Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Quantifying the importance of the atmospheric sink for polychlorinated dioxins and furans relative to other global loss processes.
AU - Lohmann, Rainer
AU - Jurado, Elena
AU - Dachs, Jordi
AU - Lohmann, Ulrike
AU - Jones, Kevin C.
N1 - Copyright (2006) American Geophysical Union. Further reproduction or electronic distribution is not permitted
PY - 2006/11
Y1 - 2006/11
N2 - Previous attempts to establish global mass balances for polychlorinated dioxins and furans (PCDD/Fs) have focused on the terrestrial sink, thereby neglecting deposition to the oceans and atmospheric losses. In this study, the atmospheric sink of polychlorinated dioxins and furans (PCDD/Fs) was calculated on the basis of their presence in soils. OH radical ([OH]) depletion reactions compete with atmospheric deposition fluxes for the fate of atmospheric PCDD/Fs. Three different steady state scenarios were considered: scenario A was a one-box atmosphere with globally averaged [OH], temperature (T), atmospheric lifetime (tlife), and a constant gas-particle partitioning (Φ); in scenario B, [OH], T, and Φ were averaged in a multibox atmosphere, with a constant tlife; and in scenario C, tlife was varied. In scenario A the strength of the atmospheric sink was 2400–2800 kg/yr; in scenario B it was ∼2100 kg/yr; in scenario C, it was ∼1,800 kg/yr (tlife = 5.4 days) to ∼2,800 kg/yr (tlife = 14 days). The majority of the atmospheric sink was due to the depletion of Cl4DFs (1300–1400 kg/yr), followed by Cl4DDs (360–380 kg/yr) and Cl5DFs (230–240 kg/yr). On a global scale, major sinks for PCDD/Fs are the deposition to terrestrial soils and the oceans. For Cl6–8DDs, deposition to soils outweighs depletion reactions in the atmosphere and ocean uptake. The more volatile Cl4–5DD/Fs, however, are true “multimedia” compounds, with their estimated atmospheric sink being roughly as important as the terrestrial sink (in the case of Cl5DD/Fs) or outweighing it (e.g., Cl4DD/Fs).
AB - Previous attempts to establish global mass balances for polychlorinated dioxins and furans (PCDD/Fs) have focused on the terrestrial sink, thereby neglecting deposition to the oceans and atmospheric losses. In this study, the atmospheric sink of polychlorinated dioxins and furans (PCDD/Fs) was calculated on the basis of their presence in soils. OH radical ([OH]) depletion reactions compete with atmospheric deposition fluxes for the fate of atmospheric PCDD/Fs. Three different steady state scenarios were considered: scenario A was a one-box atmosphere with globally averaged [OH], temperature (T), atmospheric lifetime (tlife), and a constant gas-particle partitioning (Φ); in scenario B, [OH], T, and Φ were averaged in a multibox atmosphere, with a constant tlife; and in scenario C, tlife was varied. In scenario A the strength of the atmospheric sink was 2400–2800 kg/yr; in scenario B it was ∼2100 kg/yr; in scenario C, it was ∼1,800 kg/yr (tlife = 5.4 days) to ∼2,800 kg/yr (tlife = 14 days). The majority of the atmospheric sink was due to the depletion of Cl4DFs (1300–1400 kg/yr), followed by Cl4DDs (360–380 kg/yr) and Cl5DFs (230–240 kg/yr). On a global scale, major sinks for PCDD/Fs are the deposition to terrestrial soils and the oceans. For Cl6–8DDs, deposition to soils outweighs depletion reactions in the atmosphere and ocean uptake. The more volatile Cl4–5DD/Fs, however, are true “multimedia” compounds, with their estimated atmospheric sink being roughly as important as the terrestrial sink (in the case of Cl5DD/Fs) or outweighing it (e.g., Cl4DD/Fs).
KW - dioxins and furans
KW - OH radical depletion
KW - gas-particle partitioning
U2 - 10.1029/2005JD006923
DO - 10.1029/2005JD006923
M3 - Journal article
VL - 111
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
SN - 0747-7309
IS - D21303
ER -