In a study published in January 2024 in the journal Antioxidants, researchers established a link between air pollution and male fertility potential. Air pollution, originating from both indoor and outdoor sources, has long been regarded as an environmental health hazard. However, its impact is still being discovered, with multiple studies showing that the detrimental effects of air pollution extend far beyond respiratory and cardiovascular disease, and well into male reproductive health.
Air pollution is a global health issue
Around 2.4 billion people are exposed to hazardous levels of indoor pollution, while over 99% of the global population breathes air containing pollutants that exceed World Health Organization (WHO) guideline limits. Given its widespread presence and detrimental effects on human health, it is unsurprising that air pollution is the world’s leading environmental cause of diseases.
At the same time, multiple studies have highlighted a worldwide decline in semen quality indicators. A study by Carlsen et al. revealed a 50% decrease in sperm count between 1940 and 1990. Similarly, Levine et al. reported a significant decline in global sperm concentration between 1973 and 2011 (0.70 million/mL/year).
How does air pollution impair fertility?
The researchers of this study note that air pollutants, upon entering the body through inhalation, percutaneous contact, or ingestion, trigger the production of reactive oxygen species (ROS), highly reactive molecules that can damage cellular components. The resulting oxidative stress disrupts various physiological processes, including sperm production and function.
Exposure to air pollutants impairs male fertility in multiple ways:
Reduced sperm parameters
Air pollutants can lower semen volume, sperm concentration, total and progressive motility, and morphology, directly affecting reproductive potential. Studies reviewed show that seasonality plays a role in the concentration of air pollutants: sperm motility and kinematic parameters were significantly reduced during spring and autumn. Additionally, the longer the exposure, the higher the effect. The adverse effects of exposure affect not only the reproductive potential of the immediate generation but also the male children of those affected.
Exposure to air pollution can damage sperm DNA, leading to DNA fragmentation and aneuploidy. This can increase the risk of infertility, birth defects, and prenatal mortality. Air pollution can also alter the expression and function of genes in various tissues and organs, including the testes. This can lead to epigenetic modifications, mutations in blood cells and sperm cells, and telomere shortening. These effects can have a negative impact, both on reproductive health and overall health.
Air pollutants can trigger an inflammatory response in the testes, further impacting sperm production and function.
The decline in sperm quality and quantity not only contributes to the rising prevalence of male infertility but also presents a socioeconomic burden, significantly impacting healthcare costs.
Testing for pollutants
Fertility professionals can play a crucial role in addressing the connection between air pollution and male fertility by educating patients, encouraging them to adopt preventive measures, and promoting healthy lifestyle changes. The measurement of advanced semen parameters, such as sperm DNA fragmentation, genetic/genome tests, ROS and oxidative stress, acrosome reaction, and sperm chromatin can help identify if pollutants are of concern, especially in the diagnosis of unexplained male infertility. Learn more about the cutting-edge testing solutions available for your fertility clinic, including CE and FDA-approved Sperm Quality Analyzers (SQA), laboratory accessories, and at-home testing kits at mes-global.com.