Spatial Distributions and Seasonal Changes of Current‐Use Pesticides from the North Pacific to the Arctic Oceans

Abstract

Distributions of eight targeted current‐use pesticides (CUPs) chloroneb, simazine, atrazine, alachlor, dacthal, chlorobenzilate, methoxychlor, and permethrin were investigated in seawater and the atmosphere in a region covering the North Pacific to the Arctic Oceans during the 7th and 8th Chinese National Arctic Research Expedition (2016 and 2017) voyages of the research vessel R/V Xuelong (Snow Dragon in English). Total CUP concentrations in seawater have prominent seasonal and latitudinal trends, with higher concentrations occurring at lower latitudes in early summer. The major contributors of the CUPs (∑8CUP) did not alter over different seasons with dominant chloroneb, alachlor, and atrazine accounting for more than 90%, but their concentrations did have marked seasonal changes. However, the compositions of the eight analyzed CUPs varied indistinctly between seasons indicating a possible combined environmental impact on these compounds rather than the effects of individual chemical properties. Three‐day backward air mass trajectories indicate that atmospheric masses from northeastern China are responsible for the high concentrations of CUPs in East China and Japan Seas, whereas those from the North Atlantic Ocean contribute to the low levels in local area. Fugacity ratios indicate potential volatilization and equilibrium of chloroneb in the Canada Basin of the Arctic Ocean and Japan Sea, respectively, and deposition of other CUPs in both regions. However, atmospheric concentrations are decoupled from those in seawater, which indicates a low exchange rate.

Polycyclic Aromatic Hydrocarbons in the Marine Atmosphere from the Western Pacific to the Southern Ocean: Spatial Variability, Gas/Particle Partitioning, and Source Apportionment

“…The labeled and target analytes in this study are detailed in Text S1 and Table S2. XAD columns were processed using high-volume SPE ISIU technology, , see Text S2 for more information. Briefly, XAD was placed in a stainless-steel tube, 45 mL of mixed solvent (acetone (ACE):dichloromethane (DCM): n -hexane (HEX) (1:1:1, v/v/v)) was added and then ultrasonic extraction for 5 min.…”

Seasonal Variation of Legacy Organochlorine Pesticides (OCPs) From East Asia to the Arctic Ocean

“…Ninety surface seawater (stations A01–A74 and B01–B16) and 16 atmospheric samples (stations C01–C16) were collected from East Asia to the Arctic Ocean during voyages of the Chinese research vessel Xue Long ( Snow Dragon ) during the 7th and 8th Chinese National Arctic Research Expeditions of 12 July to 23 September 2016 and 27 July to 7 October 2017 (support information (SI) Tables S1–S3 and Figures S1 and S2). Seawater and atmospheric samples were concentrated in a shipborne laboratory using a high‐volume solid‐phase extraction method with the in situ internal ultrasonic (high‐volume SPE ISIU) treatment (Cai, 2017a, 2017b, 2018; Gao et al, 2019; Zhang et al, 2020) (Text S1 and Figure S3). Detailed descriptions of the sampling and concentration processes are given in Text S2a‐S2e and Figure S4 of the SI.…”

Method Development for Low-Concentration PAHs Analysis in Seawater to Evaluate the Impact of Ship Scrubber Washwater Effluents

“…The distribution of PAHs concentrations in seawater in different regions of the world shows that nearshore seas with anthropogenic influence are higher than the adjacent sea and oceanic areas. The concentrations of dissolved PAHs in seawater are gradually diluted and diffused into the offshore and far seas with the input of land and coastal anthropogenic activities [32][33][34].…”