Iodine and Halocarbon Response of Laminaria digitata to Oxidative Stress and Links to Atmospheric New Particle Production
Iodine and Halocarbon Response of Laminaria digitata to Oxidative Stress and Links to Atmospheric New Particle Production
复制标题
指状海带对氧化应激的碘和卤化碳响应以及与大气新颗粒产生的联系
DOI：
10.1071/en05078
复制
发表时间：
2005
影响因子：
4.3
通讯作者：
G. Mcfiggans
中科院分区：
文献类型：
--
作者：
C. Palmer;Thorsten Anders;L. Carpenter;F. Küpper;G. Mcfiggans
环境背景.各种有机碘化合物（包括CH 3 I、CH 2ClI、CH 2BrI、CH 2 I2）存在于整个海洋边界层，这是海藻、浮游植物和海水中发生的光解反应产生的结果。在空气中，这些化合物迅速光解产生原子I，随后与臭氧反应形成氧化碘，可能导致对流层氧化能力的扰动和大气颗粒的成核。最近的研究已经确定分子碘是沿海地区碘原子的另一个来源。在这里，我们研究的相对作用和控制的气态有机和分子碘释放的海藻海带。摘要。研究了棕色海藻海带对不同化学胁迫的响应中卤碳、I2和颗粒产生的变化。氧化应激（由外源性过氧化氢、气态臭氧或寡古洛糖醛酸盐溶液（已知的氧化应激诱导剂）引起）导致海藻产生的卤烃和I2增加。最大的I2释放下观察到暴露于O3（在几十亿分之一的体积（ppbv）），而oligoguluronates引起最高的释放含碘的卤代烃，包括CH 2 I2。显着更大的生产I2相比，CH 2 I2，观察到在大气臭氧水平。只有当海带样品暴露于臭氧时才观察到颗粒产生（每克鲜重（FW）的I2光降解速率可达16000 cm-3s-1，停留时间约2 min，I2光降解总通量为1.6 × 108 cm-3s-1g-1FW）;使不含O3的空气通过未受应力的海藻，随后与臭氧进行二次混合，不会导致任何可测量的颗粒形成。我们有限的数据表明，臭氧elaboratoic非生物生产的I2从海带，有一个直接的关系，I2释放量和形成的颗粒数量。结果支持最近的假设，分子碘，而不是挥发性有机碘（如CH 2 I2）从暴露的海藻释放是沿海新粒子生产的主要来源。
Environmental Context.Various organic iodine compounds (including CH3I, CH2ClI, CH2BrI, CH2I2) are present throughout the marine boundary layer as a result of their production from seaweeds, phytoplankton, and photolysis reactions occurring in seawater. In air, these compounds rapidly photolyse to give atomic I which subsequently reacts with ozone to form iodine oxide, potentially leading to perturbations of the tropospheric oxidative capacity and nucleation of atmospheric particles. Recent research has identified molecular iodine as an additional source of iodine atoms to coastal areas. Here we study the relative roles and controls of gaseous organic and molecular iodine release from the seaweed Laminaria digitata. Abstract.Changes in the halocarbon, I2 and particle production of the brown algal kelp Laminaria digitata as a response to different chemical stresses have been investigated. Oxidative stress (caused by either exogenous hydrogen peroxide, gaseous ozone or a solution of oligoguluronates, known elicitors of oxidative stress) caused increased halocarbon and I2 production by the seaweed. The maximum I2 release was observed under exposure to O3 (at several hundred parts per billion by volume (ppbv)), whereas oligoguluronates elicited the highest release of iodine-containing halocarbons including CH2I2. Significantly greater production of I2, compared to CH2I2, was observed at atmospheric levels of ozone. Particle production was observed only when the Laminaria samples were exposed to ozone (up to 16 000 cm-3 s-1 per gram fresh weight (FW) of seaweed with a ~2 min residence time and with a total I atom flux of 1.6 × 108 cm-3 s-1 g-1 FW from photolysis of I2); passing O3-free air over the unstressed seaweed followed by secondary mixing with ozone did not result in any measurable particle formation. Our limited data indicate that ozone elicits abiotic production of I2 from Laminaria and that there is a direct relationship between the amount of I2 released and the number of particles formed. The results support the recent hypothesis that molecular iodine rather than volatile organic iodine (e.g. CH2I2) release from exposed seaweeds is the major source of coastal new particle production.