Finding needles in a haystack: measuring ambient concentrations of naturally occurring elongated mineral particles in an urban environment. in Chemosphere / Chemosphere. 2026 May;401:144916. doi: 10.1016/j.chemosphere.2026.144916. Epub 2026 Mar 31. (2026)

Tipo pubblicazione

Journal Article

Autori/Collaboratori (14)
Elenco ridotto

  • Elangasinghe ASchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand; Mote Limited, 40a George Street, Mount Eden, Auckland, New Zealand. Electronic address: anushka.elangasinghe@auckland.ac.nz.
  • Patel HSchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand; Mote Limited, 240 Queen Street, Brisbane, QLD, 4000, Australia; International Laboratory for Air Quality & Health (ILAQH), Queensland University of Technology, 2 George Street, Brisbane, Queensland, 4000, Australia.
  • Dirks KNDepartment of Civil and Environment Engineering, Faculty of Engineering, University of Auckland, Auckland, New Zealand.
  • Fan WWSchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.
  • de Zoysa ASchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.
  • Yi CZSchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.
  • Young PGSchool of Biological Sciences, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.
  • Hamilton ASchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.
  • Talbot NEnvironment Southland, Cnr North Rd &, Price Street, Waikiwi, Invercargill, New Zealand.
  • Brook MSchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.
  • Wells BMote Limited, 40a George Street, Mount Eden, Auckland, New Zealand.
  • Williams DEMote Limited, 40a George Street, Mount Eden, Auckland, New Zealand; School of Chemical Sciences, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.
  • Davy PNew Zealand Institute for Earth Science Limited, Wellington, New Zealand.
  • Salmond JASchool of Environment, Faculty of Science, University of Auckland, Private Bag, 92019, Auckland, New Zealand.

Abstract

Naturally occurring elongated mineral particles (EMPs) are microscopic particles derived from rocks and soils and are defined by their high aspect ratios. They include both asbestiform minerals, some of which are recognised carcinogens, and non-asbestiform minerals. While occupational exposure to commercially used EMPs such as asbestos has been extensively studied, population-scale exposure to naturally occurring EMPs in environmental settings remains poorly understood. Direct measurements of ambient EMP concentrations are rare due to their low abundance and the analytical difficulty of isolating fibres from complex ambient particulate matter. To address these challenges, a cost-effective, filter-based air-sampling network was established in Riverhead, Auckland, New Zealand, where erionite and other elongated mineral particles have been reported in local geology. A multi-tiered analytical workflow was applied, combining automated scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) for high-throughput screening with transmission electron microscopy and selected-area electron diffraction (TEM-SAED) for mineralogical confirmation. Automated SEM-EDS screening identified 449 EMPs across the sampled locations, of which 29 exhibited Si:Al ratios within the range characteristic of erionite. However, subsequent TEM-SAED analysis confirmed that none of these particles were erionite. These results indicate that airborne erionite was not detected in the analysed filters within the spatial and temporal scope and analytical detection limits of the monitoring campaign. The study demonstrates the utility of combining dense monitoring networks with automated SEM-based screening as a scalable framework for environmental EMP surveillance in regions where fibrous minerals occur in local geology.

PMID: 41923682

Keywords

Environmental Monitoring/methods; Minerals/analysis; Air Pollutants/analysis; New Zealand; Particulate Matter/analysis; Cities; Microscopy, Electron, Scanning; Particle Size; Spectrometry, X-Ray Emission; Microscopy, Electron, Transmission; Zeolites/analysis;