Atmospheric aerosols pollutants

Lundgren, D. A. Atmospheric aerosol composition and concentration as a function of particle size and of time. J. Air Pollut. Control Assoc. 20 603-608, 1970. 

Rangarajan C, Eapen CD, Gopalakrishnan SS. 1986. Measured values of the dry deposition velocities of atmospheric aerosols carrying natural and fallout radionuclides using artificial collectors. Water Air Soil Pollut 27 305-314. 

Here we have restricted our attention to atmospheric aerosols (particulate matter) because of the crucial role these particles play in adverse health effects, visibility reduction, soiling, and acid rain—the most serious effects of air pollution. However, it should be noted that many of the techniques discussed in this book also can be applied to gas-phase species. 

Atmospheric aerosols are complex mixtures of particles derived from diverse sources. Soot from diesel engines, fly ash from coal combustion, and sulfates, nitrates, and organic compounds produced by atmospheric reactions of gaseous pollutants all contribute to the aerosol. Particle size and composition depend upon the conditions of aerosol formation and growth and determine the effects of atmospheric aerosols on human health, ecosystems, materials degradation, and visibility. Much of the research on environmental aerosols has focused on fine particles ranging from a few micrometers in... 

Harrison RM, Pio CA (1983) Size-differentiated composition of inorganic atmospheric aerosols of both marine and polluted continental origin. Atmos Environ 17 1733-1738... 

Pio, C. A., Castro, L. M., and Ramos, M. O. (1993). Differentiated determination of organic and elemental carbon in atmospheric aerosol particles by a thermal-optical method. In Physico-Chemical Behaviour of Atmospheric Pollutants, Report EUR 15609/2 EN, Ange-letti, G., and Restelli, G, eds., Proceedings of the Sixth European Symposium, Vol. 2, Varese, 18-22 October, pp. 706-711. 

Several atmospheric aerosol samples were collected in Shanghai and Dalian and PCDD/Fs in total suspended particles were reported (Yang et al., 2004). The mean concentrations of total PCDD/Fs were 55.5 and 19.2 pg m-3, and the mean I-TEQs were 0.928 and 0.334pg m-3, respectively. The predominant congeners were the lower chlorinated congeners. The pollution level is comparable to the general trend of urban industrial sites (0.1-0.4 pg TEQ m-3, Lohmann and Jones, 2000). 

Vasconcelos MTSD, Taveres HMF. 1998. Atmospheric metal pollution (Cr, Cu, Fe, Mn, Ni, Pb and Zn) in Oporto City derived from results for low-volume aerosol samplers and for the moss Sphagnum auriculatum bioindicator. Sci Total Environ 212 11 -20. 

An important current problem is attaining sufficient understanding of atmospheric aerosol dynamics to develop mathematical models capable of relating emission reductions of primary gaseous and particulate pollutants to changes in ambient aerosol loadings and thereby to improvements in visibility and health effects. These models involve thermodynamics, transport phenomena, and chemical kinetics in an intricate equilibrium and... 

The on-line integration of meso-scale meteorological models and atmospheric aerosol and chemical transport models enables the utilization of all meteorological 3D fields in ACTMs at each time step and the consideration of the feedbacks of air pollution (e.g. urban aerosols) on meteorological processes and climate forcing. 

It is our estimate that all pollutant sources result in about 300 X 10 tons per year of particulate material being introduced into the atmosphere and that pollutant and natural sources combined amount to about 3000 X 10 tons per year. Thus, on a global scale 30 X 10 tons per year of pollutant photochemical aerosols are about 10% of the total pollutant aerosols and about 1% of the total annual atmospheric aerosol production. The 200 X 10 tons of aerosol particles resulting from the photochemical scavenging reactions involving natural organic emissions is somewhat less than 10% of the total aerosols emitted to the global atmosphere. 

Particle emissions resulting from natural processes should be roughly distributed according to the relative amounts of land and ocean areas in various latitudinal bands. Assuming this, natural amissions are estimated to be a function of latitude, based on the amount of land and water distributed in various latitude zones. When this is done for the northern hemisphere and compared with an estimated zonal distribution of pollutants based on Figure 3, the relative contribution of pollutant sources to atmospheric aerosol concentrations as a function of latitude is estimated. 

Figure 4. Relative contribution of pollutant aerosols to total atmospheric aerosol concentrations in the Northern Hemisphere...

Dolske D. A. and Sievering H. (1979) Trace Element loading of southern Lake Michigan by dry deposition of atmospheric aerosol. Water Air Soil Pollut. 12, 485—502. 

Because the equilibrium distribution of these substances between the wahir and the atmosphere is so much in favor of the latter—except for DDT—their removal by dissolution in rain is not very efficient (compare Section 5.5 arid Figure 5.10). Some pollutants, especially those with saturation vapor pressums lower than 10 atm (e.g., DDT and dieldrin), may be removed by adsorption to atmospheric aerosols and subsequently washed and rained out. 

---