BACKGROUND Aerosol production during normal breathing is often attributed to turbulence in the respiratory tract. That mechanism is not consistent with a high degree of asymmetry between aerosol production during inhalation and exhalation. The objective was to investigate production symmetry during breathing. METHODS The aerosol size distribution in exhaled breath was examined for different b...

This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30 x 30 x 29 cm(3) nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5 to 12 standard m(3)/min. R...

We present results obtained using the new version of the multi-filter rotating shadowband radiometer (MFRSR) data analysis algorithm (Alexandrov et al. 2005). This algorithm allows the partition of aerosol optical thickness (AOT) into fine and coarse aerosol modes and to retrieve the fine mode effective radius (reff). A bimodal gamma distribution is used as the aerosol particle size model. The ...

Organosulfate species have recently gained attention for their potentially significant contribution to secondary organic aerosol (SOA); however, their temporal behavior in the ambient atmosphere has not been probed in detail. In this work, organosulfates derived from isoprene were observed in single particle mass spectra in Atlanta, GA during the 2002 Aerosol Nucleation and Characterization Exp...

A direct method was developed to determine the viability of a freshly generated mixed bacterial aerosol. A mixed suspension of (32)P-labeled Staphylococcus aureus and (35)S-labeled Proteus mirabilis was nebulized, and the aerosol was collected and separated according to particle size with an Andersen sampler. Quantitative and qualitative bacteriological and radioisotopic techniques were used to...

We undertook a new approach to investigate the aerosol indirect effect of the first kind on ice cloud formation by using available data products from the Moderate-Resolution Imaging Spectrometer (MODIS) and obtained physical understanding about the interaction between aerosols and ice clouds. Our analysis focused on the examination of the variability in the correlation between ice cloud paramet...

OBJECTIVES This paper describes a study that was carried out in the primary nickel production industry to investigate the levels of personal exposure to aerosols containing nickel and the impact on exposure assessment of introducing new personal sampling techniques with performance consistent with the latest particle size-selective criteria. METHODS Experiments were carried out at workplaces ...

We have studied the oxidation of submicron aqueous aerosols consisting of internal mixtures of sodium oleate (oleic acid proxy), sodium dodecyl sulfate, and inorganic salts by O3, NO3/N2O5, and OH. Experiments were performed using an aerosol flow tube and a continuous flow photochemical reaction chamber coupled to a chemical ionization mass spectrometer (CIMS). The CIMS was fitted with a heated...

The physical and chemical properties of an aerosol have a direct influence upon fire suppression mechanisms and extinguishing efficacy. These same properties are also basic determinants of aerosol inhalation toxicity. To evaluate the toxicity of an aerosol, it must first be determined if the aerosol can be inspired. Particles with a median aerodynamic diameter of 1-2 pm are capable ofpenetratin...

suspended aerosols in the atmosphere have strong impact on the global climate. they influence the earth’s radiation budget by scattering or absorbing both incoming and outgoing radiation. aerosols in troposphere are caused by natural sources, such as dust, sea-spray and volcanoes and also by anthropogenic sources, such as combustion of fossil fuels and biomass burning activities and from gas-to...