Disruptors on Male Reproduction – Emerging Risk Factors

Couple infertility represents a significant public issue affecting childbearing-aged couples’ health, financial, psychological, and social aspects and many more. As reported by the World Health Organization, the number of infertile couples was 48 million in 2010;[1] thus, the current prevalence is assumed to be higher. In approximately half of these couples, a male infertility factor is identified, consistently with the presence of abnormal sperm parameters, such as abnormal number, motility, and/or morphology.[1] Epidemiological data indicate an increase in the prevalence of male infertility globally. The latest meta-regression analysis examining the sperm parameters of healthy subjects worldwide reported that sperm concentration and total sperm count have halved in the past 40 years, with a higher slope after the 2000s.[2] There is no apparent explanation for this evidence. Although some hypotheses have been suggested, no cause–effect relationship has been demonstrated so far. In addition, some authors suggest that, despite a comprehensive diagnostic workup, apparent explanation for male infertility in up to 70% of cases may be obscured.[3,4] Furthermore, considering the association between poor sperm quality and the greater risk of hospitalization, diabetes, cardiovascular disease, morbidity, mortality,[5,6] and cancer,[7] the urgent need for better understanding of the etiology of male infertility is of high importance. The health of male reproductive organs is vital for human reproduction and maintaining a sustainable population. However, the impact of modern lifestyles and environmental factors on male reproductive function has raised concerns about the negative effects of various disruptors. It is crucial to comprehend these emerging risk factors to prevent and address male reproductive disorders.[8] Environmental contaminants known as endocrine-disrupting chemicals (EDCs) interfere with hormone signaling and disrupt endocrine function. EDC exposure has been linked to hormone imbalances, altered sperm quality, and reduced fertility in males. Heavy metal pollutants such as lead, cadmium, and mercury also have reproductive toxicity and can impair sperm function and hormone regulation, leading to infertility[9] Ionizing radiations: Sperm cells are greatly endangered by prolonged exposure to medical imaging, occupational exposures (such as X-rays and gamma rays) and environmental sources. These can result in a significant decline in fertility and an increased likelihood of genetic abnormalities[10] Pesticides and herbicides: Agricultural chemicals such as pesticides and herbicides have endocrine-disrupting properties that can negatively impact male fertility through altered hormone levels and sperm abnormalities[11] Pharmaceuticals: Certain medications, including antidepressants and antiandrogens, may interfere with hormone signaling and spermatogenesis, influencing male fertility[12] Plastics and microplastics: Chemicals used in plastic production and microplastics found in the environment have been linked to endocrine disruption and adverse effects on male reproductive health. Disruptors can affect male reproduction through various mechanisms, including hormone disruption, oxidative stress, epigenetic modifications, and DNA damage.[13] Many studies have looked at the link between disruptors and male reproductive health. These studies provide important information about the risks and potential effects on fertility. To reduce exposure to disruptors, effective mitigation strategies can involve legislative actions, raising public awareness, and using safer alternatives. The evidence presented in this review indicates that various disruptors can pose significant risks to male reproductive health. Understanding their mechanisms of action and implementing effective mitigation strategies are crucial to safeguarding male fertility and reproductive outcomes. Finally, research is urgently needed to understand the etiology of apparently idiopathic forms of male infertility and the decline in sperm counts.