 |
| Titel |
Establishing the contribution of lawn mowing to atmospheric aerosol levels in American suburbs |
| VerfasserIn |
R. M. Harvey, J. Zahardis, G. A. Petrucci |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 2 ; Nr. 14, no. 2 (2014-01-23), S.797-812 |
| Datensatznummer |
250118306
|
| Publikation (Nr.) |
 copernicus.org/acp-14-797-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
Green leaf volatiles (GLVs) are a class of wound-induced volatile organic
compounds emitted by several plant species. Turf grasses emit a complex
profile of GLVs upon mowing, as evidenced by the "freshly cut grass" smell,
some of which are readily oxidized in the atmosphere to contribute to
secondary organic aerosol (SOA). The contribution of lawn-mowing-induced SOA
production may be especially impactful at the urban–suburban interface, where
urban hubs provide a source of anthropogenic oxidants and SOA while suburban
neighborhoods have the potential to emit large quantities of reactive,
mow-induced GLVs. This interface provides a unique opportunity to study
aerosol formation in a multicomponent system and at a regionally relevant
scale. Freshly cut grass was collected from a study site in Essex Junction,
Vermont, and was placed inside a 775 L Teflon experimental chamber. Thermal
desorption gas chromatography–mass spectrometry (TD-GC/MS) was used to
characterize the emitted GLV profile. Ozone was introduced to the
experimental chamber and TD-GC/MS was used to monitor the consumption of
these GLVs and the subsequent evolution of gas-phase products, while a
scanning mobility particle sizer was used to continuously measure aerosol
size distributions and mass loadings as a result of grass clipping
ozonolysis.
Freshly cut grass was found to emit a complex mixture of GLVs, dominated by
\textit{cis}-3-hexenyl acetate (CHA) and \textit{cis}-3-hexenol (HXL), which
were released at an initial rate of 1.8 (± 0.5) μg and 0.07
(± 0.03) μg per square meter of lawn mowed with each mowing.
Chamber studies using pure standards of CHA and HXL were found to have
aerosol yields of 1.2 (± 1.1)% and 3.3 (± 3.1)%,
respectively. Using these aerosol yields and the emission rate of CHA
and HXL by grass, SOA evolution by ozonolysis of grass clippings was
predicted. However, the measured SOA mass produced from the ozonolysis of
grass clippings exceeded the predicted amount, by upwards of
~150%. The ozonolysis of a mixture of CHA and HXL
representative of environmental mixing ratios also failed to accurately model
the SOA mass produced by grass clippings. The disparity between measured SOA
mass and the predicted SOA mass suggests that grass clippings contain other
SOA precursors in addition to CHA and HXL.
Aerial photographs and geospatial analysis were used to determine the area of
turfgrass coverage in a suburban neighborhood, which was then used along with
measured SOA production as a function of grass mowed to determine that lawn
mowing has the potential to contribute 47 μg SOA per m−2 of
lawn to the atmosphere per mowing event by ozonolysis, which cannot be
modeled solely by the ozonolysis of CHA, HXL or a representative mixture of
the two. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|