key: cord-0794370-0sbl0p1v authors: Pansini, R.; Fornacca, D. title: COVID-19 higher morbidity and mortality in Chinese regions with lower air quality date: 2020-05-30 journal: nan DOI: 10.1101/2020.05.28.20115832 sha: c7d2945724309ff34d32a540bea80247e2836510 doc_id: 794370 cord_uid: 0sbl0p1v We investigated the geographical character of the COVID-19 infection in China and correlated it with satellite- and ground-based measurements of air quality. Controlling for population size, we found more viral infections in those areas afflicted by high Carbon Monoxide, formaldehyde, PM 2.5, and Nitrogen Dioxide values. Higher mortality was also correlated with relatively poor air quality. Air pollution appears to be a risk factor for the incidence of this disease, similar to smoking. This suggests the detrimental impact of air pollution in these types of respiratory epidemics. COVID-19, initially detected in China and rapidly spread to the rest of the world, has ignited a pandemic at an exorbitant human cost. In a span of just over three months, eastern and western doctors, biologists, and sociologists alike have turned their attention at disentangling the aetiology of this disease. Various risk factors have been implicated with the fast spread of the virus, assuming different characters whether considered within or between countries. On an individual level, older age, male gender and smoking status have all been shown to increase the virulence of SARS-CoV-2 1 . From the standpoint of the natural sciences and evolution, we can take a broader perspective beyond virological and medical mechanisms to appreciate how a coronavirus transmitted once more from an animal species to us. Elements including human and livestock overpopulation, biodiversity loss and climate change played a critical role in making the ground suitable for a new epidemics to flourish 2,3 . Zoonoses should not be treated so that wildlife is blamed, the actual problem is the human exploitation of wildlife 4,5 . Pertaining to climate change, air pollution is notoriously known to cause health problems and, in particular, viral respiratory infections and pneumonia to individuals exposed for several days a year 6,7 . From our perspective as biologists, economists and geographers, we have investigated the expansion of the infection in China (with Hong Kong and Taiwan included data from the Chinese government health commission 8 ) and we have correlated it with the annual tropospheric column measurements of several air pollutants sampled from the Sentinel-5 satellite time series (data from the European Space Agency portal 9 ) as well as data derived from traditional air quality stations 10 . The data were updated on 23 May 2020, well after the first, main infection wave and they include the major 17 April update (at the time, an increase of 1,290 casualties, about 50% from the previous figure, and an increase of 325 infections for the city of Wuhan only). See Table 1 for a comprehensive summary of the data. Controlling for varying population sizes 11 , we find more viral infections and fatalities in those Chinese prefectures afflicted by common pollutants of the air: CO, HCHO, PM 2.5, PM 10, and NO2. All correlation tests were performed using Kendall's Tau with the significance threshold set to 0.05. Aerosol data from the satellite, which include PM 2.5 and PM 10, were not associated with a higher mortality. This is not surprising, they in fact comprise non-pollutant, inert particulates such as dust, sand and sea salt. On the other hand, statistics suggested that higher levels of O3 and SO2 were not associated to more COVID-19 deaths, which goes against the trends of the other pollutants, an aspect that requires further investigation. A comprehensive statistical output is reported in Table 2 . Despite the fact the SARS-CoV-2 was first detected in Wuhan and that the first location of the pathogen assumes a key role in the geographical spread of the infection, the detrimental effect that air pollution assumes at a national level remains evident. This trend in fact holds after removing (1) Wuhan city and (2) the whole Hubei province from the dataset in succession (see Table 2S .I. and £S.I.). Although the measures to contain the virus taken by the Chinese government were effective when compared to other countries affected by what later became a pandemic, the strong association between air pollution and higher morbidity and mortality rates can be detected even where the series of outbreaks originated from. Although free health care was dispensed to everyone in the exceptional case of this epidemics, the Chinese health system, as those ones of many other countries, is not adequate at including risk factors as comorbidity elements to prevent diseases and allow for free health care accordingly 12 . We hypothesise that the correlational significance we have found points towards air pollution as a critical risk cofactor for COVID-19, also because of other studies. (1) Testing the more proximal hypothesis that COVID-19 outbreaks could follow with a temporal delay from days with high NO2 presence in the air, colleagues in Shanghai are publishing detailed time series suggesting a delay of 12 days before hospitalisations for the Hubei province 13 . This may even suggest the role of air pollutants as airborne vectors for this virus 14 , later also suggested by another study 15 run in three cities in Hubei province. At a Chinese national level, PM 2.5 and NO2 pollution from ground stations was recently found correlated with this pathology incidence, after adjusting for some socioeconomic factors and human movements following the Spring festival 16 . (2) In the United States, chronic exposure to high levels of PM 2.5 have been found co-responsible for 20-time higher mortality rate of respiratory diseases, specifically in 2020, that is in presence of COVID-19 17 . This is a rate much higher than other American demographic covariables. (3) In Italy, a similar positive correlation controlling for further demographic variables was also reported 18 , with the additional and novel evidence that fragments of the RNA from this virus were found in the particulate matter of the harshly hit Italian city of Bergamo 14 . (4) Finally, our comprehensive study including eight countries assessed with a similar analysis, confirms this same trend in six out of eight countries 19 (we were in fact the very first to release an analysis comparing chronic exposure to air pollution and a higher morbidity and mortality from SARS-CoV-2 in early April 20 ). As a clear and immediate action to prevent the trajectory of this and future epidemics, curbing climate change 21,22 must be endorsed way more seriously. With no exceptions, it must be endorsed now. Will the smallest of the parasites be able to wake us up this time, so that we start caring about the health of the environment as much as we have been caring about our own and public health? . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 30, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 30, 2020. World Air Quality Index. Access date: 25/03/2020, https://aqicn.org/. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 30, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 30, 2020. . https://doi.org/10.1101/2020.05.28.20115832 doi: medRxiv preprint . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted May 30, 2020. . https://doi.org/10.1101/2020.05.28.20115832 doi: medRxiv preprint Health system reform in China: the challenges of multimorbidity. The Lancet Global Health Ambient nitrogen dioxide pollution and spread ability of COVID-19 in Chinese cities SARS-Cov-2 RNA Found on Particulate Matter of Bergamo in Northern Italy: First Preliminary Evidence. medRxiv Effect of ambient air pollutants and meteorological variables on COVID-19 incidence Risk of COVID-19 is associated with long-term exposure to air pollution Exposure to air pollution and COVID-19 mortality in the United States A Novel Methodology for Epidemic Risk Assessment: the case of COVID-19 outbreak in Italy Higher virulence of COVID-19 in the air-polluted regions of eight severely affected countries. medRxiv Initial evidence of higher morbidity and mortality due to SARS-CoV-2 in regions with lower air quality The Imperative for Climate Action to Protect Health Author Contributions Concept and design: RP. Acquisition and statistical analysis and of data: DF. Interpretation: DF and RP. Drafting of the manuscript: RP No funding was obtained for the completion of this study. Livia Ottisova improved and revised the manuscript. Chun Chen commented on statistics. RP did this work while in isolation in the Italian Po valley, due to the ongoing pandemic.