Observations and modeling of formaldehyde at the PROPHET mixed hardwood forest site in 2008

Galloway, Melissa M.; DiGangi, J. P.; Hottle, J.; Huisman, Andrew J.; Mielke, L. H.; Alaghmand, M.; Shepson, P. B.; Weremijewicz, Joanna; Klavon, Hugh; McNeal, Fredrick M.; Carroll, Mary Anne; Griffith, Stephen M.; Hansen, R. F.; Dusanter, Sébastien; Stevens, P. S.; Bertman, S. B.; Keutsch, Frank N.

doi:10.1016/j.atmosenv.2011.09.053

Cited by 9 publications

(13 citation statements)

References 39 publications

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“…R GF does not change significantly during the fast increases and decreases of Gly and HCHO concentrations, which is consistent with the similarity of the Gly and HCHO dependence on NO during MBO and isoprene oxidation used in common chemical mechanisms (e.g. University of Leeds Master Chemical Mechanism) (Galloway et al, 2012). The available NO data, although limited in quantity and sensitivity, generally agrees with this hypothesis (campaign midday median: ∼ 100 pptv).…”

Section: Anthropogenic Influence On Bvoc Oxidation Via Nosupporting

confidence: 84%

“…Most models predict lower yields of Gly and HCHO with decreasing NO (i.e. RO 2 + HO 2 becomes increasingly dominant) (Galloway et al, 2012). The morning decreases of Gly and HCHO observed during BEACHON-ROCS are consistent with a transition from a higher NO regime to a lower NO regime, and the afternoon/evening increases are the opposite.…”

Section: Anthropogenic Influence On Bvoc Oxidation Via Nomentioning

confidence: 83%

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Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry

DiGangi¹,

Henry²,

Kammrath³

et al. 2012

Preprint

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We present simultaneous fast, in-situ measurements of formaldehyde and glyoxal from two rural campaigns, BEARPEX 2009 and BEACHON-ROCS, both located in Pinus Ponderosa forests with emissions dominated by biogenic volatile organic compounds (VOCs). Despite considerable variability in the formaldehyde and glyoxal concentrations, the ratio of glyoxal to formaldehyde, RGF, displayed a very regular diurnal cycle over nearly 2 weeks of measurements. The only deviations in RGF were toward higher values and were the result of a biomass burning event during BEARPEX 2009 and very fresh anthropogenic influence during BEACHON-ROCS. Other rapid changes in glyoxal and formaldehyde concentrations have hardly any affect on RGF and could reflect transitions between low and high NO regimes. The trend of increased RGF from both anthropogenic reactive VOC mixtures and biomass burning compared to biogenic reactive VOC mixtures is robust due to the short timescales over which the observed changes in RGF occurred. Satellite retrievals, which suggest higher RGF for biogenic areas, are in contrast to our observed trends. It remains important to address this discrepancy, especially in view of the importance of satellite retrievals and in-situ measurements for model comparison. In addition, we propose that RGF, together with the absolute concentrations of glyoxal and formaldehyde, represents a useful metric for biogenic or anthropogenic reactive VOC mixtures. In particular, RGF yields information about not simply the VOCs in an airmass, but the VOC processing that directly couples ozone and secondary organic aerosol production

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Section: Anthropogenic Influence On Bvoc Oxidation Via Nosupporting

confidence: 84%

Section: Anthropogenic Influence On Bvoc Oxidation Via Nomentioning

confidence: 83%

Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry

DiGangi¹,

Henry²,

Kammrath³

et al. 2012

Preprint

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“…The rate of CH 2 O production can be related to the rate of OH loss by incorporating the fractional yield of CH 2 O ( α Xi ) from each reaction that consumes OH (P CH2O = Σ α Xi k Xi+OH [X i ] [OH]). Instead of treating each species and its yield separately [e.g., α CH4 ≤ 1, α CO,NO2 = 0; e.g., Sumner et al ., ; Galloway et al ., ], we define an effective yield ( α eff : P CH2O P OH −1 ). Thus, the rate of CH 2 O production equals the rate of OH production (P OH ) multiplied by the effective yield of CH 2 O ( α eff : P CH2O P OH −1 ).…”

Section: A Steady State Model For the Ch2o Column: F(pohvoc Reactivity)mentioning

confidence: 99%

“…The measurements of the CH 2 O column have primarily been used to investigate the emissions of isoprene (E ISOP ) and other short-lived VOC that give rise to large, localized enhancements of CH 2 O [e.g., Palmer et al, 2003Palmer et al, , 2006Fu et al, 2007;Barkley et al, 2008Barkley et al, , 2013Millet et al, 2008;Stavrakou et al, 2009aStavrakou et al, , 2009bCurci et al, 2010;Marais et al, 2012Marais et al, , 2014Zhu et al, 2014]. It is well known, however, that the concentration of CH 2 O also depends on the concentration of OH, both in isoprene-rich regions [e.g., Sumner et al, 2001;Butler et al, 2008;Galloway et al, 2012] and in regions where CH 4 is the dominant VOC [e.g., Song et al, 2010]. We thus hypothesize that variability in the CH 2 O column systematically reflects variations of the OH radical, in addition to reflecting variations of VOC.…”

Section: Introductionmentioning

confidence: 99%

The role of OH production in interpreting the variability of CH₂O columns in the southeast U.S.

et al. 2016

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Formaldehyde (CH2O), a key atmospheric oxidation intermediate that is detectable from satellite‐based UV/visible spectrometers, is primarily formed when hydroxyl radical (OH) reacts with volatile organic compounds (VOC) and is removed by photolysis, reaction with OH or deposition. We investigate the influence of OH and VOC variability on the CH2O column using a steady state model and the WRF‐Chem regional chemical transport model over the southeast United States for the summer of 2012 (June–August). The steady state model indicates that the CH2O column primarily depends on OH production rates (POH) at low concentrations of OH (<3 × 106 molecules cm−3), on both POH and VOC reactivity (VOCR: Σiki[VOC]i) at moderate concentrations of OH (3 × 106–7 × 106 molecules cm−3) and on VOCR at high concentrations of OH (>7 × 106 molecules cm−3). When constrained with WRF‐Chem values of boundary layer average POH and VOCR, the steady state model of CH2O explains most of the daily (r2 = 0.93) and average June–August (r2 = 0.97) spatial variance of the fully simulated cloud‐free CH2O column. These findings imply that measurements of the CH2O column offer the potential to better understand the processes affecting oxidation, particularly in remote regions, where OH concentrations are low. The findings also suggest that the inference of VOC emissions based on measurements of CH2O, or any other intermediate oxidation species with a photolytic lifetime that is short relative to removal by reaction with OH (e.g., glyoxal), should carefully account for the influence of OH on the observed pattern, especially where OH concentrations are below 5 × 106 molecules cm−3, as occurs in remote forests, where OH strongly varies, as occurs downwind of large nitrogen oxide (NOx: NO+NO2) emission sources, or where OH sources are potentially biased.

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“…Low rural FA concentrations have been confirmed in a study from the northern Michigan. FA concentrations varied from 0.5 ppb (0.6 μg/m 3 ; night maximum) to about 4 ppb (5 μg/m 3 ; daytime maximum) in a mixed hardwood forest at days with a wind direction from areas with low anthropogenic pollution; FA was mainly due to oxidation of isoprene (Galloway et al 2012). …”

Section: Exposuresmentioning

confidence: 99%

Recent trend in risk assessment of formaldehyde exposures from indoor air

2012

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Studies about formaldehyde (FA) published since the guideline of 0.1 mg/m3 by the World Health Organization (WHO) in 2010 have been evaluated; critical effects were eye and nasal (portal-of-entry) irritation. Also, it was considered to prevent long-term effects, including all types of cancer. The majority of the recent toxicokinetic studies showed no exposure-dependent FA–DNA adducts outside the portal-of-entry area and FA–DNA adducts at distant sites were due to endogenously generated FA. The no-observed-adverse-effect level for sensory irritation was 0.5 ppm and recently reconfirmed in hypo- and hypersensitive individuals. Investigation of the relationship between FA exposure and asthma or other airway effects in children showed no convincing association. In rats, repeated exposures showed no point mutation in the p53 and K-Ras genes at ≤15 ppm neither increased cell proliferation, histopathological changes and changes in gene expression at 0.7 ppm. Repeated controlled exposures (0.5 ppm with peaks at 1 ppm) did not increase micronucleus formation in human buccal cells or nasal tissue (0.7 ppm) or in vivo genotoxicity in peripheral blood lymphocytes (0.7 ppm), but higher occupational exposures were associated with genotoxicity in buccal cells and cultivated peripheral blood lymphocytes. It is still valid that exposures not inducing nasal squamous cell carcinoma in rats will not induce nasopharyngeal cancer or lymphohematopoietic malignancies in humans. Reproductive and developmental toxicity are not considered relevant in the absence of sensory irritation. In conclusion, the WHO guideline has been strengthened.

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Observations and modeling of formaldehyde at the PROPHET mixed hardwood forest site in 2008

Cited by 9 publications

References 39 publications

Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry

Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry

The role of OH production in interpreting the variability of CH₂O columns in the southeast U.S.

Recent trend in risk assessment of formaldehyde exposures from indoor air

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Observations and modeling of formaldehyde at the PROPHET mixed hardwood forest site in 2008

Cited by 9 publications

References 39 publications

Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry

Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry

The role of OH production in interpreting the variability of CH2O columns in the southeast U.S.

Recent trend in risk assessment of formaldehyde exposures from indoor air

Contact Info

Product

Resources

About

The role of OH production in interpreting the variability of CH₂O columns in the southeast U.S.