Dissolved PAHs impacted by air-sea interactions: Net volatilization and strong surface current transport in the Eastern Indian Ocean

Mengyang Liu; Haowen Zheng; Meng Chen; Junhua Liang; Mengshan Duan; Huihong Du; Mian Chen; Hongwei Ke; Kai Zhang; Minggang Cai

doi:10.1016/j.jhazmat.2022.128603

Dissolved PAHs impacted by air-sea interactions: Net volatilization and strong surface current transport in the Eastern Indian Ocean

J Hazard Mater. 2022 Jun 5:431:128603. doi: 10.1016/j.jhazmat.2022.128603. Epub 2022 Feb 28.

Authors

Mengyang Liu¹, Haowen Zheng², Meng Chen³, Junhua Liang², Mengshan Duan², Huihong Du², Mian Chen², Hongwei Ke², Kai Zhang⁴, Minggang Cai⁵

Affiliations

¹ State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; State Key Laboratory of Marine Pollution, City University of Hong Kong, 999077, Hong Kong, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
² College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
³ College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
⁴ State Key Laboratory of Marine Pollution, City University of Hong Kong, 999077, Hong Kong, China.
⁵ State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China. Electronic address: mgcai@xmu.edu.cn.

PMID: 35255333
DOI: 10.1016/j.jhazmat.2022.128603

Abstract

In the Indian Ocean, the marine fate of polycyclic aromatic hydrocarbons (PAHs) is impacted by the unique air-sea interactions with great monsoon characters. By collecting water-column samples during the monsoon transition period, we found PAHs (∑₈PAH: 1.1-27 ng L^-1) showed significantly different distributions from the Bay of Bengal, Equatorial Indian Ocean, Eastern Indian Ocean, and the South China Sea (p < 0.001). Their vertical profiles showed natural logarithm relationships with depth in the Bay of Bengal and Equatorial Indian Ocean. PAHs were mainly from wood/coal combustion and vehicle emission. The estimation of PAHs' air-seawater exchange flux revealed net volatilizations from seawater except in the Eastern Indian Ocean. The Wyrtki Jet, a surface current driven by the westerly wind, was observed in the equatorial area. This swift current could transport PAHs eastward efficiently with a mass flux of 636 ± 188 g s^-1. The subsurface current, Equatorial Undercurrent, played a less crucial role in PAHs' lateral transport with a flux of 115 ± 31.3 g s^-1. This study preliminarily revealed the role of air-sea interactions on PAHs' transport and fate in the open ocean. The coupled air-sea interactions with biogeochemical processes should be considered in future work.

Keywords: Air-sea interaction; Biomass burning; Indian Ocean; Long-range transport; Polycyclic aromatic hydrocarbons.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / analysis
China
Environmental Monitoring
Indian Ocean
Polycyclic Aromatic Hydrocarbons* / analysis
Seawater
Volatilization

Substances

Air Pollutants
Polycyclic Aromatic Hydrocarbons