Aubourg Matthew A, Livi Kenneth J T, Sawtell Gregory G, Sanchez-Gonzalez Carlos C, Spada Nicholas J, Dickerson Russell R, Chiou Wen-An, Kamanzi Conchita, Ramachandran Gurumurthy, Rule Ana M, Heaney Christopher D
Community Science and Innovation for Environmental Justice (CSI EJ) Initiative, Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, United States; Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, United States.
Materials Characterization and Processing, Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21211, United States.
Sci Total Environ. 2024 Dec 20;957:176842. doi: 10.1016/j.scitotenv.2024.176842. Epub 2024 Oct 11.
Despite decreasing US consumption, over 90 million metric tons of coal were exported by the US in 2023, requiring significant infrastructure for transport, handling, and storage of coal at export terminals. Residents in Curtis Bay, Baltimore, Maryland, USA live at the fenceline of an open-air coal terminal and have, for decades, reported rapid accumulation of black dust at their homes. Community-level exposure to coal dust originating from coal handling and storage terminals has remained largely unexplored.
To investigate community-identified concerns and use a community-driven approach to determine the presence/absence of coal dust on Curtis Bay surfaces.
Passive settled dust samples were collected from two residential areas, 345 m and 1235 m from the coal terminal, using conductive carbon tape. Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX) of standard reference coal material and positive control material from the coal terminal in Curtis Bay were used to optimize the morphological and elemental classification criteria for coal dust. A manual SEM-EDX protocol was developed to identify coal particles in settled dust collected on conductive carbon tape in community settings.
SEM-EDX analysis confirmed presence of coal dust sampled at both residential locations. Estimated coal dust particle loading at the proximal and distal site were 13.2 and 3.4 coal particles/mm, respectively. The coal dust particles identified met specific criteria, including size (>5 μm), morphology, and elemental composition (≥75 % carbon, ≤20 % oxygen).
These findings are consistent with longstanding community concerns and lived experiences regarding the presence of coal dust in Curtis Bay, which neighbors a major open-air coal terminal. This approach has potential for other communities neighboring coal terminals to assess similar concerns with residential coal dust exposure.
尽管美国的煤炭消费量在下降，但2023年美国仍出口了超过9000万吨煤炭，这需要在出口码头建设大量用于煤炭运输、装卸和储存的基础设施。美国马里兰州巴尔的摩市柯蒂斯湾的居民居住在一个露天煤炭码头的围栏边，几十年来，他们报告说家中黑尘迅速堆积。社区层面接触源自煤炭装卸和储存码头的煤尘情况在很大程度上仍未得到研究。
调查社区确定的问题，并采用社区驱动的方法来确定柯蒂斯湾地表是否存在煤尘。
使用导电碳带从距离煤炭码头345米和1235米的两个居民区采集被动沉降灰尘样本。利用柯蒂斯湾煤炭码头的标准参考煤材料和阳性对照材料的扫描电子显微镜和能量色散X射线光谱（SEM-EDX）来优化煤尘的形态和元素分类标准。制定了一份手动SEM-EDX方案，以识别在社区环境中导电碳带上收集的沉降灰尘中的煤颗粒。
SEM-EDX分析证实了在两个居住地点采集的样本中存在煤尘。近端和远端地点估计的煤尘颗粒负荷分别为13.2和3.4个煤颗粒/平方毫米。识别出的煤尘颗粒符合特定标准，包括尺寸（>5微米）、形态和元素组成（碳≥75%，氧≤20%）。
这些发现与社区长期以来对柯蒂斯湾存在煤尘的担忧和实际经历一致，柯蒂斯湾与一个主要的露天煤炭码头相邻。这种方法有可能用于其他临近煤炭码头的社区，以评估居民对煤尘暴露的类似担忧。
