Targino Admir Créso, da Costa Camila Couto, Krecl Patricia
Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil.
Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil.
Heliyon. 2025 Jan 3;11(2):e41697. doi: 10.1016/j.heliyon.2025.e41697. eCollection 2025 Jan 30.
Urban bus commuters are exposed to a range of traffic-related air pollutants, including black carbon (BC) particles, a major hazardous component of vehicle exhaust emissions. This study provides the first assessment of in-cabin BC concentrations aboard diesel-fuelled public buses in Montevideo, Uruguay. Our objective was to assess BC concentrations during evening peak commuting hours and to examine how specific traffic elements, such as bus stops, traffic lights and traffic volume, influence exposure levels. We implemented a structured sampling strategy to maximise the reliability of our findings by collecting data during four consecutive weekdays within the same timeframe (17:00-18:00 h) in May 2019. We measured BC concentrations at a high-frequency sampling rate using a handheld aethalometer, focusing on two bus routes. The mean in-cabin BC concentration was 14.28 ± 14.38 μg m⁻³, with considerable spatial variability. Notably, BC concentrations were significantly higher at traffic lights and bus stops, where stop-and-go driving patterns and idling contribute to increased emissions, while the constant opening and closing of doors allows outside air to infiltrate. We found a positive trend between traffic volume and median BC concentrations, consistent with previous studies conducted in other cities. Compared to similar studies in South America, BC concentrations were found to be intermediate, but considerably higher than those observed in North American and European cities. This study underscores the importance of implementing targeted interventions in urban transport policies, specifically addressing congestion points, like bus stops and traffic lights, to effectively reduce commuter exposure to harmful air pollutants. Whilst our study focused on Montevideo, interventions to combat traffic-related air pollutants should be expanded across Latin American cities, where reliance on diesel-powered public transportation remains prevalent.
城市公交通勤者会接触到一系列与交通相关的空气污染物,包括黑碳(BC)颗粒,这是车辆尾气排放中的一种主要有害成分。本研究首次评估了乌拉圭蒙得维的亚柴油公交客车车厢内的黑碳浓度。我们的目标是评估傍晚高峰通勤时段的黑碳浓度,并研究公交站点、交通信号灯和交通流量等特定交通因素如何影响暴露水平。我们实施了一种结构化采样策略,通过在2019年5月的同一时间段(17:00 - 18:00)内连续四个工作日收集数据,以最大限度地提高研究结果的可靠性。我们使用手持式黑碳仪以高频采样率测量黑碳浓度,重点关注两条公交线路。车厢内黑碳浓度的平均值为14.28±14.38μg m⁻³,空间变异性较大。值得注意的是,在交通信号灯处和公交站点,黑碳浓度显著更高,在这些地方,走走停停的驾驶模式和怠速会导致排放量增加,同时车门的不断开关会使外部空气渗入。我们发现交通流量与黑碳浓度中位数之间呈正相关趋势,这与之前在其他城市进行的研究一致。与南美洲的类似研究相比,黑碳浓度处于中等水平,但远高于在北美和欧洲城市观察到的浓度。本研究强调了在城市交通政策中实施针对性干预措施的重要性,特别是解决公交站点和交通信号灯等拥堵点,以有效减少通勤者接触有害空气污染物。虽然我们的研究聚焦于蒙得维的亚,但应对与交通相关空气污染物的干预措施应扩展到整个拉丁美洲城市,在这些城市,对柴油动力公共交通的依赖仍然普遍。