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| Titel |
Ozone and secondary organic aerosol production by interaction between and organophosphorous pesticide and biogenic VOCs mixture |
| VerfasserIn |
Esther Borrás, Mila Ródenas, Teresa Vera, Amalia Muñoz |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250146560
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| Publikation (Nr.) |
 EGU/EGU2017-10588.pdf |
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| Zusammenfassung |
| Pesticides are the chemical compounds most widely used worldwide, and their toxicological
characteristics can have harmful effects on human health.
The entry into the atmosphere of pesticides occurs during application or subsequent
processes. Once they are emitted, they can be distributed in the gas phase or particulate phase.
However, most of them are in both phases, since they are semi-volatile compounds. As with
other organic compounds, pesticides’ removal in the atmosphere can be mainly
accomplished by wet or dry deposition, by photolysis or by reaction with hydroxyl radicals
(OH), nitrate radicals (NO3) and ozone (O3) [1]. All these processes give rise to the
formation of other products, which could become more harmful than the starting
compounds. It is therefore necessary to know all these processes to estimate the
impact of pesticides in the atmosphere. In addition, it is important to study how the
pesticides interact with organic compounds naturally emitted by crops and their
possible impact on the formation of secondary organic aerosols, ozone and other
compounds.
In this work, the gas phase atmospheric degradation of an organothiophosphate
insecticide has been investigated at the large outdoor European Photoreactor (EUPHORE) in
the presence of a biogenic compound mixture typical from orange trees emissions. Its
photolysis has been studied under sunlight conditions, in the presence of different
concentration ratios of chlorpyrifos and biogenic VOCs mixture and in the absence of initial
inorganic seeds. Reaction with ozone has also been studied.
Gaseous phase compounds were determined by a Fourier Transform Infrared
Spectrometer (FTIR), Proton Transfer Reaction – Mass Spectrometry (PTRMS), Solid Phase
Microextraction (SPME) coupled to gas chromatography-mass spectrometry (GCMS) and
NOx, O3 and SO2 monitors. Aerosol mass concentration was measured using a scanning
mobility particle sizer (SMPS) and a tapered element oscillating monitor (TEOM). Chemical
characterization of degradation products were done by using different off-line analysis with
SPME, C18 cartridges and filters plus derivatization and subsequent analysis by
GCMS.
The results show that the combination of pesticide and biogenic compounds increase the
SOA and O3 formation, being, in combination, high contributors to photochemical
smog.
This study contributes providing useful data about atmospheric degradation processes of
pesticides. Knowledge of the specific degradation products, including the formation of
secondary particulate matter and ozone, could complete the assessment of their potential
impact. The understanding of atmospheric reactions should help to estimate the expected
formation of gas and/or particulate products in the troposphere for each pesticide. Hence,
these results can contribute to the selection of environmentally sustainable strategies against
plagues.
Acknowledgements
The authors wish to thank the EUPHORE staff. Ministerio de Economía y
Competitividad for IMPLACAVELES (CGL2013-49093-C2-1-R) and Generalitat Valenciana
for the DESESTRES- Prometeo II project are acknowledged. Fundación CEAM is partly
supported by Generalitat Valenciana – Spain.
References
[1] R. Atkinson, et al. Water, Air and Soil Pollution 115, 219-243 (1999). |
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