• Citer

MONITORING AND PREDICTING HEAVY METAL CONTENTS OF URBAN ROAD DUSTS: METHODOLOGY AND ANALYTICAL INSIGHTS IN SUPPORT OF GEOSPATIAL MODELS

par Dielie, Gwenaël ;Segato, Tiriana ;Schneider, Julien ;Madau, Patrizio ;Roevros, Nathalie ;Delplancke, Marie-Paule ;Verbanck, Michel
Référence EuroAnalysis 2025 (P3-022: 31 August - 4 September: Barcelona), EuroAnalysis 2025 - Abstract book, Vol. 1, page (677)
Publication Publié, 2025-09-03

Poster de conférence

• Détails
• Contenu

Résumé :

With the continued expansion of the global urban population, the monitoring of urban environments has become increasingly critical to public health. Road dust, composed of fine solid particles deposited on road surfaces, represents a key vector for airborne pollutants. The resuspension of these particles—particularly those in the finer fractions—can lead to elevated concentrations of heavy metals in the ambient air.In the municipality of Anderlecht (Brussels-Capital Region, Belgium), extensive street residue collection campaigns were conducted annually between April and September from 2019 to 2021. A standardized sampling protocol was employed, whereby a one-meter square stencil was used to delineate a rectangular surface area of 6 m² (2 m × 3 m), with the longer edge aligned along the interface between the roadway and the gutter. This area was exhaustively cleaned using an industrial-grade filtered vacuum system to recover both fine and coarse particulate matter. Thecollected material was subsequently subjected to granulometric processing (sieving) to isolate the <250 μm fractionfor further analysis.An initial compositional characterization was conducted using X-ray fluorescence (XRF) and X-ray diffraction (XRD) spectroscopy. XRF enabled the quantification of major and trace elements, including Pb, Zn, Cu, Cr, and Ni, in the <250 μm fraction. These preliminary results informed the design of analytical batches for subsequent elemental analysis using inductively coupled plasma optical emission spectrometry (ICP-OES). The known elemental composition of the analytical matrix was used to assess and mitigate spectral interferences.XRD analysis was employed to elucidate the mineralogical composition of the dust, facilitating the identification of crystalline phases and the association of metallic elements within specific compounds. This provided indirect insights into the presence of amorphous phases and the physicochemical states of the analytes. The particle size distribution of the fine dust was determined using laser diffraction, and the organic and volatile matter content was assessed via loss on ignition at 1000°C. A macroscopic examination of the samples was also performed to support qualitative observations.In terms of heavy metal analytical characterization per se, the study was structured in two main phases. The first phase focused on the development and comparative evaluation of three chemical extraction methods. The second phase encompassed the quantitative analysis of Pb, Zn, Cu, Cr, Ni, and Cd using ICP-OES. Cadmium was further analyzed by graphite furnace atomic absorption spectroscopy (Zeeman-GFAAS) to enhance sensitivity and accuracy. This relied on an alternative (fourth) extraction method.All analytical results were georeferenced using the Belgian Lambert 1972 coordinate system, enabling spatial representation within a Cartesian framework (datum: WGS84). The ultimate aim is to develop a valid geospatial model predicting heavy metal levels of dusts on each and every streets and roads of the Brussels-Capital Region.