Aerosol sampling bias from differential electrostatic charge and particle size
Lack of reliable epidemiological data on long term health effects of aerosols is due in part to inadequacy of sampling procedures and the attendant doubt regarding the validity of the concentrations measured. Differential particle size has been widely accepted and studied as a major potential biasing effect in the sampling of such aerosols. However, relatively little has been done to study the effect of electrostatic particle charge on aerosol sampling. The objective of this research was to investigate the possible biasing effects of differential electrostatic charge, particle size and their interaction on the sampling accuracy of standard aerosol measuring methodologies. Field studies were first conducted to determine the levels and variability of aerosol particle size and charge at two manufacturing facilities making acrylic powder. The field work showed that the particle mass median aerodynamic diameter (MMAD) varied by almost an order of magnitude (4-34 microns) while the aerosol surface charge was relatively stable (0.6-0.9 micro coulombs/m/sup 2/). The second part of this work was a series of laboratory experiments in which aerosol charge and MMAD were manipulated in a 2/sup n/ factorial design with the percentage of sampling bias for various standard methodologies as the dependent variable. The experiments used the same friable acrylic powder studied in the field work plus two size populations of ground quartz as a nonfriable control. Despite some ill conditioning of the independent variables due to experimental difficulties, statistical analysis has shown aerosol charge (at levels comparable to those measured in workroom air) is capable of having a significant biasing effect.
- Research Organization:
- Drexel Univ., Philadelphia, PA (USA)
- OSTI ID:
- 6918120
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AEROSOLS
ELECTRIC CHARGES
ELECTROSTATICS
SAMPLING
AIR SAMPLERS
PERFORMANCE
CHEMICAL PLANTS
AEROSOL MONITORING
AIR
AIR POLLUTION
EXPERIMENTAL DATA
PARTICLE SIZE
PARTICLES
POLYACRYLATES
POWDERS
QUARTZ
AIR POLLUTION MONITORING
CHALCOGENIDES
COLLOIDS
DATA
DISPERSIONS
EQUIPMENT
ESTERS
FLUIDS
GASES
INDUSTRIAL PLANTS
INFORMATION
MINERALS
MONITORING
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
POLLUTION
POLYMERS
POLYVINYLS
SAMPLERS
SILICON COMPOUNDS
SILICON OXIDES
SIZE
SOLS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)