Influence of Temporal Resolution on the Characterization of Episodic Air Pollution Events: Experimental Evidence from New Year’s Eve Fireworks

Episodic air pollution events (EAPEs) remain significantly less investigated than pollution generated by continuous emission sources, despite their potential to produce intense short-term concentration peaks and acute exposure conditions. Among these events, fireworks displays represent one of the most intense and short-lived anthropogenic sources of atmospheric pollution in urban environments. The research presents and discusses the use of reference air quality monitoring approaches to characterize transient pollution episodes, highlighting the limitations of conventional monitoring systems and regulatory frameworks, which rely on hourly or daily averaged concentrations and may therefore underestimate the real temporal evolution, peak intensity, and short-term exposure associated with EAPEs. Experimental field investigations were conducted over two consecutive years during New Year’s Eve celebrations, using an integrated monitoring approach combining certified reference instrumentation and calibrated low-cost sensors. PM10, NO2, CO, and O3 concentrations were monitored before, during, and after the events, enabling comparisons between daily, hourly, and minute-resolution measurements. Results demonstrated that conventional monitoring successfully identifies the occurrence of the pollution episode but fails to adequately characterize its peak dynamics. Minute-resolution PM10 measurements revealed concentrations up to 215 µg m−3, approximately three times higher than the corresponding hourly values (Peak Amplification Factor, PAF = 2.90–2.93), while transient variations in gaseous pollutants were consistently identified. The findings provide experimental evidence supporting the integration of high-temporal-resolution measurements with conventional monitoring networks to improve the characterization of episodic air pollution events, thereby supporting environmental authorities in enhancing monitoring strategies, exposure assessment, air quality management, and the protection of public health.