Secondary particulate

Nitrogen oxides (NO ) are formed during the combustion at high temperature of fossil fuels and of biomasses and are blamed for the production of acid rain, the formation of ozone in the troposphere and of secondary particulate matter and for causing a reduction in breathing functionality and damage to the cardio-circulatory system in humans. 

Secondary particulates were found to account for about 8% and automotive exhaust about 10% of the annual average mass. 

In developing a multiple regression model for apportioning sources of TSP in New York City, Kleinman, et al.(2) selected Pb, Mn, Cu, V and SO, as tracers for automotive sources, soil-related sources, incineration, oil-burning and secondary particulate matter, respectively. These were chosen on the basis of the results of factor analysis and a qualitative knowledge of the principal types of sources in New York City and the trace metals present in emissions from these types of sources. Secondary TSP, automotive sources and soil resuspension were found to be the principal sources of TSP in 1974 and 1975 ( ). 

Fine PM, Sioutas C, Solomon PA (2008) Secondary particulate matter in the United States insights from the particulate matter supersites program and related studies. J Air Waste Manage Assoc 58(2) 234—253... 

Metrics such as DALYs are derived from statistics for mortality. These are dominant for cancer effects. Equivalent numbers of DALYs, calculated using social science techniques, are provided for the years of life lost for morbidity (nonfatal) effects. Further developments remain necessary for noncancer toxicological effects. Although some DALY-based characterization factors are available from epidemiological data for respiratory illness, including for secondary particulate matter (nitrates and sulfates). 

The vast majority of dollar-valued benefits from air pollution abatement arise from the impact of airborne particulates (PM2 5) on premature mortality. A 1997 EPA study reports that of the estimated 22.2 trillion worth of benefits derived from the Clean Air Act of 1970, reductions in particulate-related mortality contributed more than 20 trillion. We use a spatially-detailed air pollution dispersion model (the Source-Receptor Matrix) to evaluate the impact of SO2 emission reductions from each plant on county-level concentrations of particulates during Phase I of Title IV. Using existing evidence on the connection between particulate exposures and mortality, we translate the reductions in secondary particulate concentrations in each county in the United States into the dollar benefits from reductions in premature mortality. 

Our measure of HEALTH CHG concentrates on the long-term mortality effects of particulate matter (PM25)—an assumption consistent with past studies (Rowe et al. 1995 Levy et al. 1999). Since our study focuses on the benefits of reduced SOj emissions we concentrate on the health benefits from lower concentrations of secondary particulates that result from SO2 emissions. We use the findings from the American Cancer Society study, the most comprehensive analysis of long-term mortality effects from air pollu-... 

Emissions from motor vehicles are among the major contributors to fine particle concentrations in the urban atmosphere (Schauer et al. 1996 Kleeman et al. 2000) they make substantial direct and indirect contributions to ambient PM levels. Direct particulate emission sources from vehicles include their exhaust (Mulawa et al. 1997 Sagebiel et al. 1997), the mechanical wear of tires and brakes (Rogge et al. 1993 Garg et al. 2000), and the ejection of particles from the pavement (Kupiainen et al. 2005) and unpaved road shoulders (Moosmiiller et al. 1998) as well as re-suspension processes (Nicholson et al. 1989 Stembeck et al. 2002). Indirect contributions include the emission of reactive gases, both organic and inorganic, which form secondary particulate matter via atmospheric transformations. 

The scope of this section has been limited to an introduction to the most widespread anthropogenic particle emission sources. There are multiple additional sources of primary and secondary particulate sources, including, but not limited to waste incineration, construction, agricultural processes, cigarette smoke and fugitive emissions. 

The corrosion resistance of 3xxx wrought aluminum alloys is very high. The manganese is present in the aluminum matrix as submicroscopic precipitates. The secondary particulate phases are intermetallic compound particles such as MnAl. Good resistance to corrosion of these series is primarily explained electrochemically - the corrosion potential of MnAl is almost the same as that of the aluminum matrix. 

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