The measured concentrations have no toxicological effect when inhaled.Three types of face masks were tested under different conditions.Concentration of CO 2 in the breathing zone while wearing a face mask was determined.Effect of Wearing Face Masks on the Carbon Dioxide Concentration in the Breathing Zone. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited. Results of this project, coordinated with deposition modeling and bioavailability studies will be useful in the development of a model to characterize lead dose to workers based on known parameters within the work specifications.European Commission, Joint Research Centre (JRC), Ispra, ItalyĬopyright The Author’s institutions. Mass concentrations of lead in air samples varied directly with lead concentration in the bulk coating. The distribution of lead did not appear to be affected by grit size of the abrasive in that the lead distribution within the particle size ranges remained homogeneous and consistent with the lead concentration in the dried film. Particulate mass concentrations of dust varied directly with abrasive grit number. inversely related to the abrasive grit number). Findings of the research indicated that the particle size distribution in the dust is directly related to the grit size of the abrasive (i.e. Correlation coefficients (Pearson's r) were used to determine the relationship between factors. Student's t-tests were used to evaluate changes in MMADs, mass concentrations and other indices for inter and intra-grit size samples. Mass concentrations were evaluated using a MIE Mass Concentration Analyzer and gravimetric analysis of filter samples collected in the breathing zone. Lead distribution was determined using the five stage cyclone, and personal or area samples analyzed using inductively coupled plasma (ICP). Particle size distributions were evaluated using a TSI Aerodynamic Particle Sizer, a five stage cyclone and scanning electron microscopy. The Mass Median Aerodynamic Diameter (MMAD) was used as an indicator of change in the particle size distribution. It also examined the distribution of lead within selected particle sizes. The study examined the relationship between particle size in the dust and grit size of the abrasive. This study attempts to clarify the mechanisms involved in the generation and transportation of the dust to the worker by evaluating the relationship of a number of key factors on particle size and lead distribution within the aerosol dust generated when lead based paint is removed by sanding. Both phases involve complex interactions and there are a number of factors within each phase that significantly affect the potential lead dose for the worker. The process from dried film to aerosol (airborne dust) exposure, and on to dose can be separated into two major phases (1) generation of the dust and its transport through the air to the worker and (2) uptake and dose related factors within the body. Simultaneous sampling procedures from the same paint removal operation may differ by several orders of magnitude. Intuitively a direct relationship must exist but confounding factors confuse the issue. The relationship between lead concentration in the dry film of lead based paints applied to steel bulkheads aboard ship, the lead concentration found in the air when the paint is removed by mechanical means, and blood lead concentrations of workers involved in lead based paint removal has not been well characterized.

Breathing zone concentration