Air pollution has emerged as the major environmental determinant affecting lung health. WHO estimated 7 million deaths worldwide with over 80 % of the urban population living in areas with AQI that exceed WHO limits (WHO, 2016). The increase in air pollution has shown a major impact on socioeconomic dimensions due to the migration of people in response to increased air pollution (Sanders, 2012). Chen et al. showed a 2.8 % reduction in population with every 10% increase in air pollution (Chen et al., 2017). Epidemiological studies have associated an increase in ambient particulate matter (PM) exposure with respiratory health concerns such as asthma, lung function decrements, lung cancer and COPD (Guo et al., 2019, Zhang et al., 2020, Zhao et al., 2018).

Diesel exhaust (DE) is the major contributor to air pollution due to its high PM concentration (Reşitoʇlu et al., 2015). DE contributes ∼28 % of the total PM in ambient air (Steiner et al., 2016). PM exposure is associated with decreased lung function and adverse pulmonary impact via inflammation and oxidative stress (Naidu et al., 2022, Wang et al., 2018). Moreover, recent studies have shown that diesel exposure in mice leads to pulmonary fibrosis which is regulated by epithelial to mesenchymal transition (Singh and Arora, 2022, Yue et al., 2023). Exposure to DE is mainly attributed to occupational hazards in coal miners and truck drivers (Lee et al., 2018, Lewis et al., 2016). About an 18 % increase in cancer risk was linked to heavy machine drivers/operators exposed to diesel exhaust (Tsoi and Tse, 2012). Further, the increasing incidence of pulmonary inflammation and injury observed in individuals residing in polluted cities suggest a critical role of DE in the development or exacerbation of pre-existing conditions (Rankin et al., 2021, Sawyer, 2008).

The harmful impact of DE on respiratory diseases has been explored by the researchers. (Faber et al., 2020, Liu et al., 2021); however, no clinical or in vivo studies have corroborated the reversibility or improvement in diesel exhaust induced lung injury after cessation of exposure. Understanding the degree of resolution of lung injury and the presence of diesel PM in lungs over a time period will bring significant insights into human health in relation to air pollution exposure. Therefore, in the present study, we explored the improvement/reversibility of diesel exhaust-induced lung damage after cessation of exposure. The findings of our study will provide new insight into the understanding of harmful effects of DE exposure and the perseverance of lung injury.