Utilization of road dust chemical profiles for source identification and human health impact assessment

Abstract

This study investigated the chemical profiles of fine urban road dust as a set of indicators for major air pollutants at sampling sites or as proxies for potential human health impacts. We examined the chemical compositions of fine particles (< 100 μm) or re-suspended ultrafine particles (< 2.5 μm) in the urban road dust collected from the cities with major emission sources of CO, NH 3 , NO x , PM 2.5 , SO x , and volatile organic compounds. The elemental compositions, including metal contents and volatile or semi-volatile organic compound species were determined to constitute comprehensive chemical profiles of the solid road dust samples. The water-extractable organic compounds and fluorescent species of the size-fractionated re-suspended fine particulate matter (RPM) were also incorporated in the chemical profiles. The metal content and aliphatic hydrocarbons could partly distinguish emission sources, and clearer distinctions were achieved with the inclusion of fluorescence excitationemission matrix (EEM) results. The dose-response test results showed positive correlations between cytotoxicity and relative abundance of hydrocarbons or metal contents of urban road dust. The set of chemical profiles suggested in this study could be further utilized for site identification or human health impact assessment using urban road dust. Chemical profiles of urban road dust can be utilized not only for assessing health risks but also for identifying the sources of the dust which accumulates chemical ingredients originated from the local environment in close vicinity. The air pollutants may influence the chemical compositions of dust in multiple ways. Both adsorption of air pollutant to fine dust particles and absorption of ambient particulate matter such as PM 10 to road dust could contribute to partitioning 1 of air pollutants to road dust. Deposition of ambient particulate matter on road dust could be another pathway that air pollutants influence the chemical compositions of road dust. Wang et al. 2 investigated factors associated with adsorption of polycyclic aromatic hydrocarbons on road dust. Absorption or deposition of aggregated PM 10 on road dust may also add air pollutants to road dust particles because a great portion of PM 10 results from main gaseous precursors 3,4 , such as CO, SO x , NO x , NH 3 , and VOCs in the atmosphere. These series of findings support the hypothesis of this study that fine road dust can store information about the major emission sources in vicinity. The fact that chemical composition of road dust is related to a footprint of the local chemical environment forms the basis of environmental soil forensics 5. The large surface areas of the fine particle fractions in urban road dust could store rich information about the surrounding chemical environment. The elemental composition 6-8 of urban road dust contains information about its origin, such as the earth's crust (Mg, Al, Si, Ca, and Fe) 9. Trace elemental analysis of fine road dust particles could reveal anthropogenic sources, such as tr...

Insight into PM&lt;sub&gt;2.5&lt;/sub&gt; Sources by Applying Positive Matrix Factorization (PMF) at an Urban and Rural Site of Beijing

“…Road dust. This factor makes a major contribution to crustal species, such as Na + , Al and Fe (60%, 48% and 34% of species in this factor respectively) suggesting this factor may represent the characteristics of a dust related source as reported previously (Kim and Koh, 2020). In addition, the given factor also included significant contributions to Mn, Pb and Zn (26%, 23% and 20% of species in this factor respectively), which are associated with brake and tyre wear as mentioned above (Pant and Harrison, 2012;Pant and Harrison, 2013;Grigoratos and Martini, 2015;Piscitello et al, 2021).…”

A Review of Road Traffic-Derived Non-Exhaust Particles: Emissions, Physicochemical Characteristics, Health Risks, and Mitigation Measures

“…As many of these components are highly correlated within the panels of PM tested, this method has inherent limitations. However, several studies augmented this observational approach through inhibition of component-specific biological pathways (metal handling, , aryl hydrocarbon receptor mediated xenobiotic metabolism, toll-receptor mediated responses to PM associated biological components or PM fractionation).…”

Induction of toxicity in human colon cells and organoids by size- and composition-dependent road dust

“…Elemental compositions of road dust were analysed (Table S1 †). Previous studies 25,26 have shown that road dust contains various chemical compounds, including organic carbons, sulfur compounds, metals and ions. These studies showed that metal compositions and the relative abundance of hydrocarbons have positive correlations with cytotoxicity and that the chemical prole of road dust may be used as a proxy for assessing human health impacts.…”