Research progress of microbes in subway air / 环境与职业医学

Accumulating studies suggest that, as the subway is one of the important means of transport in cities, airborne microorganisms in its system have potential effects on human health, but previous studies have mainly focused on some foreign cities. We reviewed the spatio-temporal distribution characteristics of airborne microorganisms in subway stations in different cities, including diurnal, weekly, and seasonal variations, and the distribution of microorganisms in different regions of the world. The factors affecting airborne microorganisms, such as human activities, temperature and humidity, ventilation, and particulate matter, were presented. The potential health effects were described. Although there was no significant risk of infection from using subway, many pathogens do exist in the air. The influence of microorganisms in subway air on health has become a public health problem that cannot be ignored.

Spatial Correlation of Particulate Matter Pollution and Death Rate of COVID-19

The Coronavirus (COVID-19) epidemic, which was first reported in December 2019 in Wuhan, China, has caused 3,314 death as of March 31, 2020 in China. This study aimed to investigate the spatial associations of daily particulate matter (PM) concentrations with death rate of COVID-19 in China. We conducted a cross-sectional analysis to examine the spatial associations of daily PM2.5 and PM10 concentrations with death rate of COVID-19 in China through multiple linear regression method. We found that COVID-19 held higher death rates with increasing concentration of PM2.5 and PM10 levels in the spatial scale, which may affect the process of patients developed from mild to severe and finally influence the prognosis of COVID-19 patients.

Temporal Association Between Particulate Matter Pollution and Case Fatality Rate of COVID-19 in Wuhan, China

The Coronavirus (COVID-19) epidemic, which was first reported in December 2019 in Wuhan, China, has caused 3,314 death as of March 31, 2020 in China. This study aimed to investigate the temporal association between case fatality rate (CFR) of COVID-19 and particulate matter (PM) in Wuhan. We conducted a time series analysis to explore the temporal day-by-day associations. We found COVID-19 held higher case fatality rate with increasing concentrations of PM2.5 and PM10 in temporal scale, which may affect the process of patients developed from mild to severe and finally influence the prognosis of COVID-19 patients.

Ambient nitrogen dioxide pollution and spread ability of COVID-19 in Chinese cities

The Coronavirus (COVID-19) epidemic, which was first reported in December 2019 in Wuhan, China, has caused 219,331 confirmed cases as of 20 March 2020, with 81,301 cases being reported in China. It has been declared a pandemic by the World Health Organization in 11 March 2020 (1). Although massive intervention measures have been implemented in China (e.g. shutting down cities, extending holidays and travel ban) and many other countries, the spread of the disease are unlikely to be stopped over the world shortly. It is becoming evident that environmental factors are associated with seasonality of respiratory-borne diseases epidemics (2). Previous studies have suggested that ambient nitrogen dioxide (NO2) exposure may play a role in the phenotypes of respiratory diseases, including, but not limited to, influenza, asthma and severe acute respiratory syndrome (SARS). NO2), for example, might increase the susceptibility of adults to virus infections (3). High exposure to NO2 before the start of a respiratory viral infection is associated with the severity of asthma exacerbation (4). This study aims to assess the associations of ambient NO2 levels with spread ability of COVID-19 across 63 Chinese cities, and provides information for the further prevention and control of COVID-19.

Aerodynamic Characteristics and RNA Concentration of SARS-CoV-2 Aerosol in Wuhan Hospitals during COVID-19 Outbreak

BackgroundThe ongoing outbreak of COVID-19 has spread rapidly and sparked global concern. While the transmission of SARS-CoV-2 through human respiratory droplets and contact with infected persons is clear, the aerosol transmission of SARS-CoV-2 has been little studied. MethodsThirty-five aerosol samples of three different types (total suspended particle, size segregated and deposition aerosol) were collected in Patient Areas (PAA) and Medical Staff Areas (MSA) of Renmin Hospital of Wuhan University (Renmin) and Wuchang Fangcang Field Hospital (Fangcang), and Public Areas (PUA) in Wuhan, China during COVID-19 outbreak. A robust droplet digital polymerase chain reaction (ddPCR) method was employed to quantitate the viral SARS-CoV-2 RNA genome and determine aerosol RNA concentration. ResultsThe ICU, CCU and general patient rooms inside Renmin, patient hall inside Fangcang had undetectable or low airborne SARS-CoV-2 concentration but deposition samples inside ICU and air sample in Fangcang patient toilet tested positive. The airborne SARS-CoV-2 in Fangcang MSA had bimodal distribution with higher concentration than those in Renmin during the outbreak but turned negative after patients number reduced and rigorous sanitization implemented. PUA had undetectable airborne SARS-CoV-2 concentration but obviously increased with accumulating crowd flow. ConclusionsRoom ventilation, open space, proper use and disinfection of toilet can effectively limit aerosol transmission of SARS-CoV-2. Gathering of crowds with asymptomatic carriers is a potential source of airborne SARS-CoV-2. The virus aerosol deposition on protective apparel or floor surface and their subsequent resuspension is a potential transmission pathway and effective sanitization is critical in minimizing aerosol transmission of SARS-CoV-2.

Effectiveness of intervention strategies for Coronavirus Disease 2019 and an estimation of its peak time

BackgroundSince its first cases occurrence in Wuhan, China, the Coronavirus Disease 2019 (COVID-19) has been spreading rapidly to other provinces and neighboring countries. A series of intervention strategies have been implemented, but didnt stop its spread. MethodsTwo mathematical models have been developed to simulate the current epidemic situation in the city of Wuhan and in other parts of China. Special considerations were given to the mobility of people for the estimation and forecast the number of asymptomatic infections, symptomatic infections, and the infections of super-spreading events (Isse). FindingsThe basic reproductive number (R0) was calculated for the period between 18 January 2020 and 16 February 2020: R0 declined from 5.75 to 1.69 in Wuhan and from 6.22 to 1.67 in the entire country (not including the Wuhan area). At the same time, Wuhan is estimated to observe a peak in the number of confirmed cases around 6 February 2020. The number of infected individuals in the entire country (not including the Wuhan area) peaked around February 3. The results also show that the peak of new asymptomatic cases per day in Wuhan occurred on February 6, and the peak of new symptomatic infections have occurred on February 3. Concurrently, while the number of confirmed cases nationwide would continue to decline, the number of real-time COVID-19 inpatients in Wuhan has reached a peak of 13,030 on February 14 before it decreases. The model further shows that the COVID-19 cases will gradually wane by the end of April 2020, both in Wuhan and the other parts of China. The number of confirmed cases would reach the single digit on March 27 in Wuhan and March 19 in the entire country. The five cities with top risk index in China with the exclusion of Wuhan are: Huanggang, Xiaogan, Jingzhou, Chongqing, and Xiangyang city. InterpretationsAlthough the national peak time has been reached, a significant proportion of asymptomatic patients and the infections of super-spreading events (Isse) still exist in the population, indicating the potential difficulty for the prevention and control of the disease. As the Return-to-Work tide is approaching and upgrading, further measures (e.g., escalatory quarantine, mask wearing when going out, and sit apart when taking vehicles) will be particularly crucial to stop the COVID-19 in other cities outside of Wuhan. What was already known about the topic concernedCurrently, a Coronavirus Disease 2019 (COVID-19) is thought to have emerged into the human population in Wuhan, and cases have been identified in neighboring provinces and other countries. In existing epidemiological studies, the basic reproduction number (R0) of the virus were estimated between 1.4 and 5. Besides, it is of crucial importance to evaluate and improve different intervention strategies which have already implemented. What new knowledge the manuscript contributesIn this study, two mathematical models were established to simulate the current epidemic situation and predict the future trend of the COVID-19. We found that with the implementation of different policies, R0 continued to decline over time and the number of confirmed cases in Wuhan will peak on around February 6. Also, we estimated and forecast the number of asymptomatic infections, symptomatic infections, and infections of super-spreading events caused by the COVID-19 and the risk index of different cities. Implications of all the available evidenceOur research has important practical implications for public health policy makers. Although the current prevention and control measures have made some significant inroads into controlling the epidemic, complete control has not yet been achieved. We recommend that self-isolation at home be strictly observed for a period of time in the future. Furthermore, our estimation of the number of asymptomatic people, super spreading and real-time inpatients would provide basis guidance for the hospital to arrange beds accordingly.

Impact of fine particulate matters on the daily number of emergency visits and outpatient visits of 5 hospitals in Beijing, Shanghai, and Guangzhou, 2013-2015 / 中华预防医学杂志

Objective@#To explore the effect of fine particulate matters (PM2.5) exposure on emergency visits and outpatient visits of 5 hospitals in Beijing, Shanghai and Guangzhou from 2013 to 2015.@*Methods@#Using convenient sampling method, 5 general hospitals in Beijing, Shanghai and Guangzhou were selected which included Beijing hospital, China-Japan friendship hospital, Xinhua hospital affiliated to Shanghai jiaotong University School of Medicine, the liwan hospital of the third affiliated hospital and the first affiliated hospital of Guangzhou Medical University. The emergency and outpatient data, air pollution monitoring data and meteorological data were collected from January 1, 2013 to December 31, 2015. A generalized additive model was used to analyze the effect of PM2.5 exposure on daily hospital emergency and outpatient visits, and Meta analysis was used to obtain the combined effect value.@*Results@#The number of emergency and outpatient visits of 5 hospitals was 1 378 501 and 18 139 779 in total, respectively. The mean±SD of PM2.5 exposures in Beijing hospital, China-Japan friendship hospital, Xinhua hospital affiliated to Shanghai jiaotong University School of Medicine, the liwan hospital of the third affiliated hospital and the first affiliated hospital of Guangzhou Medical University were (81.8±68.7), (83.2±69.7), (54.4±34.1), (43.5±24.8) μg/m3, respectively. Results of single pollutant model analysis showed that 0-1 day lag concentrations of PM2.5 had the largest effect on emergency visits and outpatient visits. For a 10 μg/m3 increase of PM2.5 concentration, excess risk (ER) (95%CI) of emergency and outpatient visits was 0.56% (0.14%, 0.99%) and0.63% (0.07%, 1.19%), respectively. After adjusting for O3, NO2, SO2, and CO, for a 10 μg/m3 increase of PM2.5 concentrations, the ER (95%CI) of emergency visits was 0.50% (0.10%, 0.90%), 0.34% (-0.02%, 0.69%), 0.36% (0.02%, 0.69%) and 0.56% (0.10%, 1.03%), respectively and the ER (95% CI) of outpatient visits was 0.65% (0.08%, 1.21%), 0.29% (-0.17%, 0.75%), 0.48% (-0.06%, 1.03%) and 0.48%(-0.02%, 0.99%), respectively.@*Conclusion@#Our results suggested that PM2.5 exposure can increase emergency and outpatient visits of 5 hospitals in Beijing, Shanghai and Guangzhou.

Research progress of ambient air pollution and human health in China / 中华预防医学杂志

As one of the major environmental and health problems in China, ambient air pollution has attracted substantial public concerns. This paper reviews the current evidence on air pollution and population health in China, including acute health effect studies, chronic health effect studies, disease burden, and interventions studies. Future research directions are also discussed.

Review on methods in the disease burden assessment attributable to household air pollution / 中华预防医学杂志

In the past decades, people's work and life styles have dramatically changed during the rapid economic development and urbanization in China. A national survey reported that Chinese adults spend an average of 81% of daily time in indoor environment. Exposure to indoor air pollution plays key roles for human health but is likely to be neglected due on the relatively lower concentration levels and lower awareness among common people. Till now, published studies focus more on the pollution levels or the toxicological effects of indoor air pollutants but there is a lack of disease burden assessment attributable to indoor air pollution. In this review, several international studies were introduced on the disease burden estimation attributable to indoor air pollution, as well as the estimation methods. The current situation of national study was also reviewed. The strengths and limitations of the representative international studies were discussed. This review is helpful in providing data to guide the research on disease burden assessment attributable to indoor air pollution in China, and further helps to prioritize the indoor air pollution control based on disease burden ranking among pollutants and motivate public policies to protect the public health.

The effects of air pollution on adverse birth outcomes.

BACKGROUND: Air pollution has been shown to have adverse effects on many health outcomes including cardiorespiratory diseases and cancer. However, evidence on the effects of prenatal exposure is still limited. The purpose of this retrospective cohort study is to evaluate the effects of prenatal exposure to air pollutants including particulate matter with aerodynamic diameter less than 2.5 µm (PM2.5) and ozone (O3) on the risk of adverse birth outcomes (ABOs) including term low birth weight (LBW), preterm delivery (PTD) and very PTD (VPTD). METHODS: singleton births from 2004 to 2005 in Florida were included in the study (N=423,719). Trimester-specific exposures to O3 and PM2.5 at maternal residence at delivery were estimated using the National Environmental Public Health Tracking Network data, which were interpolated using Hierarchical Bayesian models. RESULTS: After adjustment for potential confounders such as demographics, medical and lifestyle factors PM2.5 exposures in all trimesters were found to be significantly and positively associated with the risk of all ABOs. Second-trimester exposure had the strongest effects. For an interquartile range (IQR) increase in PM2.5 during the second trimester, the risk of term LBW, PTD and VPTD increased by 3% [95% confidence interval (CI): 1-6%)], 12% (11-14%) and 22% (18-25%), respectively. O3 was also found to be positively associated with PTD and VPTD with the strongest effects over the whole pregnancy period [3% (1-5%) for PTD and 13% (7-19%) for VPTD for each IQR increase]. However, O3 was observed to have protective effects on term LBW. Results were consistent for multi-pollutant models. CONCLUSION: PM2.5 has consistent adverse effects on ABOs whereas O3 has inconsistent effects. These findings warrant further investigation.

Effects of daily mean temperature on respiratory hospital admissions in Shanghai: time-series analysis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To quantitatively evaluate the effects of daily mean temperature on respiratory diseases.</p><p><b>METHODS</b>Based on the data of daily hospital admissions for respiratory diseases, meteorological parameters and air pollution in Shanghai between January 2006 and December 2011, we used a generalized additive model (GAM) to explore the effects of daily mean temperature on hospital admissions on respiratory diseases adjusted for the secular trend, seasonal trend, day of week and other confounders.</p><p><b>RESULTS</b>A J-shaped relationship was found between daily mean temperature and respiratory disease and the optimum temperature (OT) corresponding to low risk of respiratory hospital admissions was about 25 °C. For cold effects over lag 0-30 days, the overall excess risk (ER) of hospital admission associated with 1 °C below the OT was 3.00% (95% CI: 2.54%-3.45%), 3.00% (95% CI: 2.55%-3.45%) and 3.02% (95% CI:2.51%-3.49%) for overall, males and females, respectively. For hot effects over lag 0-30 days, the overall excess risk (ER) was 2.15% (95% CI: 0.67%-3.66%), 1.86% (95% CI: 0.39%-3.34%) and 2.57% (95% CI: 0.82%-4.36%) for overall, males and females, respectively. The optimum temperature between daily mean temperature and respiratory disease were 14 °C, 20 °C, 25 °C and 28 °C in different age groups. The effect of low temperature increased with age for the people above 45 years old; however the effect of high temperature was significant for the people under 65 years old.</p><p><b>CONCLUSIONS</b>Both of higher temperature and lower temperature resulted in ER of respiratory hospital admissions increase with lag effects. The effects of lower temperature lagged longer and stronger than higher temperature. Different age group and gender shows different effects.</p>

Daily visibility and hospital admission in Shanghai, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The study is to investigate the associations between visibility, major air pollutants and daily counts of hospital admission in Shanghai, China.</p><p><b>METHODS</b>Daily data on hospital admission, visibility, and air pollution during 2005-2008 were obtained from the Shanghai Insurance Bureau (SHIB), Shanghai Meteorological Bureau, and Shanghai Environmental Monitoring Center, respectively. The generalized additive model (GAM) with penalized splines was used to examine the associations between daily visibility and hospital admission.</p><p><b>RESULTS</b>Among various pollutants, PM(2.5) showed strongest correlation with visibility. Decreased visibility was significantly associated with increased risk of hospital admission in Shanghai. An inter-quartile range decrease in the 2-day (L01) moving average of visibility corresponded to 3.66% (95%CI: 1.02%, 6.31%), 4.06% (95%CI: 0.84%, 7.27%), and 4.32% (95%CI: 1.67%, 6.97%) increase of total, cardiovascular, and respiratory hospitalizations, respectively.</p><p><b>CONCLUSION</b>Our analyses provide the first piece of evidence in China, demonstrating that decreased visibility has an effect on hospital admission, and this finding strengthens the rationale for further limiting air pollution levels in Shanghai.</p>

Diurnal temperature range as a novel risk factor for sudden infant death / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To assess the relationship between diurnal temperature range (DTR) and sudden infant death (SID) between 2001 and 2004 in Shanghai, China.</p><p><b>METHODS</b>We conducted a time-stratified case-crossover analysis to estimate the percent increase of SID associated with changes in DTR after adjustment for daily weather conditions (temperature and relative humidity) and outdoor air pollution.</p><p><b>RESULTS</b>DTR was significantly associated with daily SID. An increase of 1 °C in the current-day (L0) and in the 2-day moving average (L01) DTR corresponds to a 1.56% (95% CI: 0.97%, 2.15%) and a 1.89% (95% CI: 1.17%, 2.60%) increase in SID, respectively.</p><p><b>CONCLUSION</b>An increased DTR was associated with an increased risk of SID in Shanghai. More studies are needed to understand the effect of DTR on infant deaths.</p>

Air pollution and population health: a global challenge

"Air pollution and population health" is one of the most important environmental and public health issues. Economic development, urbanization, energy consumption, transportation/motorization, and rapid population growth are major driving forces of air pollution in large cities, especially in megacities. Air pollution levels in developed countries have been decreasing dramatically in recent decades. However, in developing countries and in countries in transition, air pollution levels are still at relatively high levels, though the levels have been gradually decreasing or have remained stable during rapid economic development. In recent years, several hundred epidemiological studies have emerged showing adverse health effects associated with short-term and long-term exposure to air pollutants. Time-series studies conducted in Asian cities also showed similar health effects on mortality associated with exposure to particulate matter (PM), sulfur dioxide (SO(2)), nitrogen dioxide (NO(2)) and ozone (O(3)) to those explored in Europe and North America. The World Health Organization (WHO) published the "WHO Air Quality Guidelines (AQGs), Global Update" in 2006. These updated AQGs provide much stricter guidelines for PM, NO(2), SO(2) and O(3). Considering that current air pollution levels are much higher than the WHO-recommended AQGs, interim targets for these four air pollutants are also recommended for member states, especially for developing countries in setting their country-specific air quality standards. In conclusion, ambient air pollution is a health hazard. It is more important in Asian developing countries within the context of pollution level and population density. Improving air quality has substantial, measurable and important public health benefits.

The cytotoxic effects of extracts from dominant indoor airborne fungal culture / 医学研究生学报

Objectine:To study the cytotoxicity of extracts of dominant indoor airborne fungal culture. Methods:Chinese hamster lung(CHL) cell culture was carried out in vitro.Cells were exposed to extracts of dominant indoor airborne fungal culture,then MTT method and CHL colonies assay were performed to detect their cytotoxicity.The release of cytosolic enzyme Lactate Dehydrogenase(LDH) and the fluidity of K~+,Ca~(2+) were analysed. Results:With the increase of the dose,the LDH levels in culture medium increased and the Ca~(2+) concentration inside cells increased while the K~+ concentration inside cells decreased accordingly. Conclusion:The extracts of dominant indoor airborne fungal culture could damage cell membrane,and have cytotoxicity.

Methodological Research on the Health-based Risk Assessment on Air Pollution / 环境与健康杂志

Objective To get comprehensive and quantitative evaluation of the impact of ambient air pollution on human health. Methods The approach recommended in this paper is a quantitative estimate on the health impact from exposure to air pollutants based on the internationally accepted quantitative risk assessment framework and the per unit increase in mortality or morbidity due to per unit increase of air pollutants levels. Results A schematic diagram of health-based risk assessment on air pollutants is presented. Calculation for excess deaths and excess disease cases is also provided. Conclusion This approach could be used for comparing the health effects associated with exposure to air pollutants of various Chinese cities in different time periods and is also useful in the priority setting of air pollution intervention and improvement measures and health-based cost benefit analysis.

Association of Air Pollution With Daily Mortality in Zhabei District of Shanghai: a Case,Crossover Analysis / 环境与健康杂志

Objective To assess the association of air pollution with daily mortality among residents of Zhabei district in Shanghai. Methods Case,crossover analysis and conditional Logistic regression model were used to analyze the association of air pollution with daily mortality of residents in Zhabei district of Shanghai from June 2000 to December 2002. Results Using a symmetric bi,directional control sampling approach, the results obtained from a conditional logistic regression model with four reference periods after controlling for weather conditions showed that the OR of non,accidental mortality associated with each 10 ?g/m3 increment of PM10, SO2 and NO2 over a 48,hr moving average were 1.007(95%CI 1.003-1.011),1.011(95%CI 1.001-1.021),1.010(95%CI 1.000-1.020)respectively. Similar associations were observed between mortality of cardiovascular diseases and PM10, mortality of respiratory diseases and NO2. Also, PM10 was associated with mortality in a sensitivity analysis. Conclusion The acute effect of air pollution on mortality of the general population was established in Zhabei district of Shanghai.

Analysis of Exposure-Response Relationships of Air Particulate Matter and Adverse Health Outcomes in China / 环境与健康杂志

Objective To analyze the epidemiological data on air particulate matter and adverse health outcomes in China, and to estimate the exposure_response relationships. Methods An electronic search of relevant literature was conducted to determine the exposure_response relationship for each health outcome associated with exposure to air particulate matter, and the approach of Meta_analysis was used when there were several studies describing the same health endpoint. Results For each health outcome from morbidity to mortality changes, the relative risks were estimated when the concentration of air particulate matter increased some certain units. Conclusion The exposure_response relationships described here might be further applied to health risk assessment of air particulate matter in China.