Exposure to high concentrations of fine particles (PM_2.5) with toxic metals can have significant health effects, especially during the Chinese spring festival (CSF), due to the large amount of fireworks’ emissions. Few studies have focused on the potential health impact of PM_2.5 pollution in small cities in China during the 2020 CSF, which coincided with the COVID-19 outbreak that posed a huge challenge to the environment and obvious health issues to countries around the world. We examined the characteristics of PM_2.5, including carbonaceous matter and elements, for three intervals during the 2020 CSF in Taizhou, identified the sources and evaluated the health risks, and compared them with those of 2018. The results showed that PM_2.5 increased by 13.20% during the 2020 CSF compared to those in the 2018 CSF, while carbonaceous matter (CM) and elements decreased by 39.41% and 53.84%, respectively. The synergistic effects of emissions, chemistry, and transport may lead to increased PM_2.5 pollution, while the lockdown measures contributed to the decrease in CM and elements during the 2020 CSF. Fe, Mn, and Cu were the most abundant elements in PM_2.5 in both years, and As and Cr(VI) should be of concern as their concentrations in both years exceeded the NAAQS guideline values. Industry, combustion, and mineral/road dust sources were identified by PCA in both years, with a 5.87% reduction in the contribution from industry in 2020 compared to 2018. The noncarcinogenic risk posed by As, Co, Mn, and Ti in 2018 and As and Mn in 2020 was significant. The carcinogenic risk posed by As, Cr(VI), and Pb exceeded the accepted precautionary limit (1 × 10⁻⁶) in both years. Mn was the dominant contributor to the total noncarcinogenic risks, while Cr(VI) showed the largest excessive cancer risks posed by metals in PM_2.5, implying its associated source, industry, was the greatest risk to people in Taizhou after exposure to PM_2.5. Despite the increase in PM_2.5 mass concentration, the health impacts were reduced by the lockdown policy implemented in Taizhou during the 2020 CSF compared to 2018. Our study highlights the urgent need to consider the mitigation of emissions in Taizhou and regional joint management efforts based on health protection objectives despite the rough source apportionment by PCA.

Based on the coupling coordination degree model and the exploratory spatial data analysis method, we established the coupling coordination relationship between urbanization and atmospheric environment and explored the spatial-temporal evolution characteristics of the coupling coordination degree of 11 provinces in the Yangtze River Economic Belt (YEB) from 2003 to 2017. The results indicated the following: (1) The level of urbanization increases linearly, and the atmospheric environment level shows a fluctuating upward trend. (2) The types of coordination gradually change from “Seriously uncoordinated development with urbanization lag” to “Superiorly coordinated development with atmospheric environment lag”. The spatial distribution of coordination shows the characteristics of “high in the eastern region and low in the central and western region”. Regarding temporal evolution, the coupling coordination degree of the region gradually increases, and the spatial differences between provinces gradually narrow. (3) Significant spatial autocorrelation is observed between the coordination of urbanization and atmospheric environment, which weakens over time. The local agglomeration mode shows that the “High-High” cluster areas are in the lower reaches and the “Low-Low” cluster areas are mainly in the middle or upper reaches. This study contributes to promoting the sustainable development of the Yangtze River Economic Belt and provides basic data and research perspectives for further investigation of the relationship between urbanization and atmospheric environment.