Sulfate airborne particulates

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). 

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. 

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%. 

Despite the clear evidence of a subpopulation of individuals sensitive to near-ambient peak levels of sulfur dioxide, the two-decade-old NAAQS for sulfur dioxide has not been changed nor has a short-term peak standard been instituted. A considerably greater amount of attention has been placed on the contribution of airborne particulates, particularly those associated with sulfur oxides, to adverse health effects. The carbon-, mineral-, and heavy metal-based particles produced during fossil fuel combustion and smelting promote the conversion of sulfur dioxide to sulfuric acid. Recognition of sulfur dioxide-particle interactions comes as a result of findings garnered from a number of animal studies and the characterization of sulfuric acid, ammonium sulfate, and ammonium bisulfate associated with atmospheric particles. The importance of the coexistence of sulfur oxides and particulate matter is reflected in the... 

According to a number of studies are the particles emitted from motor vehicles made up of mineral oxides, soot, numerous organic compounds, a variety of metals and metal compounds and water (Puxbaum et al. 2000). The inorganic ions sulfate, nitrate and ammonium, which were normally major constituents of airborne particulate matter, were also found in particulate vehicle emissions, but only to a minor degree since these compounds were primary formed by gas-to-particle conversion processes of gaseous precursor substances. 

Most refinery PM eomes from two sources - delayed coking units and the regenerators of fluid catalytic cracking (FCC) units. FCC regenerators also emit ammonia, which combines with SOx and NOx in the air to form ammonium sulfates and nitrates. According to the South Coast Air Quality Management District (AQMD) in Southern California, 1 ton of ammonia can generate 6 tons of PM 10 - airborne particulates with partiele diameters less than 10 microns. PM2.5 stands for airborne particulates with diameters less than 2.5 microns. 

New York was forced to take an indirect approach. While there is no air quality standard for acid sulfate, there is an air quality standard limiting the amoimt of particulate matter in the air, and acid sulfate haze is in fact a major component of airborne particulate matter in the Northeast. New York presented evidence that the Midwest s SO2 emissions contribute heavily to acid sulfate haze in the Northeast and "significantly interfere" with New York s air quality, on occasion even violating the federal limits on airborne particulates. 

The chemical composition of particulate pollutants is determined in two forms specific elements, or specific compounds or ions. Knowledge of their chemical composition is useful in determining the sources of airborne particles and in understanding the fate of particles in the atmosphere. Elemental analysis yields results in terms of the individual elements present in a sample such as a given quantity of sulfur, S. From elemental analysis techniques we do not obtain direct information about the chemical form of S in a sample such as sulfate (SO/ ) or sulfide. Two nondestructive techniques used for direct elemental analysis of particulate samples are X-ray fluorescence spectroscopy (XRF) and neutron activation analysis (NAA). 

As discussed in Chapter 7, polluted air varies in composition from locale to locale and with the time of day and meteorological conditions in a given locale. Polluted urban air contains oxides of sulfur and nitrogen, carbon monoxide, ozone, uncombusted and partially combusted hydrocarbons from gasoline and diesel vehicles, and particulate matter. PM 2.5 particulates, the standard for evaluating pollution related to cardiovascular disease, are composed of combustion products, airborne soil, sulfates, nitrates, and heavy metals as listed in Table 29.4.141-45 ... 

Zinc (and Cu) in brass and tap water were determined with the use of zincon after preliminary preconcentration on Chelex-100 column [3]. The application of V-hydroxy-AW-diphenylbenzamidine and diphenylcarbazone to the determination of zinc in airborne dust particulates has been described [4]. Trace amounts of zinc in standard alloys, environmental and pharmaceutical samples were determined by fourth derivative spectrophotometry using PAN as a reagent and ammonium tetraphenylborate supported on naphthalene as an adsorbent [5]. The detection limit was 9.5 ng ml Zn. Submicrogram amounts of zinc in water and rock samples were determined with 5-(2 -carbomethoxyphenyl)azo-8-quinolinol in the anionic micellar medium of sodium dodecyl sulfate [6]. 

The first joint shipboard and airborne smdy related to the chemical compositiOTi and water-uptake behavior of particulates in ship emissions was conducted on emissions from a Post-Panamax class container ship off the central coast of California. The results showed that the majority of particles outside the ship plume did not show slow water uptake kinetics as compared to ammonium sulfate, but in-plume particles with critical supersaturation between 0.1% and 0.35% had slower uptake kinetics than ammonium sulfate [288]. 

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