Background: Atmospheric pollution is widely recognised as a determinant of respiratory and cardiovascular morbidity; however, its contribution to psychiatric burden remains underappreciated in both clinical and regulatory contexts. This asymmetry in recognition risks may underestimate the mental health toll of environmental hazard exposure. Purpose: This commentary synthesises the available evidence linking ambient air pollutant exposure primarily particulate matter (PM₂.₅, PM₁₀) and nitrogen oxides to psychiatric outcomes including depression, anxiety, psychological stress, and suicidal behaviour, and examines the implications for clinical practice and environmental policy. Evidence summary: Reviewed studies spanning longitudinal cohorts, quasi-experimental designs, systematic reviews, and predictive modelling consistently demonstrate associations between air pollution and psychiatric symptomatology across diverse populations. A non-linear dose-response pattern is observed, with mental health risks emerging at pollutant concentrations within or below established regulatory thresholds. Stress response to inhaled pollutants with neuroendocrine activation including hypothalamus-pituitary-adrenal axis and sympathetic-adrenal-medullary stimulation offer a plausible mechanistic basis. Decontamination interventions have shown prospective benefits on depressive burden. Conclusions: The mental health burden associated with ambient air pollution could be underestimated by current diagnostic frameworks and may not be adequately prevented by existing air quality standards. Clinicians should consider environmental exposures in the differential assessment of psychiatric symptoms, and policymakers are urged to revise regulatory thresholds to reflect the non-linear risk profiles identified for vulnerable populations.
Dr. Ana Rodriguez (Thu,) studied this question.