Innovative multidisciplinary biomonitoring studies on the environmental impact of microplastics from tire wear are underway in Toronto.
An international team of experts from theUniversity of Siena (UniSI), ofNational Institute of Geophysics and Volcanology (INGV) and Trent University in Peterborough, Canada, studied the spread of non-exhaust (abrasive, unburned) automotive emissions along a 150-meter transect of Highway 401 in Toronto, Ontario, the busiest road in North America.
The study, entitled: “Distance decay of tire wear particles and potentially toxic elements near Canada's busiest highway: Assessing lichen transplants as biomonitors”, was carried out by exposing lichen transplants at different distances from the road surface, thus highlighting, through multidisciplinary analyses, the exponential decrease in the bioaccumulation of microplastics from tire wear with increasing distance from the road and the concomitant 70% reduction in vehicular metal particulate content within 35 metres of the road highway, with a robust correlation between particulate matter emitted by brakes and tyres.
The research was carried out as part of the joint PhD between UniSi and INGV, in collaboration with the CHIOMA project (Cultural Heritage Investigations and Observations: a Multidisciplinary Approach)”.
“During my stay abroad for my doctoral studies”, declares Lisa Grifoni, recent PhD cum laude in Life Sciences, “Innovative combined optical, chemical and magnetic analyses were undertaken in collaboration with Prof. Julian Aherne of the School of Environment at Trent University, for outline the spread of the microplastics from tire wear in urban environments characterized by intense vehicular traffic, obtaining excellent indications on the potential of these integrated methods".
“The new Euro 7 provisions represent a turning point in automotive emissions legislation, regulating for the first time the emission limits from friction, i.e. from brakes and tyres", He declares Aldo Winkler, head of the paleomagnetism laboratory of the INGV, “In this sense, this article introduces the application of magnetic methodologies to tire microplastics, expanding on the approach that in 2020 demonstrated the crucial role of automotive brakes in the spread of metallic particulate matter in urban areas.”
“This study opens new perspectives in the use of lichens as bioaccumulators polluting particulate matter, highlighting the close correlation between micro-rubber, potentially toxic chemical elements and magnetic particulate matter, through exhibition designs that allow us to observe the spread of automotive emissions with a spatial resolution that is difficult to achieve with other methods.", points out Stefano Loppi, professor at the Department of Life Sciences at UniSi.
Future developments, continuing the CHIOMA project, include investigating the spread and contamination of cultural heritage by microplastics, using magnetic and chemical biomonitoring methods for their preventive conservation.
Link to the study:
https://doi.org/10.1016/j.envres.2026.124221
Links
Istituto Nazionale di Geofisica e Vulcanologia
Trent University, Peterborough
Photo - a. Survey site, near Highway 401. b. Exposed lichen transplant