Fine particle mass

Thus, consistent results are obtained about one-fourth of the fine particle mass, or 80 percent of the carbon is accounted for by vegetative-(slash) burn carbon. (The corresponding mass density of fine particles in downtown Portland from slash burning is 21 pg/m3 [33].) The only other major source of carbon is seen to be auto exhaust. 

The elderly are especially susceptible to PM effects, which are associated with fine rather than coarse particles. A recent epidemiological study found that particle number—reflecting ambient ultrafine particles—correlated better than fine particle mass with increased symptoms in asthmatics. Moreover, animal studies have shown that ultrafine particles have a significantly greater pulmonary inflammatory potency than larger submicron particles. Surface properties such as surface chemistry appear to play an important role in... 

Data on urban soil from the Portland Aerosol Study (21) were used to obtain an order of magnitude comparison of source ratios to the coefficients of MN(C) in the models. If volatile carbon (21) is assumed to be approximately equal to extractable organic matter (this study) and using a 1 1 ratio for coarse to fine particle mass in New York City (based on our unpublished data), then a ratio of extractable organic matter to MN(C) of 118 can be estimated for urban soil. The coefficients for MN(C) in the models were 46 11 [equation (16)] and 70 26 [equation (19)] for CYC and ACE, respectively. This is quite reasonable agreement in view of the approximations made to obtain a ratio for the soil source. 

St. Louis Sample Collection. Ambient aerosols were collected in St. Louis in 6-h Intervals with a TWOMASS automated sequential tape sampler. This sampler fractionated the aerosol into two size classes, fine particles having aerodynamic diameters less than 3pm, and coarse particles with diameters greater than 3pm. It was equipped with a beta-attenuation mass monitor to determine fine-particle mass (11). Only the fine particle filter was examined in this study. Pallflex E70 glass-fiber filter tape with a detachable cellulose backing (Pallflex Inc. Putnam, CT) was used with this sampler. An aerosol sampler operating from the same inlet manifold as the... 

Fine Aerosol Mass Balance. The temporal variations of fine particle mass, total carbon, elemental carbon, nitrogen, sulfur and for a typical summer period (August 4-10, 1979) and... 

Figure 3. Temporal variations of fine particle mass, total C, elemental C, N, S, and berai in St. Louis for summer 1979...

Only a few source apportionment studies report on the contribution of road dust by means of receptor models. In Athens urban area road dust might contribute up to 50% to coarse fraction and up to 20% to fine particle mass [17]. The road dust contribution of 28% to PM3 and 57% to PM10 was found in the central area of Thessaloniki while for the greater area of Thessaloniki a road dust average contribution to PM10 up to 22% was calculated [23, 37]. 

Cyrys J, Pitz M et al (2004) Relationship between indoor and outdoor levels of fine particle mass, particle number concentrations and black smoke under different ventilation conditions. J Expo Anal Environ Epidemiol 144 275-283... 

Carbonaceous materials (predominantly found in the fine size mode) and sometimes the dominant fraction of the total fine particle mass (Andrews et al., 2000 Putaud et al., 2004) have been usually classified as organic carbon (OC), elemental carbon (EC), and inorganic carbon (IC). The latter fraction typically consists of mineral carbonates derived almost exclusively from soil dust (Seinfeld and Pankow, 2003). Since mineral carbonates are commonly discarded from chemical aerosol mass closures, data on total carbon (TC) content of air particulate matter at sites representing different pollution levels refers only to the sum of OC and EC... 

Visual range is inversely related to the atmospheric scattering coefficient, which is proportional to the fine-particle mass concentration. The two most important constituents in urban areas are elemental carbon and sulfates. 

As fine particles arise from many sources, it would be desirable to replace the fine particle mass concentration in the equations by the concentration of an element borne by the fine particles from coal combustion and no other source. The best candidate for such an element is Se (2.4.17). If coal-fired power plants were the only significant source of Se (probably a good assumption in many areas), one could measure emission rates of SO2, SO4 and Se from the source and their concentrations at a downwind location and plug the values into the equations and solve them to obtain the conversion and deposition rates averaged over the travel time of the plume. The model is a useful first step towards the use of... 

Seale, J. P., and Harrison, L. I. (1998), Effect of changing the fine particle mass of inhaled beclomethasone dipropionate on intrapulmonary deposition and pharmacokinetics, Respir. Med., 92(Suppl. A), 9-15. 

Coarse plus fine particle mass concentration... 

Blacker, R. Morton, R.W. Mitchell, J.P. Nagel, M.W. Hess, D.R. The Effect of Small Volume Nebulizer (SVN) Design on Fine Particle Mass Delivery of a Bronchodilator, Present at Drug Delivery to the Lungs, London, UK, Dec., 1999. 

If the product under development is transitioning from an existing CFC suspension-based product, it may be difficult to replicate the fine particle mass, the particle size distribution and/or the absorption characteristics. This can lead to problems in providing a seamless transition from the CFC product because of the potential to have to change the dose and because the product can smell and feel different to the original suspension formulation. 

Table VI summarizes aerosol mass concentrations and composition in different regions of the troposphere. It is interesting to note that average total fine particle mass (that associated with particles of diameter less than about 2 /im) in non-urban continental, i.e., regional, aerosols is only a factor of two lower than urban values. This reflects the relatively long residence time of particles (recall the estimate of a lifetime of fine particles by dry deposition of 10 days). Correspondingly, the average composition of non-urban continental and urban aerosols is roughly the same. The average mass concentration of remote aerosols is a factor of three lower than that of non-urban continental aerosols. The elemental carbon component, a direct indicator of anthropogenic combustion sources, drops to 0.3% in the remote aerosols, but sulfate is still a major compo-...

Particle/Droplet Size and Fine Particle Mass.337... 

Particle size distribution is a multivariate parameter. In early development it is often described by a single point control known as fine particle mass, typically being the mass of particles less than or equal to 5 /rm. As development proceeds, more complex specifications are developed whereby the particle size distribution is represented by a number of particle size fractions between 1 and 10 /rm, with requirements linked to batches used clinically. 

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