The March 2023 EMM Editor’s Choice Article is " Decrease of air pollution during lockdown in Tuscany (Italy): An effect on sperm DNA fragmentation?" (https://onlinelibrary.wiley.com/doi/10.1002/em.22530) by Costanza Calamai, Oumaima Ammar, Sara Marchiani, Selene Degl'Innocenti, Marisa Fino, Lorenzo Righi, Sara Dabizzi, Mario Maggi, Elisabetta Baldi, Linda Vignozzi, Monica Muratori.

Deaths resulting from noncommunicable diseases such as chronic respiratory illness, cancer, stroke and cardiovascular disease have been attributed to air pollution. Additionally, air pollutants might also have a role in the decreasing sperm counts and increasing male infertility observed world-wide. The findings from several studies evaluating conventional semen parameters support the negative effects of air pollution exposure on semen quality. Another promising marker for male fertility and reproductive outcomes is sperm DNA fragmentation (sDF), which is used as a measure of sperm DNA quality, and it has been reported that air pollution can increase sDF levels. The COVID pandemic resulted in a national lockdown being implemented in Italy beginning on March 9 2020 and continued until near normal activities resumed in June 2020. Data on daily air pollution levels collected by the Tuscany environmental protection agency indicated a significant reduction of many air pollutants in the region during the lockdown period.

In their January 2023 paper, Calamai and colleagues investigated whether the sDF levels and semen quality parameters had been affected during the lockdown in the Tuscany region of Italy. The study included patient data from couples with infertility issues undergoing sDF and semen analysis in the 6 months prior to, and 6 months following, the lockdown. The Investigators found that in the post-lockdown patient group, sperm progressive motility was increased, with a decrease in sDF levels and leucocyte concentration, and an increase in semen pH levels, as compared with the pre-lockdown patient group. All other semen parameters were unchanged. When the data were adjusted for confounding factors such as toxicant or high temperature exposure, lifestyle factors (smoking, alcohol use, sedentary or physical activity) varicocele, urogenital infection,  etc., patients analyzed after the lockdown still exhibited increased sperm motility and decreased sDF. As none of the other factors that could normally affect semen quality were readily attributable to the post-lockdown improvement in sperm motility and DNA quality, Calamai and colleagues suggested an alternative cause for the findings: the improved air quality brought about by decreased social and economic activity during the lockdown. Data on daily air pollution collected by the Tuscany environmental protection agency supported this alternative cause, indicating that most pollutant levels in the Tuscany region, where the patients were recruited, significantly decreased during the lockdown. While some limitations of the study were apparent to the Investigators, data from the study suggests a possible role for air pollutant exposure on sperm motility and DNA quality.