Semen quality as a potential susceptibility indicator to SARS-CoV-2 insults in polluted areas

Abstract

The epidemic of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has impacted worldwide with its infectious spread and mortality rate. Thousands of articles have been published to tackle this crisis and many of these have indicated that high air pollution levels may be a contributing factor to high outbreak rates of COVID-19. Atmospheric pollutants, indeed, producing oxidative stress, inflammation, immuno-unbalance, and systemic coagulation, may be a possible significant co-factor of further damage, rendering the body prone to infections by a variety of pathogens, including viruses. Spermatozoa are extremely responsive to prooxidative effects produced by environmental pollutants and may serve as a powerful alert that signals the extent that environmental pressure, in a specific area, is doing damage to humans. In order to improve our current knowledge on this topic, this review article summarizes the relevant current observations emphasizing the weight that environmental pollution has on the sensitivity of a given population to several diseases and how semen quality, may be a potential indicator of sensitivity for virus insults (including SARS-CoV-2) in high polluted areas, and help to predict the risk for harmful effects of the SARS-CoV-2 epidemic. In addition, this review focused on the potential routes of virus transmission that may represent a population health risk and also identified the areas of critical importance that require urgent research to assess and manage the COVID-19 outbreak.

Keywords: Air pollution; COVID-19; Environmental marker; Health marker; Oxidative stress; SARS-CoV-2; Semen quality.

Fig. 1

Amount of PM2.5; PM10 and nitrogen dioxide in Wuhan (left) and in other cities of China (right) (data from https://www.kaggle.com/)

Fig. 2

c Death mediated by indoor and outdoor air pollution worldwide. An air pollution color intensity illustrating the global death rate produced by indoor air pollution. The percentage displays the rate of death due to indoor air pollution in comparison to other diseases. d The number of indoor air pollution deaths in 1990 compared to 2017. e Death from indoor air pollution age-dependent. Older people over 69 are at greater risk for indoor air pollution. f Rate of indoor air pollution per 100,000 people in 1990 compared to 2017 country distribution. Increasing indoor air pollution is a global concern (Source Institute for Health Metrics and Evaluation 2020 under creative common license attribution). Panels c, d, f, and e were reused from Fig. 3 of Paital B, Agrawal PK. Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review. Environ Chem Lett. 2020 Sep 18:1-18. doi: 10.1007/s10311-020-01091-w obtained with License Number 4971970782195

Fig. 3

Panel a shows the world map of tropospheric NO2 concentrations from the Sentinel-5P satellite (2018). The values were measured daily for 90 days, from June to August 2018 (Chow ; Environmental Protection Agency, , Myllyvirta and Howard 2020) (a). Panel b shows instead the world global death rate (%) by air pollution map in comparison with other diseases. Color intensity illustrating the global mortality rate due to air pollution (b). Panels a and b were reused from Fig. 3 of Paital B, Agrawal PK. Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review. Environ Chem Lett. 2020 Sep 18:1-18. doi: 10.1007/s10311-020-01091-w obtained with License Number 4971970782195

Fig. 4

The figure shows the decrease of the sperm concentration (million/mL) observed in North America, South America, Europe, Asia, and Africa from 1980/85 to 2010/15 (Agarwal et al. 2015). The mean decrease of the sperm concentration in the word in those years has been about 57%