Airborne particulate matter

Environmental Aspects. Airborne particulate matter (187) and aerosol (188) samples from around the world have been found to contain a variety of organic monocarboxyhc and dicarboxyhc acids, including adipic acid. Traces of the acid found ia southern California air were related both to automobile exhaust emission (189) and, iadirecfly, to cyclohexene as a secondary aerosol precursor (via ozonolysis) (190). Dibasic acids (eg, succinic acid) have been found even ia such unlikely sources as the Murchison meteorite (191). PubHc health standards for adipic acid contamination of reservoir waters were evaluated with respect to toxicity, odor, taste, transparency, foam, and other criteria (192). BiodegradabiUty of adipic acid solutions was also evaluated with respect to BOD/theoretical oxygen demand ratio, rate, lag time, and other factors (193). 

B. W. Loo, J. M. JaMevic, and F. S. Goulding, "Dichotomous Virtual Impactors for Large Scale Monitoring of Airborne Particulate Matter," in B. Y. H. Liu, ed., Eine Particles, Aerosol Generation, Measurement, Sampling and Analysis, Academic Press, Inc., New York, 1976, pp. 311—350. 

Phthalates in Air. Atmospheric levels of phthalates in general are very low. They vary, for DEHP, from nondetectable to 132 ng/m (50). The latter value, measured in 1977, is the concentration found in an urban area adsorbed on airborne particulate matter and hence the biological avaUabUity is uncertain. More recent measurements (52) in both industrial and remote areas of Sweden showed DEHP concentrations varying from 0.3 to 77 ng/m with a median value of 2 ng/m. ... 

The monoalkyl derivatives in salt form appear to have low toxicity. The monomethyl sulfate sodium salt has an approximate oral lethal dose greater than 5000 mg/kg of body weight for rats (129). Monododecyl sulfate sodium salt is widely marketed as a detergent and shampoo ingredient (oral LD q 1268 mg/kg for rats) (126). Both dimethyl sulfate and monomethyl sulfate occur in the environment in coal fly-ash and in airborne particulate matter (130). 

Because a filter sample includes particles both larger and smaller than those retained in the human respiratory system (see Chapter 7, Section III), other types of samplers are used which allow measurement of the size ranges of particles retained in the respiratory system. Some of these are called dichotomous samplers because they allow separate measurement of the respirable and nonrespirable fractions of the total. Size-selective samplers rely on impactors, miniature cyclones, and other means. The United States has selected the size fraction below an aerodynamic diameter of 10 /xm (PMiq) for compliance with the air quality standard for airborne particulate matter. 

Airborne particulate matter, which includes dust, dirt, soot, smoke, and liquid droplets emitted into the air, is small enough to be suspended in the atmosphere. Airborne particulate matter may be a complex mixture of organic and inorganic substances. They can be characterized by their physical attributes, which influence their transport and deposition, and their chemical composition, which influences their effect on health. The physical attributes of airborne particulates include mass concentration and size distribution. Ambient levels of mass concentration are measured in micrograms per cubic meter (mg/m ) size attributes are usually measured in aerodynamic diameter. Particulate matter (PM) exceeding 2.5 microns (/i) in aerodynamic diameter is generally defined as coarse particles, while particles smaller than 2.5 mm (PMj,) are called fine particles. 

Airborne particulate matter emissions can, to a great extent, be minimized by pollution prevention and emission control measures. Prevention is frequently more cost-effective than control and, therefore, should be emphasized. Special attention should be given to pollution abatement measures in areas where taxies and buses associated with particulate emissions may pose a significant environmental risk. 

List several types of air cleaning devices that can be used to remove airborne particulate matter. Rank these in order of their collection efficiency and typical maximum size particle capture. 

Solids containing oxidized anions (carbonates, sulfates, hydroxides, and oxides) are the dominant forms of Cu in airborne particulate matter. In the few studies that have addressed the reactions of these particles in atmospheric washout, about 50% of the copper has been found to be soluble. Since the solubility is strongly dependent on pH, acid precipitation and acidification of receiving waters may have a significant effect on the form and fate of airborne copper. 

Airborne particulate matter may comprise liquid (aerosols, mists or fogs) or solids (dust, fumes). Refer to Figure 4.2. In either case dispersion, by spraying or fragmentation, will... 

Airborne particulate matter may comprise liquid (aerosols, mists or fogs) or solids (dust, fumes). Refer to Figure 5.2. Some causes of dust and aerosol formation are listed in Table 4.3. In either case dispersion, by spraying or fragmentation, will result in a considerable increase in the surface area of the chemical. This increases the reactivity, e.g. to render some chemicals pyrophoric, explosive or prone to spontaneous combustion it also increases the ease of entry into the body. The behaviour of an airborne particle depends upon its size (e.g. equivalent diameter), shape and density. The effect of particle diameter on terminal settling velocity is shown in Table 4.4. As a result ... 

Cautreels W, VanCauwenberghe K. 1978. Experiments on the distribution of organic pollutants between airborne particulate matter and the corresponding gas phase. Atmos Environ 12 1133-1141. 

Yamasaki, H., Kuwata, K., Kuge, Y. (1984) Determination of vapor pressure of polycyclic aromatic hydrocarbons in the supercooled liquid phase and their adsorption on airborne particulate matter. Nippon Kagaka Kaish. 8, 1324—1329. 

Research Priorities for Airborne Particulate Matter I. Immediate Priorities and a Long-Range Research Portfolio (1998) II. Evaluating Research Progress and Updating the Portfolio (1999)... 

Airborne particulate matter may be associated with many carcinogenic and other toxic agents. Hazardous materials include coal dust, fly-ash from power stations, metals and metal oxides from mining, extraction and refining and materials used as catalysts in industrial processes, as well as particulate matter from, for example, diesel exhausts. 

Schroeder WH, Dobson M, Kane DM, et al. 1987. Toxic trace elements associated with airborne particulate matter A review. J Air Pollut Control Assoc 37 1267-1285. 

One hint of possible trouble to come is provided by the information we described in Chapter 4, related to airborne particulate matter (PM). The available evidence ascribes significant increases in the risks of asthma and other respiratory diseases, certain cardiovascular conditions, and lung cancer to PM exposure, particularly those that average less than 2.5 pm (2500 nm) in size. As we noted, the chemical composition of these particles varies widely, depending upon source, but may not be as important as particle size as a risk determinant. Moreover, there is some experimental evidence pointing to the so-called ultra-fines, PM with dimensions below 100 nm, as significant contributors to PM risk. In addition some experimental studies have demonstrated that ultrafines not only distribute themselves throughout the airways, but seem to be able to translocate to other parts of the body - liver, heart, perhaps the CNS. 

Ciaccio, L. L., R. L. Rubino, and J. Flores. Composition of organic constituents in breathable airborne particulate matter near a highway. Environ. Sci. Technol. 8 935-942, 1974. 

Hannigan MP, Cass GR, Penman BW, Crespi CL, Busby JWF, Lafleur AL, Thilly WG, Simoneit BRT (1998) Bioassay-directed chemical analysis of Los Angeles airborne particulate matter using a human ceil mutagenicity assay. Environ Sci Technol 32 3502-3514... 

Organic compounds, natural, fossil or anthropogenic, can be used to provide a chemical mass balance for atmospheric particles and a receptor model was developed that relates source contributions to mass concentrations in airborne fine particles. The approach uses organic compound distributions in both source and ambient samples to determine source contributions to the airborne particulate matter. This method was validated for southern California and is being applied in numerous other airsheds. ... 

Schauer JJ, Rogge WF, Hildemann LM, Mazurek MA, Cass GR, Simoneit BRT, Source apportionment for airborne particulate matter using organic compounds as tfxcets, Atmos Environ 30 3837—3855, 1996. 

Physical Form. Solid often associated with or adsorbed onto ultrafine airborne particulate matter... 

Hexachlorobutadiene can exist in the atmosphere as a vapor or adsorbed to airborne particulate matter. The atmospheric burden of hexachlorobutadiene has been estimated to be 3.2 and 1.3 million kg/year for the northern and southern hemispheres, respectively (Class and Ballschmiter 1987). 

Hamers, T., Schaardenburg, M.D. van, Felzel, E.C., Murk, A.J. and Koeman, J.H. (2000).The application of reporter gene assays for the determination of the toxic potency of airborne particulate matter. Extension of Science of the... 

Based on these and other measurements of PAH levels, we suggest the following scenario for the transport of PAH. The various fuels which are burned in metropolitan areas produce airborne particulate matter (soot and fly ash) on which polycyclic aromatic hydrocarbons are adsorbed. These particles are transported by the prevailing wind for distances which are a strong function of the particle s diameter. We suggest that the long range airborne transport of small particles accounts for PAH in deep ocean sediments. 

Kleinman, M. T. The apportionment of sources of airborne particulate matter. Doctoral dissertation. New York University, New York, N.Y. (1977). 

There has been great interest in airborne particulate matter recently due to the results of a number of epidemiological studies showing a correlation between increased mortality and levels of airborne particles. Figure 2.14 shows one such correlation reported by Dockery et al. (1993). A clear relationship between mortality rates and the concentration of fine particles PM25, as well as with particle sulfate, is seen. Since sulfate is found primarily in fine particles, these observations are not independent. Schwartz et al. (1996) report a 1.5% increase in total daily mortality with an increase of 10 pg m-3 in PM25. Deaths due to chronic obstructive pulmonary disease increased by 3.3% and those to ischemic heart disease by 2.1%. 

Micallef, A., and J. J. Colls, Variation in Airborne Particulate Matter Concentration over the First Three Metres from Ground in a Street Canyon Implications for Human Exposure, Atmos. Environ., 32, 3795-3799 (1998). 

The data in Table 9.11 are based on an extensive review of the literature through 1985 by Milford and Davidson (1985). Because they represent composites of many different studies carried out in many different locations by many different investigators, they will not match any particular sample of airborne particulate matter indeed, for many of these elements, the size distribution is multimodal, which is not reflected in the median values shown in Table 9.11. On the other hand, such data demonstrate very clearly some characteristics of tropospheric particles that are common to many conditions. 

Cautreels, W., and K. Van Cauwenberghe, Experiments on the Distribution of Organic Pollutants between Airborne Particulate Matter and the Corresponding Gas Phase, Atmos. Environ., 12, 1133-1141 (1978). 

Lodge, J. P., Jr., Final Comment to Discussions of Paper Entitled Non-Health Effects of Airborne Particulate Matter, Atmos. Environ., 17, 899-909 (J983). 

Schauer, J. J., W. F. Rogge, L. M. Hildemann, M. A. Mazurek, and G. R. Cass, Source Apportionment of Airborne Particulate Matter Using Organic Compounds as Tracers, Atmos. Environ., 30, 3837-3855 (1996). 

Schroeder, W. H., M. Dobson, D. M. Kane, and N. D. Johnson, Toxic Trace Elements Associated with Airborne Particulate Matter A Review, J. Air Pollut. Control Assoc., 37, 1267-1285 (1987). 

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