Characterizing the elemental enrichment patterns of fractionated road dust and fluxes in the environment

表征环境中分馏道路灰尘和通量的元素富集模式

• 批准号: RGPIN-2018-05966
• 负责人: Wiseman, Clare
• 金额: $ 1.82万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=713970
• 关键词: Characterizing; elemental; enrichment; patterns; fractionated

Road dust is a sink for a range of metals and metalloids emitted from traffic-related activity in both exhaust (tailpipe) and non-exhaust (wear of street surfaces, automotive components, etc. and their resuspension) forms. As a pollutant sink, road dust is a likely major contributor to local air, water and soil contamination. The evidence to date suggests the finer particle size fractions of road dust have a high potential to be mobilized via resuspension processes and impact local air quality. While the chemical composition of road dust in particle size fractions >63 microns has been well-characterized in a number of studies, there are large data gaps on the following: 1. total traffic-associated particle and metal loadings to roads, 2. elemental enrichment patterns as a function of particle size fraction and associated potential to be mobilized via resuspension processes and, 3. the contribution of specific automotive and street wear sources to road dust particle size fractions capable of being inhaled. This hinders an estimation of road dust-associated elemental fluxes in an urban context and the identification of source emissions as a function of particle size contribution and potential toxicity for management and abatement purposes. In particular, data is lacking regarding the concentrations and road dust enrichment patterns of emerging metals of concern such as rare earths and platinum group elements. The proposed research will systematically examine the particle size mass distribution and associated metal and metalloid enrichment of road dust collected from a variety of roads with different traffic volumes, fleet composition, etc., in the Greater Toronto Area. The particle size distribution of total road dust samples will be examined to estimate the mass contribution of fine fractions of human and environmental health concern to total amounts deposited on roads of various types. Metal and metalloid concentrations will be determined for unfractionated and fractionated road dust samples for the calculation of elemental loading to streets and flux estimates. The data serve as a basis for development of a model to assess the extent to which mobile fractions of road dust may contribute to urban air pollution and contamination on a wider spatial scale.

道路灰尘是交通相关活动中以排气（排气管）和非排气（街道表面、汽车部件等的磨损及其再悬浮）形式排放的一系列金属和类金属的汇。作为污染物汇，道路灰尘可能是当地空气、水和土壤污染的主要原因。迄今为止的证据表明，道路灰尘的更细粒度部分很可能通过再悬浮过程被动员起来，并影响当地的空气质量。虽然许多研究已经很好地描述了 >63 微米颗粒尺寸部分的道路灰尘的化学成分，但在以下方面仍存在很大的数据差距：1. 道路上与交通相关的颗粒和金属负载总量，2. 元素富集模式作为颗粒尺寸部分的函数以及通过再悬浮过程调动的相关潜力，3. 特定汽车和街道磨损源对道路灰尘颗粒尺寸部分的贡献 被吸入。这阻碍了对城市环境中道路灰尘相关元素通量的估计，也阻碍了将源排放识别为颗粒大小贡献和潜在毒性的函数，以达到管理和减排的目的。特别是，缺乏有关稀土和铂族元素等新兴金属的浓度和道路灰尘富集模式的数据。 拟议的研究将系统地研究从大多伦多地区不同交通量、车队组成等的各种道路收集的道路灰尘的粒径质量分布以及相关金属和非金属富集度。将检查总道路灰尘样本的粒径分布，以估计人类和环境健康问题的细小部分对沉积在各种类型道路上的总量的质量贡献。将测定未分级和分级道路灰尘样品的金属和类金属浓度，以计算街道的元素负荷和通量估计。这些数据可作为开发模型的基础，以评估道路灰尘的移动部分对城市空气污染和更广泛空间范围内的污染的影响程度。