Jang Myoseon, Sem Karen, Choi Jiwon, Vuong Quang Tran, Pierce Richard, Blum Patricia, Javaruski James, Madhu Azad
PO Box 116450, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, 32611, USA.
PO Box 116450, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, 32611, USA.
Environ Pollut. 2025 Feb 1;366:125474. doi: 10.1016/j.envpol.2024.125474. Epub 2024 Dec 4.
Red tide is caused by the accumulation of Karenia (K.) brevis, which produces brevetoxin (BTx), a neurotoxin. Excreted BTx is incorporated into sea spray aerosol (SSA), which is created from the bursting of bubbles at the ocean's surface. For the first time, this study measures the enrichment factor of BTx in K. brevis algal aerosol. During red-tide events in 2021 and 2022, aerosol and water samples were collected from Gulf Coast beaches in Southwest Florida with various levels of K. brevis growth. The concentrations of BTx in SSA were measured using an enzyme-linked immunosorbent assay kit. The concentrations of both aerosolized BTx and organic matter (OM) were normalized using that of sodium ions and were shown to be significantly higher than those observed in seawater. Lipophilic BTx is present in SSA at concentrations that are 2-4 orders of magnitude higher than seawater, and 1-2 orders of magnitude higher than concentrations of OM in SSA. Enrichment of aerosolized BTx was also simulated in the algal culture tank with two different aerosol generation methods. The estimated activity coefficient (order of 10) of BTx in bulk seawater using the inorganic thermodynamic model indicates very poor solubility of BTx in seawater and supports its enrichment in ocean surfaces and SSA. Examining the enrichment factors of BTx and organic matter in SSA contributes to our comprehension of the potential respiratory challenges posed by inhaled algal aerosols during red tide occurrences. In addition, enriched BTx in the uppermost layer of the ocean during red tide blooms can adversely influence animals that inhabit in tide flats with neurological and respiratory impacts.
赤潮是由短裸甲藻（Karenia (K.) brevis）大量繁殖引起的，这种藻类会产生一种神经毒素——短裸甲藻毒素（BTx）。分泌出的BTx会混入海浪飞沫气溶胶（SSA）中，而海浪飞沫气溶胶是由海洋表面的气泡破裂形成的。本研究首次测量了短裸甲藻藻华气溶胶中BTx的富集因子。在2021年和2022年的赤潮事件期间，从佛罗里达州西南部墨西哥湾沿岸海滩采集了不同短裸甲藻生长水平的气溶胶和水样。使用酶联免疫吸附测定试剂盒测量了SSA中BTx的浓度。雾化BTx和有机物（OM）的浓度均通过钠离子浓度进行归一化处理，结果显示它们显著高于海水中的浓度。亲脂性BTx在SSA中的浓度比海水高2 - 4个数量级，比SSA中OM的浓度高1 - 2个数量级。还在藻类培养箱中使用两种不同的气溶胶生成方法模拟了雾化BTx的富集情况。使用无机热力学模型估算的BTx在大量海水中的活度系数（约为10）表明BTx在海水中的溶解度非常低，这支持了其在海洋表面和SSA中的富集。研究SSA中BTx和有机物的富集因子有助于我们理解赤潮期间吸入藻类气溶胶可能带来的呼吸挑战。此外，赤潮爆发期间海洋最上层富集BTx会对栖息在潮间带的动物产生不利影响，造成神经和呼吸方面的影响。
