Axel Möller

The occurrence, distribution, and temperature dependence in the marine atmosphere of several alternative brominated flame retardants (BFRs), Dechlorane Plus (DP) and polybrominated diphenyl ethers (PBDEs) were investigated during a sampling cruise from the East Indian Archipelago toward the Indian Ocean and further to the Southern Ocean. Elevated concentrations were observed over the East Indian Archipelago, especially of the non-PBDE BFR hexabromobenzene (HBB) with concentrations up to 26 pg m^–3 which were found to be related to continental air masses from the East Indian Archipelago. Other alternative BFRs— pentabromotoulene (PBT), pentabromobenzene (PBBz), and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE)—were elevated, too, with concentrations up to 2.8, 4.3, and 2.3 pg m^–3, respectively. DP was detected from 0.26 to 11 pg m^–3 and bis-(2-ethylhexyl)-tetrabromophthalate (TBPH) ranged from not detected (nd) to 2.8 pg m^–3, respectively. PBDEs ranged from nd to 6.6 pg m^–3 (Σ₁₀PBDEs) with the highest individual concentrations for BDE-209. The approach of Clausius–Clapeyron (CC) plots indicates that HBB is dominated by long-range atmospheric transport at lower temperatures over the Indian and Southern Ocean, while volatilization processes and additional atmospheric emissions dominate at higher temperatures. In contrast, BDE-28 and -47 are dominated by long-range transport without fresh emissions over the entire cruise transect and temperature range, indicating limited fresh emissions of the meanwhile classic PBDEs.

Organophosphorus compounds (OPs) being applied as flame retardants and plasticizers were investigated in airborne particles over the Pacific, Indian, Arctic, and Southern Ocean. Samples taken during two polar expeditions in 2010/11, one from East Asia to the high Arctic (CHINARE 4) and another from East Asia toward the Indian Ocean to the Antarctic (CHINARE 27), were analyzed for three halogenated OPs (tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCPP) and tris(1,3-dichloro-2-isopropyl) phosphate (TDCP)), four alkylated OPs (tri-n-butyl phosphate (TnBP), tri-iso-butyl phosphate (TiBP), tris(2-butoxyethyl)phosphate (TBEP), and tris(2-ethylhexyl) phosphate (TEHP)), and triphenyl phosphate (TPhP). The sum of the eight investigated OPs ranged from 230 to 2900 pg m^–3 and from 120 to 1700 pg m^–3 during CHINARE 4 and CHINARE 27, respectively. TCEP and TCPP were the predominating compounds, both over the Asian seas as well as in the polar regions, with concentrations from 19 to 2000 pg m^–3 and 22 to 620 pg m^–3, respectively. Elevated concentrations were observed in proximity to the Asian continent enhanced by continental air masses. They decreased sharply toward the open oceans where they remained relatively stable. This paper shows the first occurrence of OPs over the global oceans proving that they undergo long-range atmospheric transport over the global oceans toward the Arctic and Antarctica.

Marine boundary layer air and seawater samples taken during a polar expedition cruise from East China Sea to the Arctic were analyzed in order to compare the occurrence, distribution, and fate of the banned polybrominated diphenyl ethers (PBDEs) with their brominated alternatives as well as the chlorinated Dechloranes. The sum of PBDEs (∑₁₀PBDEs) in the atmosphere ranged from 0.07 to 8.1 pg m^–3 with BDE–209 being the dominating congener and from not detected (n.d.) to 0.6 pg L^–1 in seawater. Alternate brominated flame retardants (BFRs), especially hexabromobenzene (HBB), (2,3–dibromopropyl–2,4,6–tribromophenyl ether (DPTE), pentabromotoluene (PBT), 2–ethylhexyl 2,3,4,5–tetrabromobenzoate (EHTBB), bis–(2–ethylhexyl)–tetrabromophthalate (TBPH), were detected in higher concentrations than PBDEs, even in the high Arctic (0.6 to 15.4 pg m^–3 for sum of alternate BFRs), indicating the change of PBDEs toward alternate BFRs in the environmental predominance. In addition, Dechlorane Plus (DP) as well as Dechlorane 602, 603, and 604 were detected both in the atmosphere and in seawater. The highest concentrations as well as the highest compound variability were observed in East Asian samples suggesting the Asian continent as source of these compounds in the marine environment. The air–seawater exchange indicates strong deposition, especially of alternate BFRs, as well as dry particle–bound deposition of BDE–209 into the ocean.