Outdoor smog chamber studies:  light effects relative to indoor chambers

Jeffries, Harvey E.; Fox, Donald L.; Kamens, Richard M.

doi:10.1021/es60121a016

Cited by 41 publications

(27 citation statements)

References 12 publications

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“…Environmental irradiation chambers (also called smog chambers) that use sunlight can be used to study systems of natural transformation chemistry of pollutants (Jeffries et al 1976; Jeffries and Fowler 2000; Sexton et al 2004). Dual 150,000-L University of North Carolina (UNC) outdoor smog chambers made of FEP Teflon film (Livingstone Coating Corporation, Charlotte, NC) were used as photochemical reactors during the experiments.…”

Section: Methodsmentioning

confidence: 99%

“…The chambers are located in Chatham County, North Carolina. Descriptive information about the chambers has been previously published (Jeffries et al 1976; Jeffries and Fowler 2000). These chambers are ideal for studying chemical systems that are part of the real photochemical phenomena that occur within the atmosphere because the FEP Teflon film allows ultraviolet and visible regions of sunlight to react with the chemical components in the chamber.…”

Section: Methodsmentioning

confidence: 99%

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Effects of 1,3-Butadiene, Isoprene, and Their Photochemical Degradation Products on Human Lung Cells

Doyle¹,

Sexton²,

Jeffries³

et al. 2004

Environ Health Perspect

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Because of potential exposure both in the workplace and from ambient air, the known carcinogen 1,3-butadiene (BD) is considered a priority hazardous air pollutant. BD and its 2-methyl analog, isoprene (ISO), are chemically similar but have very different toxicities, with ISO showing no significant carcinogenesis. Once released into the atmosphere, reactions with species induced by sunlight and nitrogen oxides convert BD and ISO into several photochemical reaction products. In this study, we determined the relative toxicity and inflammatory gene expression induced by exposure of A549 cells to BD, ISO, and their photochemical degradation products in the presence of nitric oxide. Gas chromatography and mass spectrometry analyses indicate the initial and major photochemical products produced during these experiments for BD are acrolein, acetaldehyde, and formaldehyde, and products for ISO are methacrolein, methyl vinyl ketone, and formaldehyde; both formed < 200 ppb of ozone. After exposure the cells were examined for cytotoxicity and interleukin-8 (IL-8) gene expression, as a marker for inflammation. These results indicate that although BD and ISO alone caused similar cytotoxicity and IL-8 responses compared with the air control, their photochemical products significantly enhanced cytotoxicity and IL-8 gene expression. This suggests that once ISO and BD are released into the environment, reactions occurring in the atmosphere transform these hydrocarbons into products that induce potentially greater adverse health effects than the emitted hydrocarbons by themselves. In addition, the data suggest that based on the carbon concentration or per carbon basis, biogenic ISO transforms into products with proinflammatory potential similar to that of BD products.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Effects of 1,3-Butadiene, Isoprene, and Their Photochemical Degradation Products on Human Lung Cells

Doyle¹,

Sexton²,

Jeffries³

et al. 2004

Environ Health Perspect

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“…The following two reactions both variable and much more rapid than their homogeneous rates, the rate constants of these reactions have sometimes been used as adjustable parameters in order to account for the high radical production rates observed in smog chambers [15,23]. The homogeneous rate constants for these reactions are probably too low for them to occur at significant rates in the SAPRC evacuable chamber (see note 52 of the Appendix Figure 9.…”

Section: Unknown Radical Sources In Chamber Runsmentioning

confidence: 99%

Computer modeling of smog chamber data: Progress in validation of a detailed mechanism for the photooxidation of propene and n‐butane in photochemical smog

Carter

Lloyd

Sprung

et al. 1979

Int J of Chemical Kinetics

162

153

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A detailed mechanism is presented far reactions occurring during irradiation of part-permillion concentrations of propene and/or n-butane and oxides of nitrogen in air. Data from an extensive series of well-characterized smog chamber experiments carried out in our 5800-liter evacuable chamber-solar simulator facility designed for providing data suitable for quantitative model validation were used to elucidate several unknown or uncertain kinetic parameters and details of the reaction mechanism.The mechanism was then tested against the data base from the smog chamber runs. In general, most calculated concentration-time profiles agreed with experiments to within the experimental uncertainties. Fits were usually attained to within f20% or better for ozone, NO, propene, and n-butane, to within -+30% or better for NOz, PAN, methyl ethyl ketone, 2-butyl nitrate, butyraldehyde, and (in runs not containing propene) methyl nitrate, to within --f50% or better for the minor products 1-butyl nitrate and propene oxide, and to within a factor of 2 for methyl nitrate in propene-containing runs. Propionaldehyde was consistently underpredicted in all runs; it is probably a chamber contaminant. For formaldehyde and acetaldehyde, the major products in both systems, fits to within -420% were often obtained, yet for a number of experiments, significantly greater discrepancies were observed, probably as a result of experimental and/or analytical problems.The good fits to experimental data were attained only after adjusting several rate constants or rate constant ratios related to uncertainties concerning chamber effects or the chemical mechanism. The largest uncertainty concerns the necessity to include in the mechanism a significant rate of radical input from unknown sources in the smog chamber. Other areas where fundamental kinetic and mechanistic data are most needed before a predictive, detailed propene + n-butane-NO,-air smog model can be completely validated concern other chamber effects, the 03 + propene mechanism, decomposition rates of substituted alkoxy radicals, CARTER E T AL.primary quantum yields for radical production as a function of wavelength for aldehyde and ketone photolyses, and the mechanisms and rates of reactions of peroxy radicals with NO and NOz.

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“…Environmental parameters including temperature, relative humidity, and light intensity were also monitored to compute chemical and photochemical reaction rates. Detailed descriptions of the chamber and measurement instruments employed can be found elsewhere (Jeffries et al, 1976). Sixteen characterization runs were chosen to evaluate the light model and wall chemistry parameters represented in the auxiliary mechanism.…”

Section: Methodsmentioning

confidence: 99%

Assessment of SAPRC07 with updated isoprene chemistry against outdoor chamber experiments

Chen

Sexton

Jerry

et al. 2015

Atmospheric Environment

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a b s t r a c tIsoprene, the most emitted non-methane hydrocarbon, is known to influence ozone (O 3 ) formation in urban areas rich with biogenic emissions. To keep up with the recent advance on isoprene oxidation chemistry including the identification of isoprene epoxydiols (IEPOX) as a precursor to secondary organic aerosol (SOA), Xie et al. (2013) updated the SAPRC (Statewide Air Pollution Research Center)-07 chemical mechanism. It is currently unknown how the Xie modification of SAPRC07 impacts the ability of the model to predict O 3 . In this study we will evaluate the Xie mechanism with simulations of 24 isoprene experiments from the UNC Dual Gas-phase Chamber. Our results suggest that the new mechanism increases NO x (nitrogen oxides) inter-conversion and produces more O 3 than SAPRC07 for all experiments. In lower-NO x experiments, the new mechanism worsens O 3 performance in the wrong direction, increasing bias from 4.92% to 9.44%. We found increased NO x recycling from PANs accounts for that. This could be explained by more PANs made due to increased first generation volatile organic compound (VOC) products and hydroxyl radical (OH) production.

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Outdoor smog chamber studies: light effects relative to indoor chambers

Cited by 41 publications

References 12 publications

Effects of 1,3-Butadiene, Isoprene, and Their Photochemical Degradation Products on Human Lung Cells

Effects of 1,3-Butadiene, Isoprene, and Their Photochemical Degradation Products on Human Lung Cells

Computer modeling of smog chamber data: Progress in validation of a detailed mechanism for the photooxidation of propene and n‐butane in photochemical smog

Assessment of SAPRC07 with updated isoprene chemistry against outdoor chamber experiments

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