Surdacki, M. et al. 2026. Changes in emergency department visit volume before, during and after the COVID-19 pandemic, with an exploratory assessment of air pollution: a preliminary ecological study from Poznań, Poland. Polish Journal of Public Health. 136, (Jun. 2026), 55–59. DOI:https://doi.org/10.12923/2083-4829/2026-0010.