Identification of inhalable rutile and polycyclic aromatic hydrocarbons (PAHs) nanoparticles in the atmospheric dust

• Published in: Environmental pollution (1987) 2020-05, Vol.260, p.114006, Article 114006
• Main Authors: Gallego-Hernández, Ana L., Meza-Figueroa, Diana, Tanori, Judith, Acosta-Elías, Mónica, González-Grijalva, Belem, Maldonado-Escalante, Juan F., Rochín-Wong, Sarai, Soto-Puebla, Diego, Navarro-Espinoza, Sofia, Ochoa-Contreras, Roberto, Pedroza-Montero, Martín
• Format: Article
• Language: English
• Subjects: Arid areas; Atmospheric dust; PM1.0
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2020.114006

Addressing the presence of rutile nanoparticles (NPs) in the air is a work in progress, and the development of methodologies for the identification of NPs in atmospheric dust is essential for the assessment of its toxicological effects. To address this issue, we selected the fast growing desertic city of Hermosillo in northern Mexico. Road dust (n = 266) and soils (n = 10) were sampled and bulk Ti-contents were tested by portable X-ray fluorescence. NPs were extracted from atmospheric dust by PM1.0-PTFE filters and further characterized by Confocal Raman Microscopy, Energy-dispersive X-ray spectroscopy (EDS) coupled to Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Results showed (i) the average concentration of Ti in road dust (3447 mg kg−1) was similar to natural values and worldwide urban dusts; (ii) the bulk geochemistry was not satisfactory for Ti-NPs identification; (iii) 76% of the total extracted PM1.0 sample corresponded to NPs; (iv) mono-microaggregates of rutile NPs were identified; (v) ubiquitous polycyclic aromatic hydrocarbons (PAHs) were linked to NPs. The genotoxicity of rutile and PAHs, in connection with NPs content, make us aware of a crucial emerging environmental issue of significant health concern, justifying further research in this field. [Display omitted] •Synthetic rutile as NPs aggregates were identified in environmental samples.•Rutile NPs linked to PAHs were found in the airborne PM at pedestrian levels.•Ultrafine fraction of airborne dust showed particle size within the 41–60 nm range. Characterization of airborne NPs will help us identify the potential risks to human health and ecosystems.