School of Earth and Environmental Sciences, Research Institute of Oceanography, Seoul National University, Seoul 08826, South Korea.
Environ Sci Technol. 2023 Jul 25;57(29):10745-10753. doi: 10.1021/acs.est.3c01084. Epub 2023 Jul 12.
Iron (Fe) is an essential micronutrient for phytoplankton growth, and its availability limits primary production in half of the global ocean. Traditionally, atmospheric input of natural mineral dust has been considered as a main source of Fe in the surface ocean. However, here we show that about 45% of the water-soluble Fe in aerosols collected over the East Sea (Japan Sea) is anthropogenic, which originates mainly from heavy fuel oil combustion, based on the analyses of various chemical tracers (Al, K, V, Ni, Pb, and Pb). It is striking that a tiny quantity of oil, less than 1% of the aerosols in mass, can constitute the majority of water-soluble Fe in aerosols due to its high Fe solubility. Furthermore, we show that a quarter of dissolved Fe in the East Sea is anthropogenic using a Pb-based scavenging model. Since this sea is almost fully enclosed (200-3000 m) and located at the forefront of the Asian human footprint, our results provide an insight that the marine Fe cycle may be already perturbed by human activities.
铁（Fe）是浮游植物生长所必需的微量元素，其可利用性限制了全球一半海洋的初级生产力。传统上，大气中自然矿物粉尘的输入被认为是海洋表面铁的主要来源。然而，在这里我们表明，在东海（日本海）采集的气溶胶中，约有 45%的水溶性铁是人为的，主要来源于重燃料油燃烧，这是基于对各种化学示踪剂（Al、K、V、Ni、Pb 和 Pb）的分析。引人注目的是，由于油的高铁溶解度，微量的油（质量不到气溶胶的 1%）可以构成气溶胶中大部分水溶性铁。此外，我们使用基于 Pb 的清除模型表明，东海四分之一的溶解铁是人为的。由于这片海域几乎完全封闭（200-3000 米），并且位于亚洲人类足迹的前沿，我们的结果表明，海洋铁循环可能已经受到人类活动的干扰。
