key: cord-0913711-5ovdheh2 authors: Ma, Runmei; Du, Peng; Li, Tiantian title: Climate change, environmental factors and COVID-19: Current evidence and urgent actions date: 2021-06-18 journal: Innovation (N Y) DOI: 10.1016/j.xinn.2021.100138 sha: 5117a5eb877b005f75d52ecfa98c7fca504fd5ef doc_id: 913711 cord_uid: 5ovdheh2 nan The novel coronavirus disease (COVID-19) has triggered an international health crisis that began in late 2019. The number of COVID-19 cases globally remains at the highest levels, and variants of the SARS-CoV-2 being reported around the world have caused special concern. The COVID-19 pandemic requires a regular global response. As is the case with other infectious respiratory diseases, COVID-19 may be affected by climatic, meteorological and environmental factors, including temperature, humidity and air pollutants. The interactive effects of these factors on population health are complicated. Furthermore, policy responses to COVID-19 have substantially affected socio-economic systems and people's lifestyles, which in turn had an impact on climate by reducing emissions and population adaptations under the background of climate change, and even further affected the human health. Immediate actions are needed to respond to both climate change and COVID-19, and in turn the climate impacts of the COVID-19 pandemic. Existing studies mostly focus on the complex relationship between meteorological conditions (temperature, humidity) and COVID-19 (confirmed cases, basic reproduction number (R 0 )) under the short-term exposure window. However, a particular contradiction has been identified in current evidence. Some studies have reported that low temperatures and dryness increase the health risks of COVID-19; the underlying mechanism is explained as the impact of meteorological conditions on SARS-CoV-2, and immune system resistance. However, the J o u r n a l P r e -p r o o f opposite conclusion is that the trend of the epidemic and seasonal changes is more attributed to the effectiveness of epidemic prevention measures over time 1 Air pollutants such as PM 2.5 , PM 10 , NO 2 , SO 2 and O 3 were linked to confirmed cases, R 0 and the fatality rate of COVID-19. Middle-term or long-term exposure to air pollutants (monthly or annual averages) was of great concern. In the United State, an increase of 1 μg/m 3 in the long-term average PM 2.5 was associated with a statistically significant 11% increase in the county's COVID-19 mortality rate 2 ; and per interquartile-range increase in NO 2 (4.6 ppb) was associated with 11.3% and 16.2% increase of COVID-19 case-fatality rate and mortality rate respectively 3 . Under long-term particulate matter exposure, the overexpression of alveolar angiotensin-converting enzyme 2 receptor and impairment of host defenses may be triggered 2 . Chronic NOx exposure may induce inflammation and enhance oxidative stress 3 . The implementation of lockdown measures for COVID-19 leads to a significant decline in human activities and energy consumption, which also affects meteorological factors and air pollution. Due to a decline in surface-transport emissions, global fossil-fuel CO 2 emissions and total NOx emissions decreased, contributing to a short-term cooling since the start of 2020 4 . However, the global temperature response will probably be small because it does not reflect structural changes in the economy or transport and energy systems 4 . Emissions reductions are J o u r n a l P r e -p r o o f also reflected in air pollution levels. During the quarantine period in China (February 10 to March 14, 2020), NO 2 and PM 2.5 dropped 12.9 µg/m³ and 18.9 µg/m³, which further prevented related death 5 . Moreover, the coupling relationship may exist among different air pollutants, leading to various shifting trends. Current COVID-19 studies are not comprehensive enough to fully assess the relationships and interactions between meteorological factors, air pollution or other environmental factors and COVID-19. The studies related to seasonal patterns, middle-and long-term effects during the pandemic are limited. Methodological advancements, like multi-site and individual-level studies using novel statistical methods and comprehensive control of potential confounders (such as the timeline of response measurements, the level of the epidemic prevention policy, healthcare policy and quality, and the population migration), are needed. Further study of sensitive populations and their specific risks is also needed to support targeted policy-making for vulnerable groups. Furthermore, more communication and cooperation between researchers working in climate science and infectious disease epidemiology are needed to avoid deviations in research conclusions due to disciplinary differences. The interactive nature of climate-attributable risks and the global COVID-19 crisis may J o u r n a l P r e -p r o o f continue for a long time. Countermeasures for extreme events will have an impact on COVID-19 control measures, such as the maintenance of social distancing for COVID-19 and the gathering in emergency shelter for extreme events . Furthermore, due to a legacy of racial discrimination and under-investment in healthcare, vulnerable populations, particularly the poor, are susceptible to both extreme weather and COVID-19. This presents a huge policy challenge in accurately identifying health risks and protecting vulnerable populations. The human health and economic losses caused by COVID-19 have exposed the current inadequacies of disaster response systems. Precautionary approaches including preemptive technical assistance and funding are needed. A framework based on multi-department collaboration with clear rights and responsibilities is indispensable to formulate suitable emergency response measures and recommendations for protection of the public. Early warning systems and long-term projections of future pandemics are required to prevent or mitigate potential public health crises in a changing climate. The Global Influenza Surveillance and Response System, which monitors the spread and evolution of influenza, has contributed significantly to country-level diagnostic and sequencing capabilities throughout the COVID-19 response. On the basis of reliable epidemiological evidence, monitoring and response systems need to comprehensively consider the potential impacts of climate and environmental factors on the development of disease epidemics, so as to make promptly early warnings and scientific planning. J o u r n a l P r e -p r o o f No Association of COVID-19 transmission with temperature or UV radiation in Chinese cities Air pollution and COVID-19 mortality in the United States: Strengths and limitations of an ecological regression analysis Urban Air Pollution Case-Fatality and Mortality Rates in the United States. The Innovation Current and future global climate impacts resulting from COVID-19 Air pollution reduction and mortality benefit during the COVID-19 outbreak in China Although the response to the COVID-19 pandemic is currently the highest priority action in the world, a long-term and sustainable strategy, coping with climate change, should not be