Does Lockdown Improve Air Quality? Evidence from the blockade policy of county-level units in Hubei Province, China (preprint)

Background: The COVID-19 posed a great threat to the health of people all over the world. In response to the outbreak of COVID-19, Wuhan implemented the blockade policy on January 23, 2020. Subsequently, other cities in Hubei responded one after another. The flow of people, production and consumption activities were greatly reduced, and air pollution in some cities was obviously improved. Method We used the daily air pollution and weather data of 103 county-level units in Hubei Province from 2019 to 2020 to test whether the blockade policy affected the air quality. The method of regression discontinuity designs is adopted. And the blockade policy implemented by the government during COVID-19 is regarded as exogenous policy impact, so as to investigate whether the blockade policy will affect the air quality. Results (1) Lockdown has indeed brought about an improvement in air quality. During the lockdown period, the AQI decreased by 15.316%, and the concentrations of four air pollutants (PM10, NO2, PM2.5 and SO2) decreased by 19.607%, 12.395%, 11.448% and 1.278% respectively. (2) The improvement of air quality brought about by the blockade policy is not sustainable, and every index rebounded again about 30 days after lockdown. (3) RD estimation found that the concentrations of AQI, PM2.5, PM10 and NO2 decreased by 35.402%, 29.207%, 14.809% and 7.751% respectively. This is consistent with the change trend of the above results, but the change range is obviously larger than the previous one. Conclusion Although the study confirmed that most pollutant indexes decreased during the lockdown period, the blockade policy is not applicable to the prevention and improvement of air pollution. We put forward the policy suggestions from the following two aspects: Firstly, promote green travel and reduce traffic emission sources. Secondly, promote end-of-pipe governance and improve emission reduction efficiency.

Modelling the effect of local and regional emissions on PM2.5 concentrations in Wuhan, China during the COVID-19 lockdown

PM2.5 concentrations in Wuhan, China decreased by 36.0% between the period prior to the COVID-19 pandemic (1‒23 January, 2020) and the COVID-lockdown period (24 January to 29 February, 2020). However, decreases in PM2.5 concentration due to regional PM2.5 transport driven by meteorological changes, and the relationship between the PM2.5 source and receptor, are poorly understood. Therefore, this study assessed how changes in meteorology, local emissions, and regional transport from external source emissions contributed to the decrease in Wuhan’s PM2.5 concentration, using FLEXPART-WRF and WRF-Chem modelling experiments. The results showed that meteorological changes in central China explain up to 22.2% of the total decrease in PM2.5 concentrations in Wuhan, while the remaining 77.8% was due to air pollutant emissions reduction. Reduction in air pollutant emissions depended on both local and external sources, which contributed alomst equally to the reduction in PM2.5 concentrations (38.7% and 39.1% of the total reduction, respectively). The key emissions source areas affecting PM2.5 in Wuhan during the COVID-lockdown were identified by the FLEXPART-WRF modeling, revealing that regional-joint control measures in key areas accounted for 89.3% of the decrease in PM2.5 concentrations in Wuhan. The results show that regional-joint control can be enhanced by identifying key areas of emissions reduction from the source‒receptor relationship of regional PM2.5 transport driven by meteorology under the background of East Asian monsoon climate change.

Clinical course and management of 73 hospitalized moderate patients with COVID-19 outside Wuhan (preprint)

Background: Moderate cases account for the majority in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and can also progress to severe/critical condition. Here, we investigated the clinical course and management of hospitalized moderate SARS-CoV-2 patients.Methods: The medical records and follow-up data were analyzed from the SARS-CoV-2 patients outside Wuhan.Results: A total of 73 moderate patients (38 men, 35 women) were included, with median age of 47.0 (38.5-57.5) years. Among them, only one patient (1.4%) died using active treatment to improve symptoms. The median duration of the four main symptoms cough, fever, chest tightness, and fatigue were about 1-2 weeks; the median duration of the positive nucleic acid test (NAT) results for SARS-CoV-2 was slightly more than 2 weeks; the median hospitalization time was almost four weeks in 72 moderate survivors. The duration of cough and fever was positively correlated with the duration of the positive NAT results. On admission, 50% had lymphopenia; less than 30% had abnormal blood biochemistry findings involving hyperglycemia, liver function and myocardial enzymes. At discharge, the laboratory indexes were substantially improved. Two weeks after discharge, 5.6% survivors experienced a recurrence of the positive NAT results. Conclusions: Moderate SARS-CoV-2 patients have a good prognosis by the active treatment. After discharge, it is necessary that moderate survivors undergo at least a 2-week collective medical observation in quarantine places, which can identify and treat a proportion of patients with re-positive NAT results and to prevent the spread of the potential sources of infection.

Clinical Course and Management of 73 Hospitalized Moderate Patients with COVID-19 Outside Wuhan (preprint)

Background: Moderate cases account for the majority in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and can also progress to severe/critical condition. Here, we investigated the clinical course and management of hospitalized moderate SARS-CoV-2 patients.Methods: The medical records and follow-up data were analyzed from the SARS-CoV-2 patients outside Wuhan.Results: A total of 73 moderate patients (38 men, 35 women) were included, with median age of 47.0 (38.5-57.5) years. Among them, only one patient (1.4%) died using active treatment to improve symptoms. The median duration of the four main symptoms cough, fever, chest tightness, and fatigue were about 1-2 weeks; the median duration of the positive nucleic acid test (NAT) results for SARS-CoV-2 was slightly more than 2 weeks; the median hospitalization time was almost four weeks in 72 moderate survivors. The duration of cough and fever was positively correlated with the duration of the positive NAT results. On admission, 50% had lymphopenia; less than 30% had abnormal blood biochemistry findings involving hyperglycemia, liver function and myocardial enzymes. At discharge, the laboratory indexes were substantially improved. Two weeks after discharge, 5.6% survivors experienced a recurrence of the positive NAT results. Conclusions: Moderate SARS-CoV-2 patients have a good prognosis by the active treatment. After discharge, it is necessary that moderate survivors undergo at least a 2-week collective medical observation in quarantine places, which can identify and treat a proportion of patients with re-positive NAT results and to prevent the spread of the potential sources of infection.

The psychological impact of COVID-19 outbreak on medical staff and the general public (preprint)

Purpose: To assess the psychological effects of the novel coronavirus disease (COVID-19) on medical staff and the general public.Methods: During the outbreak of COVID-19, an internet-based questionnaire included The Self-rating Depression Scale (SDS), Perceived Stress Scale (PSS-10), and Impact of Event Scale-Revised (IES-R) was used to assess the impact of the epidemic situation on the mental health of medical staff and general population in Wuhan and its surrounding areas.Results: The results suggest that the outbreak of COVID-19 has affected individuals significantly, the degree of which is related to age, sex, occupation and mental illness. There was a significant difference in PSS-10 and IES-R scores between the medical staff and the general population. The medical staff showed higher PSS-10 scores (16.813 ± 4.87) and IES-R scores (22.40 ± 12.12) compared to members of the general population PSS-10 (14.80 ± 5.60) and IES-R scores (17.89 ± 13.08). However, there was no statistically significant difference between the SDS scores of medical staff (44.52 ± 12.36) and the general public (43.08 ± 11.42). In terms of the need for psychological assistance, 50.97% of interviewees responded that they needed psychological counseling, of which medical staff accounted for 65.87% and non-medical staff accounted for 45.10%.Conclusion: During the ongoing COVID-19 outbreak, great attention should be paid to the mental health of the population, especially medical staff, and measures such as psychological intervention should be actively carried out for reducing the psychosocial effects.

Detectable serum SARS-CoV-2 viral load (RNAaemia) is closely associated with drastically elevated interleukin 6 (IL-6) level in critically ill COVID-19 patients (preprint)

Background: Although the SARS-CoV-2 viral load detection of respiratory specimen has been widely used for novel coronavirus disease (COVID-19) diagnosis, it is undeniable that serum SARS-CoV-2 nucleic acid (RNAaemia) could be detected in a fraction of the COVID-19 patients. However, it is not clear that if the incidence of RNAaemia could be correlated with the occurrence of cytokine storm or with the specific class of patients. Methods: This study enrolled 48 patients with COVID-19 admitted to the General Hospital of Central Theater Command, PLA, a designated hospital in Wuhan, China. The patients were divided into three groups according to the Diagnosis and Treatment of New Coronavirus Pneumonia (version 6) published by the National Health Commission of China. The clinical and laboratory data were collected. The serum viral load detection and serum IL-6 levels were determined. Except for routine statistical analysis, Generalized Linear Models (GLMs) analysis was used to establish a patient status prediction model based on real-time RT-PCR Ct value. Findings: The Result showed that cases with RNAaemia were exclusively confirmed in critically ill patients group and appeared to reflect the illness severity. Further more, the inflammatory cytokine IL-6 levels were significantly elevated in critically ill patients, which is almost 10-folds higher than those in other patients. More importantly, the extremely high IL-6 level was closely correlated with the incidence of RNAaemia (R=0.902) and the vital signs of COVID-19 patients (R= -0.682). Interpretation: Serum SARS-CoV-2 viral load (RNAaemia) is strongly associated with cytokine storm and can be used to predict the poor prognosis of COVID-19 patients. Moreover, our results strongly suggest that cytokine IL-6 should be considered as a therapeutic target in critically ill patients with excessive inflammatory response.