Foreign research progress on social impact and emergency management in the post-pandemic era

We define the concept and analyze the connotation of the post-pandemic era by reviewing the recent foreign research on social impacts, risk prevention and control, and emergency management in the post-pandemic era. The current state of foreign research in the post-pandemic era is outlined, and the progress of foreign research on social impacts like urban planning and travel patterns, as well as core issues like risk prevention and control and emergency management in the post-pandemic era is analyzed in detail. The characteristics and shortcomings of existing research are summarized and future research in the postpandemic era is also forecasted. COVID-19 has had a huge impact on how people socialize, travel, and work, as well as changing industry trends, technical advancements, and social governance. Uncertainty is the most significant risk feature of the post-pandemic era, and the coupling of numerous hazards poses a new set of challenges to emergency management practices.

Drivers of High Concentrations of Secondary Organic Aerosols in Northern China during the COVID-19 Lockdowns.

During the COVID-19 lockdown in early 2020, observations in Beijing indicate that secondary organic aerosol (SOA) concentrations increased despite substantial emission reduction, but the reasons are not fully explained. Here, we integrate the two-dimensional volatility basis set into a state-of-the-art chemical transport model, which unprecedentedly reproduces organic aerosol (OA) components resolved by the positive matrix factorization based on aerosol mass spectrometer observations. The model shows that, for Beijing, the emission reduction during the lockdown lowered primary organic aerosol (POA)/SOA concentrations by 50%/18%, while deteriorated meteorological conditions increased them by 30%/119%, resulting in a net decrease in the POA concentration and a net increase in the SOA concentration. Emission reduction and meteorological changes both led to an increased OH concentration, which accounts for their distinct effects on POA and SOA. SOA from anthropogenic volatile organic compounds and organics with lower volatility contributed 28 and 62%, respectively, to the net SOA increase. Different from Beijing, the SOA concentration decreased in southern Hebei during the lockdown because of more favorable meteorology. Our findings confirm the effectiveness of organic emission reductions and meanwhile reveal the challenge in controlling SOA pollution that calls for large organic precursor emission reductions to rival the adverse impact of OH increase.