BackgroundThe elevation and dissipation of pollutants after the ignition of fireworks in different functional areas of a valley city were investigated.MethodsThe Air Quality Index (AQI) as well as inter-day and intra-day concentrations of various air pollutants (PM10, PM2.5, SO2, NO2, CO, O3) were measured during two episodes that took place during Chinese New Year festivities.ResultsFor the special terrain of Jinan, the mean concentrations of pollutants increased sharply within 2–4 h of the firework displays, and concentrations were 4–6 times higher than the usual levels. It took 2–3 d for the pollutants to dissipate to background levels. Compared to Preliminary Eve (more fireworks are ignited on New Year’s Eve, but the amounts of other human activities are also lesser), the primary pollutants PM2.5, PM10, and CO reached higher concentrations on New Year’s Eve, and the highest concentrations of these pollutants were detected in living quarters. All areas suffered from serious pollution problems on New Year’s Eve (rural = urban for PM10, but rural > urban for PM2.5). However, SO2 and NO2 levels were 20%–60% lower in living quarters and industrial areas compared to the levels in these same areas on Preliminary Eve. In contrast to the other pollutants, O3 concentrations fell instead of rising with the firework displays.ConclusionInteractions between firework displays and other human activities caused different change trends of pollutants. PM2.5 and PM10 were the main pollutants, and the rural living quarter had some of the highest pollution levels.

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The objective of this study was to explore the impact of maternal AT during pregnancy on childhood asthma and wheezing, as well as the potential effect modifiers in this association. A cross-sectional study was implemented from December 2018 to March 2019 in Jinan to investigate the prevalence of childhood asthma and wheezing among aged 18 months to 3 years. Then, we conducted a case-control study based on population to explore the association between prenatal different AT exposure levels and childhood asthma and wheezing. The association was assessed by generalized additive model and logistic regression model, and stratified analyses were performed to explore potential effect modifiers. A total of 12,384 vaccinated children participated in screening for asthma and wheezing, and 236 cases were screened, as well as 1445 controls were randomized. After adjusting for the covariates, childhood asthma and wheezing was significantly associated with cold exposure in the first trimester, with OR 1.750 (95% CI: 1.145–2.673), and cold exposure and heat exposure in the third trimester, with ORs 1.583 (95% CI: 1.013–2.474) and 2.124 (95% CI: 1.415–3.188). In the third trimester, enhanced impacts were found among girls, children whose distance of residence was close to the nearest main traffic road, children whose mothers never had vitamin D supplementation, and children whose parents have asthma. The study indicates that exposure to extreme AT during the first trimester and the third trimester could increase the risk of childhood asthma and wheezing.