The determination of sulphuric acid in air: A specific method

Dubois, Lena; Baker, C. Jacyn; Teichman, T.; Zdrojewski, A.; Monkman, J. L.

doi:10.1007/bf01224090

Cited by 26 publications

(5 citation statements)

References 9 publications

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“…T he occurrence of acidic droplets in the atm osphere was reported in London as early as the 1920s (W aller 1963), in Los Angeles in the 1940s (M iddleton 1950), and in O tta w a in the 1960s (Dubois et al 1969). R ecently, more intensive determ inations have be the chem ical com position of acidic fog in C alifornia (W aldm an et al 1982) where, u nder some conditions, day-tim e aerosol is converted into night-tim e fog .…”

Section: Chemical Properties Of Precipitationmentioning

confidence: 99%

Effects of acidic aerosol, fog, mist and rain on crops and trees

Jacobson

1984

Phil. Trans. R. Soc. Lond. B

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The most important factors to consider for a complete determination of the toxicity to vegetation of acidic precipitation are: settling velocity, mass transfer rates, capacity to wet surfaces; number, frequency, and duration of events; and chemical composition and concentration. Meteorological factors, such as wind velocity and humidity, also must be considered because they affect the physical, temporal, and chemical properties of precipitation. Climate is important because it influences the capacity of plants to adjust, recover, or compensate for exposure to acidic precipitation. Genotype affects the efficiency of capture and capacity to tolerate acidic conditions. Aerosol and fog droplets generally are more acidic than mist and rain but they may be less phytotoxic because smaller droplets are deposited and captured less readily by leaf surfaces except when wind velocity is high. Concentrations of acids, mainly sulphuric and nitric acids, in aerosols, fog, mist, and rain in polluted regions, appear to be insufficient to produce acute injury on vegetation except perhaps in the immediate vicinity of intense sources of emissions. Chronic effects of repeated exposure to acidic precipitation, such as the impact on plant nutrition or on processes occurring at the leaf surface-atmosphere interface, and interactions with gaseous pollutants such as ozone, cannot be evaluated at present owing to the lack of information.

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Section: Chemical Properties Of Precipitationmentioning

confidence: 99%

Effects of acidic aerosol, fog, mist and rain on crops and trees

Jacobson

1984

Phil. Trans. R. Soc. Lond. B

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“…Thermal volatilization schemes were popular for several years for speciation of acidic sulfate compounds in aerosols. Filter samples were heated and H2SO4 collected by microdiffusion (6,7) or determined directly by flame photometry after volatilization from Teflon filters (8,9). In one method, H2SO4 was distinguished from other volatile sulfates [e.g., ammonium bisulfate (NH4HSO4) and ammonium sulfate ((NH4).…”

Section: Filter Collectionmentioning

confidence: 99%

Acidic sulfate aerosols: characterization and exposure.

Lioy¹,

Waldman²

1989

Environ Health Perspect

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Exposures to acidic aerosol in the atmosphere are calculated from data reported in the scientific literature. The majority of date was not derived from studies necessarily designed to examine human exposures. Most of the studies were designed to investigate the characteristics of the atmosphere. However, the measurements were useful in defining two potential exposure situations: regional stagnation and transport conditions and local plume impacts. Levels of acidic aerosol in excess of 20 to 40 micrograms/m3 (as H2SO4) have been observed for time durations ranging from 1 to 12 hr. These were associated with high, but not necessarily the highest, atmospheric SO4(2)- levels. Exposures of 100 to 900 micrograms/m3/hr were calculated for the acid events that were monitored. In contrast, earlier London studies indicated that apparent acidity in excess of 100 micrograms/m3 (as H2SO4) was present in the atmosphere, and exposures less than 2000 micrograms/m3/hr were possible. Our present knowledge about the frequency, magnitude, and duration of acidic sulfate aerosol events and episodes is insufficient. Efforts must be made to gather more data, but these should be done in such a way that evaluation of human exposure is the focus of the research. In addition, further data are required on the mechanisms of formation of H2SO4 and on what factors can be used to predict acidic sulfate episodes.

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“…The aerosol is not significantly removed in the tube and the total sulfur in the aerosol is determined by a hydrogen-air flame photometric detector. 69 Dubois, et al 70 developed a micro-diffusion technique for the analysis of free sulfuric acid in TSP, based on the use of an ethanolic solution of sodium hydroxide to coat the inside of a glass petri dish cover and evaporated to dryness. The sample was placed in the dish, fitted with the coated cover, and heated to 195-200° C to volatilize the free acid.…”

Section: D3112-77 + S *mentioning

confidence: 99%

A Critical Review

Katz

1980

Journal of the Air Pollution Control Association

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The determination of sulphuric acid in air: A specific method

Cited by 26 publications

References 9 publications

Effects of acidic aerosol, fog, mist and rain on crops and trees

Effects of acidic aerosol, fog, mist and rain on crops and trees

Acidic sulfate aerosols: characterization and exposure.

A Critical Review

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