Polychlorinated Naphthalenes and Coplanar Polychlorinated Biphenyls in Arctic Air

Abstract

Concentrations of polychlorinated naphthalenes (PCNs) are reported for the first time in arctic air. The data represent combined air samples from the Barents Sea (n = 2), eastern Arctic Ocean (n = 10), Norwegian Sea (n = 2), and two land-based monitoring stations at Alert, Canada (n = 5), and Dunai Island in eastern Siberia, Russia (n = 3). Values for ∑PCN (pg m-3) were 6−49 for shipboard samples and 0.3−8 for land-based stations and were dominated by the 3-Cl and 4-Cl homologues, which accounted for 90−95% of the total mass. Average values for ∑PCB (pg m-3) for the shipboard samples were 126, 24, and 75 for the Barents Sea, eastern Arctic, and Norwegian Sea, respectively. Three-dimensional 5-day air parcel back-trajectories arriving at the ship at 850 and 925 hPa suggested that elevated PCB and PCN concentrations for shipboard samples originated in Europe. Concentrations (fg m-3) of coplanar PCBs in artic air were 3−40 (PCB 77) and 0.3−8 (PCB 126)about an order of magnitude lower than in urban air. Higher concentrations of PCB 77 and PCB 126, 347 and 5.0 (fg m-3), respectively, were found in the Barents Sea for two samples with elevated ∑PCBs. The proportion of coplanar PCBs to ∑PCBs was within the range of values reported for Aroclor and Clophen mixtures. The 2,3,7,8-TCDD toxicity of the air samples was assessed in terms of the TEQ (dioxin toxic equivalents) contribution of mono-ortho PCBs (congeners 105, 114, 118, 156), non-ortho (coplanar) PCBs (congeners 77 and 126), and dioxin-like PCNs for which toxic equivalent factors have been determined. The results show a 13−67% TEQ contribution of PCNs in arctic air, and it is concluded that further investigation of this compound class is merited.

Polychlorinated naphthalenes in the air over the equatorial Indian Ocean: Occurrence, potential sources, and toxicity

“…Being consistent to the spatial pattern of PCN concentrations, TEQ values of samples 11 and 13 were higher than others. Compared with other studies, TEQs were slightly higher than those in the arctic air monitoring stations (0.0001-0.0455 fg m − 3 ) (Helm et al, 2004), and considerably lower than those reported for the Barents Sea (0.99 fg m −3 ), the Norwegian Sea (0.36 fg m −3 ), and the eastern Arctic Ocean (0.548 fg m −3 ) (Harner et al, 1998). Much higher TEQ values have been estimated for the air in adjacent countries such as Pakistan and India (Mahmood et al, 2014;Xu et al, 2014).…”

“…Thus, it is important to monitor marine POP pollution status and estimate their sources. Several studies have been carried out to investigate PCN levels in air, sediments, or organisms of the arctic and subarctic oceans and seas (Falandysz and Rappe, 1996;Harner et al, 1998;Lundgren et al, 2002Lundgren et al, , 2003Bidleman et al, 2010).…”

Levels and spatial distribution of gaseous polychlorinated biphenyls and polychlorinated naphthalenes in the air over the northern South China Sea

“…Although the production of PCBs and PCNs has been banned or severely restricted since the 1970s and 1980s, products containing these formulations are still present in the environment (Bidleman et al, 2010;Breivik et al, 2007). In the past two decades, there have been several investigations on the levels, distribution and fate of gaseous PCBs and PCNs in the atmosphere (Falandysz, 1998;Harner et al, 1998;Jaward et al, 2004a;Lee et al, 2007;Mari et al, 2008). The recent researches indicate that historical usage, e-waste and shipwreck are major sources of PCBs (Breivik et al, 2002b;Breivik et al, 2011;Gioia et al, 2011).…”

In vitro assay for human thyroid hormone receptor β agonist and antagonist effects of individual polychlorinated naphthalenes and Halowax mixtures

“…This indicates that the lighter congeners show greater potential to disrupt the thyroid system, which is different from their dioxin-like activities. Of note, most of the PCNs present in air are the lighter congeners; trichlorinated and tetrachlorinated naphthalenes account for approximately 80% and 90-95% of the total PCN mass in ambient and arctic air, respectively, based on air sampling of PCNs in the United Kingdom, and it was concluded that air masses from the United Kingdom and Europe may be influencing PCN burdens more than PCBs [28,29]. Thus, the thyroid-disrupting effects of the lighter congeners may cause severe adverse effects in human acting via airborne exposure.…”