Parma, 22 September 2026 – Ants can act as “biological sensors” of urban pollution. This is demonstrated by a University of Parma study recently published in the international journal Environmental Pollution, which proposes a new approach to detecting and mapping magnetic particulate matter associated with road traffic. The study opens up practical prospects for widespread, scalable and low-cost biomonitoring systems that complement conventional monitoring methods.
The study (Ants as bioindicators of urban traffic pollution) used the tree-dwelling ant Crematogaster scutellaris as a sentinel organism. Sampling covered 30 sites across the city of Parma with varying traffic levels, as well as four control areas with no vehicle traffic. Official traffic flow data collected by Parma City Council in different parts of the city were analysed in relation to the particles accumulated on the ants’ bodies and those found in the soil.
By combining magnetic susceptibility measurements with scanning electron microscopy, the researchers observed a strong association between traffic intensity and the amount of magnetic particulate matter on the ants; the same relationship was not found in the soil samples. In the model developed, every additional 1,000 vehicles per day corresponded to a 1.41-fold increase (approximately 41%) in the ants’ magnetic susceptibility. The particles, concentrated mainly on the thorax, were rich in iron oxides and also contained zinc, copper and titanium, with sizes and shapes consistent with traffic-derived particulate matter.
Multidisciplinary collaboration was central to the work. Within the Department of Chemistry, Life Sciences and Environmental Sustainability (SCVSA), Daniele Giannetti, Antonio Verolino, Enrico Schifani (now a postdoctoral researcher at Pompeu Fabra University in Barcelona), Luciana Mantovani and Donato A. Grasso worked together, combining expertise in biology, ethology, ecology, mineralogy and environmental analysis. This collaboration also involved Francesco Cugini, Daniele Pontiroli and Massimo Solzi from the Department of Mathematical, Physical and Computer Sciences, who contributed their expertise in magnetic characterisation.
“The most interesting finding is that ants do more than simply record the presence of particles: thanks to their nest fidelity, foraging activity and direct contact with the environment, they provide a local signature of exposure integrated over time,” explains Donato A. Grasso, the study’s scientific coordinator. “This is a very concrete example of how biology, ecology, mineralogy and materials physics can come together to develop new tools for understanding the environment. Ants do not replace monitoring stations, but they can serve as a highly sensitive biological matrix, helping to identify problem areas at a much finer spatial resolution, where instrumental measurements and interventions can then be focused.”
The practical potential lies in developing a two-tier approach to environmental assessment: rapid, relatively inexpensive screening based on magnetic susceptibility, followed by particle characterisation at selected sites. Such a protocol could support high-resolution urban mapping, identify deposition hotspots and guide targeted air quality monitoring campaigns.
The next steps will involve validating the method across different seasons, cities and environmental settings, comparing it with data from official monitoring networks and other bioindicators, and investigating the potential effects of particulate matter on colony health. Future integration with meteorological data, digital mapping and automated analytical procedures could lay the foundations for a widespread network for biological monitoring of pollution.
Link to the paper
Reference: Giannetti, D., Verolino, A., Mantovani, L., Cugini, F., Schifani, E., Pontiroli, D., Solzi, M., Grasso, D.A. (2026). Ants as bioindicators of urban traffic pollution. Environmental Pollution, 409, 129010.
