Abstract

Epidemiological studies have shown that respiratory viral infections have been associated with air pollutants exposure. So that, the increased incidence of SARS-CoV-2 infection and mortality from COVID-19 is related to exposure to urban air pollution. In addition, changes in meteorological parameters have been involved in air pollution and the incidence and development of COVID-19. Although, the molecular mechanisms by which exposure to air pollutants affects COVID-19 are still unknown and it is not yet clear how the virus is transmitted from one sick person to another and why it is so transmissible. Viruses can be probably transmitted through speech and exhalation aerosols. Findings show that SARSCoV- 2 aerosol transmission is possible. Spike (S) proteins of SARS CoV-2 determine tissue tropism using an angiotensin-converting enzyme receptor type2 (ACE-2) to bind to the cells. This mini-review briefly describes the COVID-19 biology and the viral transmission route and explains the relationship between air pollution exposure and COVID-19, and helps us anticipate the potential role of urban air pollution in the spread of COVID-19.

Keywords: COVID-19; Air pollution exposure; Nanoparticles; Airborne Particulate matter

Abbreviations:Ang I: Angiotensin I; Ang II: Angiotensin II; Ang II (1-7): Angiotensin-(1-7); ARDS: Acute Respiratory Distress Syndrome; ACE: Angiotensin-Converting Enzyme; ACE2: Angiotensin-Converting Enzyme 2; AT1R: Angiotensin II type 1 receptor; ANE: Acute Necrotizing Encephalopathy; BBB: Blood– Brain Barrier; OB: Olfactory Bulb; HI: Hippocampus; CO: Carbon Monoxide; CNS: Central Nervous System; COVID-19: Coronavirus Disease 2019; ERK: Extracellular signal-Regulated Kinase; IL: Interleukin; NO2: Nitrogen Dioxide; O3: Ozone; PM: Particulate Matter; PM0.1: Particulate Matter<0.1μm (ultrafine particles); PM2.5: Particulate Matter<2.5μm (fine particles); PM10: Particulate Matter with a diameter between 2.5μm and 10μm (coarse particles); RBD: Receptor Binding Domain; ROS: Reactive Oxygen Species; RAS: Renin Angiotensin System; SO2: Sulfur Dioxide; STAT3: Signal Transducer and Activator of Transcription 3; SARS: Severe Acute Respiratory Syndrome; SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus 2; TNFα: Tumor Necrosis Factor alpha; INFγ: Interferon-gamma; UFPs: Ultra-Fine Particles; US: United States; HCOV: Human Coronavirus