Plaas Haley E, Paerl Ryan W, Baumann Karsten, Karl Colleen, Popendorf Kimberly J, Barnard Malcolm A, Chang Naomi Y, Curtis Nathaniel P, Huang Hwa, Mathieson Olivia L, Sanchez Joel, Maizel Daniela J, Bartenfelder Amy N, Braddy Jeremy S, Hall Nathan S, Rossignol Karen L, Sloup Randolph, Paerl Hans W
UNC-Chapel Hill, Earth, Marine, and Environmental Sciences, Institute of Marine Sciences, 3431 Arendell St., Morehead City, NC 28577, United States of America; UNC-Chapel Hill, Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, 135 Dauer Dr., Chapel Hill, NC 27599, United States of America.
North Carolina State University, Department of Marine, Earth, and Atmospheric Sciences, Jordan Hall, 2800 Faucette Dr., Raleigh, NC 27607, United States of America.
Sci Total Environ. 2022 Dec 15;852:158383. doi: 10.1016/j.scitotenv.2022.158383. Epub 2022 Sep 1.
In addition to obvious negative effects on water quality in eutrophic aquatic ecosystems, recent work suggests that cyanobacterial harmful algal blooms (CHABs) also impact air quality via emissions carrying cyanobacterial cells and cyanotoxins. However, the environmental controls on CHAB-derived aerosol and its potential public health impacts remain largely unknown. Accordingly, the aims of this study were to 1) investigate the occurrence of microcystins (MC) and putatively toxic cyanobacterial communities in particulate matter ≤ 2.5 μm in diameter (PM), 2) elucidate environmental conditions promoting their aerosolization, and 3) identify associations between CHABs and PM concentrations in the airshed of the Chowan River-Albemarle Sound, an oligohaline, eutrophic estuary in eastern North Carolina, USA. In summer 2020, during peak CHAB season, continuous PM samples and interval water samples were collected at two distinctive sites for targeted analyses of cyanobacterial community composition and MC concentration. Supporting air and water quality measurements were made in parallel to contextualize findings and permit statistical analyses of environmental factors driving changes in CHAB-derived aerosol. MC concentrations were low throughout the study, but a CHAB dominated by Dolichospermum occurred from late June to early August. Several aquatic CHAB genera recovered from Chowan River surface water were identified in PM during multiple time points, including Anabaena, Aphanizomenon, Dolichospermum, Microcystis, and Pseudanabaena. Cyanobacterial enrichment in PM was indistinctive between subspecies, but at one site during the early bloom, we observed the simultaneous enrichment of several cyanobacterial genera in PM. In association with the CHAB, the median PM mass concentration increased to 8.97 μg m (IQR = 5.15), significantly above the non-bloom background of 5.35 μg m (IQR = 3.70) (W = 1835, p < 0.001). Results underscore the need for highly resolved temporal measurements to conclusively investigate the role that CHABs play in regional air quality and respiratory health risk.
除了对富营养化水生生态系统的水质有明显负面影响外，近期研究表明，蓝藻有害藻华（CHABs）还通过携带蓝藻细胞和蓝藻毒素的排放物影响空气质量。然而，关于源自CHABs的气溶胶的环境控制及其对公众健康的潜在影响仍 largely未知。因此，本研究的目的是：1）调查直径≤2.5μm的颗粒物（PM）中微囊藻毒素（MC）的存在情况以及假定有毒的蓝藻群落；2）阐明促进它们气溶胶化的环境条件；3）确定在美国北卡罗来纳州东部一个低盐度、富营养化的河口——乔万河-阿尔伯马尔湾流域中，CHABs与PM浓度之间的关联。2020年夏季，在CHAB高发季节，在两个不同地点采集了连续的PM样本和间隔水样，用于针对性分析蓝藻群落组成和MC浓度。同时进行了配套的空气和水质测量，以将研究结果置于背景中，并对驱动源自CHABs的气溶胶变化的环境因素进行统计分析。在整个研究过程中，MC浓度较低，但从6月下旬到8月初出现了以多列藻为主的CHAB。在多个时间点的PM中鉴定出了从乔万河地表水回收的几种水生CHAB属，包括鱼腥藻属、束丝藻属、多列藻属、微囊藻属和伪鱼腥藻属。PM中蓝藻的富集在亚种之间不明显，但在早期藻华期间的一个地点，我们观察到PM中几种蓝藻属同时富集。与CHAB相关，PM质量浓度中位数增加到8.97μg/m（四分位距=5.15），显著高于非藻华背景值5.35μg/m（四分位距=3.70）（W=1835，p<0.001）。结果强调了需要进行高分辨率的时间测量，以最终确定CHABs在区域空气质量和呼吸健康风险中所起的作用。
