Road traffic is one of the main sources of particulate matter (PM) in the atmosphere. Despite its importance, there are significant challenges in the quantitative evaluation of its contribution to airborne concentrations. In order to propose effective mitigation scenarios, the proportions of PM traffic emissions, whether they are exhaust or non-exhaust emissions, should be evaluated for any given geographical location. In this work, we report on the first study to evaluate particulate matter emissions from all registered heavy duty diesel vehicles in Qatar. The study was applied to an active traffic zone in urban Doha. Dust samples were collected and characterized for their shape and size distribution. It was found that the particle size ranged from few to 600 μm with the dominance of small size fraction (less than 100 μm). In-situ elemental composition analysis was conducted for side and main roads traffic dust, and compared with non-traffic PM. The results were used for the evaluation of the enrichment factor and preliminary source apportionment. The enrichment factor of anthropogenic elements amounted to 350. The traffic source based on sulfur elemental fingerprint was almost 5 times higher in main roads compared with the samples from non-traffic locations. Moreover, PM exhaust and non-exhaust emissions (tyre wear, brake wear and road dust resuspension) were evaluated. It was found that the majority of the dust was generated from tyre wear with 33% followed by road dust resuspension (31%), brake wear (19%) and then exhaust emissions with 17%. The low contribution of exhaust PM10 emissions was due to the fact that the majority of the registered vehicle models were recently made and equipped with efficient exhaust PM reduction technologies.Implication: This study reports on the first results related to the evaluation of PM emission from all registered diesel heavy duty vehicles in Qatar. In-situ XRF elemental analysis from main, side roads as well as non-traffic dust samples was conducted. Several characterization techniques were implemented and the results show that the majority of the dust was generated from tyre wear, followed by road dust resuspension and then brake wear; whereas exhaust emissions were tremendously reduced since the majority of the registered vehicle models were recently made and equipped with efficient exhaust PM reduction technologies. This implies that policy makers should place stringent measures on old vehicle license renewals and encourage the use of metro and public transportation.

中文翻译：

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对卡塔尔非乘员柴油车辆的颗粒物排放进行评估。

道路交通是大气中颗粒物（PM）的主要来源之一。尽管它很重要，但是在定量评估其对空气中浓度的贡献方面仍然存在重大挑战。为了提出有效的缓解方案，应针对任何给定地理位置评估PM交通排放的比例，无论是废气排放还是非废气排放。在这项工作中，我们报告了第一项评估卡塔尔所有注册重型柴油车辆的颗粒物排放的研究。该研究被应用于多哈市区的一个活跃交通区域。收集灰尘样品并对其形状和尺寸分布进行表征。发现粒径范围从几微米到600微米，主要是小尺寸部分（小于100微米）。对侧边和主要道路的交通粉尘进行了原位元素组成分析，并与非交通PM进行了比较。结果用于评估富集因子和初步来源分配。人为元素的富集因子为350。与非交通地点的样本相比，主要道路上基于硫元素指纹的交通来源几乎高出5倍。此外，还评估了PM排气和非排气排放（轮胎磨损，制动器磨损和道路灰尘重新悬浮）。结果发现，大部分粉尘是由轮胎磨损产生的，占33％，其次是道路粉尘的悬浮（31％），制动磨损（19％），然后是废气排放，占17％。废气中PM10排放的贡献较低是因为大多数注册车辆模型都是最近制造的，并配备了有效的废气PM减排技术。启示：本研究报告了与所有车辆的PM排放评估相关的第一个结果在卡塔尔注册的柴油重型车辆。对主要，小路以及非交通灰尘样品进行了原位XRF元素分析。实施了几种表征技术，结果表明，大部分粉尘是由轮胎磨损产生的，其次是路面粉尘重新悬浮，然后是刹车磨损。而自从大多数已注册的车型都已制造并配备了有效的PM减排技术以来，废气的排放量就大大减少了。