Impact of air pollution on SARS-CoV-2 induced health outcomes - a systematic review

Abstract

Background/Aim: Several authors suggested that ambient factors, such as ambient air pollution or outdoor air temperature, might be related to the number of cases and fatalities regarding the recently discovered Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). Despite the rapidly increasing number of publications associations between these environmental stimuli and SARS-CoV-2 are still controversial. Methods: We will conduct a systematic literature review with a focus on the following hypotheses: i) High levels of ambient air pollution impair the immune defence and make humans more vulnerable to SARS-CoV-2. ii) Ambient air pollution and / or non-optimal ambient temperatures lead to (chronic) diseases which make the human body more vulnerable to SARS-CoV-2. iii) Ambient air pollutants actively transport viruses. iv) Climatic conditions like temperature or humidity affect SARS-CoV-2 related health conditions and/or have an impact on the survival of the virus in the environment. Due to the differing quality of the studies, many of which have been published with great speed, a focus will be on the quality assessment of the studies. Results: Currently, the number of published studies varies extremely, with the lowest number of publications for hypothesis iv). This review will give a systematic overview on the strength and robustness of the suggested hypotheses. Conclusions: Although there already seems to be scientific evidence implying that environmental factors such as air pollutants or air temperature impact SARS-CoV-2 related health outcomes, there is the need for further research with high quality to improve and strengthen the knowledge on these associations.