticles Occupational safety and health Aerosol particles Airborne particles Air sampling Dust Environmental health Hazards Industrial hygiene Laboratory tests Nanotechnology Particulates Work environments
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	Iowa Univ., Iowa City.; National Inst. for Occupational Safety and Health, Atlanta, GA.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Atlanta, GA.
Document Type	Technical Report
NTIS Issue Number	201305