The role of physical agents' exposure in male infertility: A critical review

Background: A decrease in semen quality is an increasingly widespread pathological condition worldwide. Jobs and lifestyles have changed a lot with the advancement of technology in the last few decades, and a new series of risk factors for male infertility have spread. Objective: This review aims to summarize the current literature on this relationship, evaluating alterations in semen parameters and hormonal profile. Methods: A deep research was performed through MEDLINE via PubMed, Scopus, and Web of Science on articles regarding the relationship between physical agents and male fertility over the last twenty years. Some physical agents already associated with male infertility, such as heat and radiation, while emerging ones, such as physical exertion, psychological stress and sedentary activities, were newly considered. Results: Most studies described sperm quality after exposure. Overall sperm impairment was shown after radiation and alteration of specific parameters, such as sperm concentration, were observed after psychological stress and sedentary work. In addition, an association was also reported between physical exertion and hormonal profile, especially pituitary hormones and testosterone. Conclusions: Although the associations between physical agents and male infertility are suggestive, the level of evidence of the studies is not adequate to define their influence, except for physical exertion. Therefore, new prospective studies are necessary for the validation of the correlation and the possible safeguarding of the exposed working classes.