AsseSsing the Pulmonary Hazards and molecular mechanIsms of Nanoplastics from TyRe Wear Emissions

Airborne tyre wear nanoplastics (TW-NPLs) are emerging environmental contaminants generated by tyreroad abrasion and increasingly recognised as a threat to public health. As a major component of urban particulate pollution, they are continuously inhaled by millions of people, yet their pulmonary effects, mechanisms of action, and long-term risks remain largely unknown. This knowledge gap is particularly concerning given that TW-NPLs combine nanoscale size, allowing deep lung penetration, with a high load of toxic chemical additives. Understanding their biological behaviourand how it is influenced by particle physicochemical propertiesis therefore essential to support preventive public health measures and inform the development of tyre materials with reduced emission potential. Because epidemiological studies cannot isolate the specific contribution of TW-NPLs from co-exposure to other exhaust and non-exhaust pollutants, advanced in vitro approaches represent the most appropriate strategy to establish the mechanistic and causal evidence needed. Within this framework, ASPHIRE will apply two physiologically relevant pulmonary New Approach Methodologies (NAMs) that support long-term inhalation exposure, thereby reproducing chronic exposure scenarios. These systems will be used to identify the cellular, molecular, and pathway-level alterations induced by sustained TW-NPL exposure through a multi-level mechanistic strategy that integrates validated toxicity biomarkers with multi-omics readouts. By elucidating the causal molecular basis of TW-NPL-induced toxicity, the project will provide the scientific foundation necessary to inform safer tyre design, support emission-reduction policies, and strengthen evidence-based regulatory action aimed at protecting human health. Impacto científico técnico o internacional esperable: Tyre wear nanoplastics (TW-NPLs) constitute a growing yet poorly regulated source of inhalable particulate pollution, increasingly recognised for their potential respiratory risks. Advancing their risk assessment is essential, but major gaps persist, including the scarcity of environmentally realistic reference materials, the limited availability of long-term toxicity data, and an insufficient mechanistic and causal understanding of their biological effects. ASPHIRE is designed to address these gaps. The project will deliver comprehensive information on TW-NPL-induced pulmonary toxicity, with particular attention to long-term effects. Using advanced in vitro approaches that reproduce human physiology and allow chronic exposure scenarios, ASPHIRE will identify cellular, molecular, and pathway-level alterations triggered by sustained TW-NPL exposure. This mechanistic strategy will integrate validated effect biomarkers with multi-omics analyses. The resulting datasets will reveal molecular and cellular signatures relevant for evaluating nanoplastic- induced pulmonary toxicity. These key data will be systematically integrated with in-house and external knowledge within an Adverse Outcome Pathway (AOP) framework, maximising their utility for regulatory applications and future risk assessment. The project will also inform mitigation strategies, contribute to the development of emission-reduction measures, and promote public awareness and behavioural change toward more sustainable mobility practices, including eco-designed tyres and driving habits that reduce abrasion. Therefore, the project is expected to generate substantial social impact. As public awareness of plastic pollution grows, recognising TW-NPLs as an airborne source directly affecting human health is crucial for encouraging behavioural change and supporting policy uptake. At the policy level, tyre abrasion rate, defined under UNECE R117 and aligned with Euro 7, is now considered the most effective regulatory lever to reduce particulate emissions. Even modest reductions (1030%) could yield substantial health and economic benefits within the next decade. Conservative estimates indicate that a 10% reduction in average tyre abrasion could generate 7.414 billion in net savings across Europe between 2025 and 2050 highlighting that improving emission monitoring and control represents a health, environmental, and economic priority.