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Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan

[Image: see text] Endosulfan is a persistent organochlorine pesticide that was globally distributed before it was banned and continues to cycle in the Earth system. The chemical kinetics of the gas-phase reaction of α-endosulfan with the hydroxyl radical (OH) was studied by means of pulsed vacuum UV...

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Autores principales: Alarcon, Paulo C., Kitanovski, Zoran, Padervand, Mohsen, Pöschl, Ulrich, Lammel, Gerhard, Zetzsch, Cornelius
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2023
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10603777/
https://www.ncbi.nlm.nih.gov/pubmed/37831888
http://dx.doi.org/10.1021/acs.est.3c06009
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author Alarcon, Paulo C.
Kitanovski, Zoran
Padervand, Mohsen
Pöschl, Ulrich
Lammel, Gerhard
Zetzsch, Cornelius
author_facet Alarcon, Paulo C.
Kitanovski, Zoran
Padervand, Mohsen
Pöschl, Ulrich
Lammel, Gerhard
Zetzsch, Cornelius
author_sort Alarcon, Paulo C.
collection PubMed
description [Image: see text] Endosulfan is a persistent organochlorine pesticide that was globally distributed before it was banned and continues to cycle in the Earth system. The chemical kinetics of the gas-phase reaction of α-endosulfan with the hydroxyl radical (OH) was studied by means of pulsed vacuum UV flash photolysis and time-resolved resonance fluorescence (FP-RF) as a function of temperature in the range of 348–395 K and led to a second-order rate coefficient k(OH) = 5.8 × 10(–11) exp(−1960K/T) cm(3) s(–1) with an uncertainty range of 7 × 10(–12) exp(−1210K/T) to 4 × 10(–10) exp(−2710K/T) cm(3) s(–1). This corresponds to an estimated photochemical atmospheric half-life in the range of 3–12 months, which is much longer than previously assumed (days to weeks). Comparing the atmospheric concentrations observed after the global ban of endosulfan with environmental multimedia model predictions, we find that photochemical degradation in the atmosphere is slower than the model-estimated biodegradation in soil or water and that the latter limits the total environmental lifetime of endosulfan. We conclude that the lifetimes typically assumed for soil and aquatic systems are likely underestimated and should be revisited, in particular, for temperate and warm climates.
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spelling pubmed-106037772023-10-28 Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan Alarcon, Paulo C. Kitanovski, Zoran Padervand, Mohsen Pöschl, Ulrich Lammel, Gerhard Zetzsch, Cornelius Environ Sci Technol [Image: see text] Endosulfan is a persistent organochlorine pesticide that was globally distributed before it was banned and continues to cycle in the Earth system. The chemical kinetics of the gas-phase reaction of α-endosulfan with the hydroxyl radical (OH) was studied by means of pulsed vacuum UV flash photolysis and time-resolved resonance fluorescence (FP-RF) as a function of temperature in the range of 348–395 K and led to a second-order rate coefficient k(OH) = 5.8 × 10(–11) exp(−1960K/T) cm(3) s(–1) with an uncertainty range of 7 × 10(–12) exp(−1210K/T) to 4 × 10(–10) exp(−2710K/T) cm(3) s(–1). This corresponds to an estimated photochemical atmospheric half-life in the range of 3–12 months, which is much longer than previously assumed (days to weeks). Comparing the atmospheric concentrations observed after the global ban of endosulfan with environmental multimedia model predictions, we find that photochemical degradation in the atmosphere is slower than the model-estimated biodegradation in soil or water and that the latter limits the total environmental lifetime of endosulfan. We conclude that the lifetimes typically assumed for soil and aquatic systems are likely underestimated and should be revisited, in particular, for temperate and warm climates. American Chemical Society 2023-10-13 /pmc/articles/PMC10603777/ /pubmed/37831888 http://dx.doi.org/10.1021/acs.est.3c06009 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Alarcon, Paulo C.
Kitanovski, Zoran
Padervand, Mohsen
Pöschl, Ulrich
Lammel, Gerhard
Zetzsch, Cornelius
Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan
title Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan
title_full Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan
title_fullStr Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan
title_full_unstemmed Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan
title_short Atmospheric Hydroxyl Radical Reaction Rate Coefficient and Total Environmental Lifetime of α-Endosulfan
title_sort atmospheric hydroxyl radical reaction rate coefficient and total environmental lifetime of α-endosulfan
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10603777/
https://www.ncbi.nlm.nih.gov/pubmed/37831888
http://dx.doi.org/10.1021/acs.est.3c06009
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