Zuidema Christopher, Paulsen Michael, Simpson Christopher D, Jovan Sarah E
Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105, USA; Pacific Northwest Research Station, USDA Forest Service, 400 N 34th St., Seattle, WA 98103, USA.
Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105, USA.
Sci Total Environ. 2024 Apr 20;922:171306. doi: 10.1016/j.scitotenv.2024.171306. Epub 2024 Feb 27.
Exhaust from diesel combustion engines is an important contributor to urban air pollution and poses significant risk to human health. Diesel exhaust contains a chemical class known as nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) and is enriched in 1-nitropyrene (1-NP), which has the potential to serve as a marker of diesel exhaust. The isomeric nitro-PAHs 2-nitropyrene (2-NP) and 2-nitrofluoranthene (2-NFL) are secondary pollutants arising from photochemical oxidation of pyrene and fluoranthene, respectively. Like other important air toxics, there is not extensive monitoring of nitro-PAHs, leading to gaps in knowledge about relative exposures and urban hotspots. Epiphytic moss absorbs water, nutrients, and pollutants from the atmosphere and may hold potential as an effective biomonitor for nitro-PAHs. In this study we investigate the suitability of Orthotrichum lyellii as a biomonitor of diesel exhaust by analyzing samples of the moss for 1-NP, 2-NP, and 2-NFL in the Seattle, WA metropolitan area. Samples were collected from rural parks, urban parks, residential, and commercial/industrial areas (N = 22 locations) and exhibited increasing concentrations across these land types. Sampling and laboratory method performance varied by nitro-PAH, but was generally good. We observed moderate to moderately strong correlation between 1-NP and select geographic variables, including summer normalized difference vegetation index (NDVI) within 250 m (r = -0.88, R = 0.77), percent impervious surface within 50 m (r = 0.83, R = 0.70), percent high development land use within 500 m (r = 0.77, R = 0.60), and distance to nearest secondary and connecting road (r = -0.75, R = 0.56). The relationships between 2-NP and 2-NFL and the geographic variables were generally weaker. Our results suggest O. lyellii is a promising biomonitor of diesel exhaust, specifically for 1-NP. To our knowledge this pilot study is the first to evaluate using moss concentrations of nitro-PAHs as biomonitors of diesel exhaust.
柴油内燃机排放的废气是城市空气污染的重要来源，对人类健康构成重大风险。柴油废气含有一类名为硝化多环芳烃（nitro-PAHs）的化学物质，且富含1-硝基芘（1-NP），它有可能作为柴油废气的一个标志物。同分异构的硝基多环芳烃2-硝基芘（2-NP）和2-硝基荧蒽（2-NFL）分别是芘和荧蒽光化学氧化产生的二次污染物。与其他重要的空气有毒物质一样，对硝基多环芳烃没有进行广泛监测，这导致在相对暴露情况和城市热点方面存在知识空白。附生苔藓从大气中吸收水分、养分和污染物，可能有潜力成为一种有效的硝基多环芳烃生物监测器。在本研究中，我们通过分析华盛顿州西雅图市区苔藓样本中的1-NP、2-NP和2-NFL，来研究立碗藓作为柴油废气生物监测器的适用性。样本采集于乡村公园、城市公园、居民区以及商业/工业区（共22个地点），且这些土地类型中的样本浓度呈上升趋势。采样和实验室方法的性能因硝基多环芳烃而异，但总体良好。我们观察到1-NP与选定地理变量之间存在中度到中度强的相关性，包括250米范围内的夏季归一化植被指数（NDVI）（r = -0.88，R = 0.77）、50米范围内的不透水表面百分比（r = 0.83，R = 0.70）、500米范围内的高开发土地利用百分比（r = 0.77，R = 0.60）以及到最近二级道路和连接道路的距离（r = -0.75，R = 0.56）。2-NP和2-NFL与地理变量之间的关系通常较弱。我们的结果表明立碗藓是一种很有前景的柴油废气生物监测器，特别是对于1-NP。据我们所知，这项初步研究是首次评估利用苔藓中硝基多环芳烃的浓度作为柴油废气生物监测器。
