Air pollution, whether from household sources like cooking and heating or from outdoor sources like vehicle emissions and industrial processes, poses a significant threat to health. Almost the entire global population are exposed to dangerous levels of air polluation and breathes air that exceeds the World Health Organization’s safety limits. This widespread exposure contributes to various diseases, including those affecting reproductive health.
In today’s industrialized world, air pollution has emerged as a silent but potent threat to public health, with far-reaching implications. Among these, the impact on male reproductive health has garnered significant attention. Researchers led by Dr. Temidayo Omolaoye and Professor Stefan Du Plessis from Mohammed Bin Rashid University of Medicine and Health Sciences, Dr. Bongekile Skosana, Lisa Ferguson, and Yashthi Ramsunder from Stellenbosch University, and Dr. Bashir Ayad from Misurata University have explored this critical issue. Their findings, published in the peer-reviewed journal Antioxidants, shed light on the mechanisms through which air pollution affects male fertility, emphasizing the role of oxidative stress.
Dr. Omolaoye explained that air pollutants can increase the production of reactive oxygen species (ROS), leading to oxidative stress, lipid peroxidation, and DNA damage. “Air pollution is one of the world’s leading environmental causes of disease, responsible for millions of deaths annually and contributing significantly to the global disease burden,” Dr. Omolaoye stated. These pollutants, whether from household activities or industrial emissions, have severe implications for human health, particularly male reproductive health.
The researchers conducted a comprehensive review of the literature from both human and animal studies to assess the impact of air pollution on semen quality and male sexual health. They found that exposure to air pollutants is associated with reduced sperm concentration, motility, and morphology, as well as DNA fragmentation and other genetic abnormalities. These findings underscore the detrimental effects of air pollution on sperm quality and highlight the need for urgent interventions to mitigate these risks.
Animal studies have consistently shown that air pollutants like particulate matter with aerodynamic diameters of ≤2.5µm (PM2.5) and sulfur dioxide (SO2) can significantly reduce sperm count and motility, and increase abnormal sperm morphology. In one study, Sprague–Dawley rats exposed to PM2.5 presented with reduced sperm count and increased abnormal morphology. Similarly, exposure to SO2 was found to decrease sperm quality and alter testicular morphology.
Human studies corroborate these findings. For instance, a large cohort investigation in China revealed that exposure to PM2.5 and PM10 significantly decreased sperm concentration and motility. Another analysis in the United States found a negative correlation between PM2.5 exposure and sperm motility after a few months of exposure.
The research also delves into the advanced parameters of semen analysis, including DNA fragmentation and chromatin integrity. Exposure to air pollutants has been shown to cause DNA–protein crosslinks, leading to significant DNA damage. Dr. Omolaoye noted, “Pollution-induced DNA fragmentation is a critical biomarker of sperm quality, indicating the severe impact of environmental pollutants on male reproductive health.”
Furthermore, air pollution has been linked to changes in gene expression through epigenetic modifications, such as DNA methylation and histone modifications. These changes can disrupt the normal function of genes involved in inflammation, oxidative stress, and DNA repair, further exacerbating the impact of air pollutants on male fertility.
The study emphasizes the clinical implications of these findings. Excessive ROS production due to air pollutants can overwhelm the body’s antioxidant defenses, leading to oxidative stress and subsequent damage to sperm cells. The team calls for increased awareness and measures to reduce exposure to air pollutants, particularly in vulnerable populations. They suggest that public health policies should prioritize the reduction of air pollution to mitigate its impact on male reproductive health.
In conclusion, the research by Dr. Omolaoye and her colleagues provides compelling evidence of the adverse effects of air pollution on male reproductive health. By elucidating the mechanisms involved, particularly the role of oxidative stress, this study underscores the urgent need for interventions to protect and improve reproductive health in the face of rising air pollution levels.
Journal Reference
Omolaoye, T.S.; Skosana, B.T.; Ferguson, L.M.; Ramsunder, Y.; Ayad, B.M.; Du Plessis, S.S. (2024). “Implications of Exposure to Air Pollution on Male Reproduction: The Role of Oxidative Stress.” Antioxidants. DOI: https://doi.org/10.3390/antiox13010064
About the Authors
Dr Temidayo Omolaoye is an Assistant Professor of Physiology at the Mohommed Bin Rashid University of Medicine and Health Sciences, Dubai, UAE. She is passionate about research, and believes that the continuous dissemination of the knowledge acquired through this means is paramount. She is a recipient of various awards, scholarships, and research grants. Her core research interest includes reproductive medicine/physiology, endocrinology, diabetes, and reproductive toxicology. Currently, she focuses on the molecular mechanisms in diabetes-induced male infertility, employing the omics techniques. She also serves as an ad hoc reviewer for multiple reputable accredited journals.
Professor Stefan du Plessis is the Dean of Research and Graduate Studies at Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, UAE. His research interests are in the field of male reproductive physiology, resulting in more than 133 peer-reviewed articles and nearly 5500 citations. He also has to his credit 30 book chapters and 4 books and has supervised numerous Doctoral and Master’s students. He serves on the editorial board of two international journals and acts as an ad hoc reviewer for various funding bodies and scientific journals. Prof du Plessis has recently been elected as member of the Mohammed bin Rashed Academy of Scientists (MBRAS), is a National Research Foundation B-rated researcher and the recipient of a Fulbright Scholarship as well as several other research and teaching awards.
Lisa Marie Ferguson received her MSc degree from Stellenbosch University (SU) in 2021 and is currently in her final year of doctoral studies at the Stellenbosch University Reproductive Research Group (SURRG), housed within the Biomedical Research Institute (BMRI) at SU in Cape Town, South Africa. Her research interests are centred around exploring the various elements that influence the functionality of spermatozoa, with a particular emphasis on the molecular underpinnings that lead to sperm dysfunction. Her work contributes to a broader understanding of male fertility issues.
Yashthi Ramsunder is a current PhD candidate specializing in the field of andrology research at the Stellenbosch University Reproductive Research Group (SURRG), a lab within the Biomedical Research Institute at Stellenbosch University in Cape Town, South Africa. After completing her masters in 2023, her research focuses on the impact of drug-based therapies and lifestyle factors on male fertility parameters. Additionally, she has conducted extensive research on the molecular framework underlying spermatozoa function. Outside of work, Yashthi is an avid baker and an active member of the physiology research communities, frequently speaking at conferences and mentoring aspiring physiology researchers.
Bashir Mohammed Ayad is currently the Head of the Department of Physiology and Assistant Professor of Medical Physiology at the Faculty of Medicine, University of Misurata, Libya. He graduated with a BSc (1998), MSc (2009) and PhD (2018) degrees. He has supervised and examined many graduate and doctoral students. His research interests are in the areas of cell physiology, andrology, endocrinology, respiratory physiology, DNA fragmentation and oxidative stress. He has actively collaborated with other renowned scientists from around the world, notably Professor Stefan Du Plessis (Dean of Research and Graduate Studies, Professor of Physiology, Dubai Medical College (MBRU), UAE) and other internationally renowned scientists. He has published numerous peer-reviewed scientific articles and book chapters. He has been a regular ad hoc reviewer for a number of national and international scientific journals. aydbm74@gmail.com
