In 1930, there would be 130 million sperm cells per milliliter of semen but today the count has gone down to 15 million sperm cells in the same volume, a staggering 88.5 per cent drop. The major factors contributing to such a horrendous drop can be summarized as the following;
Man's sperm count has decreased by 89% in less than 100 years due to various factors such as lifestyle choices, exposure to manmade chemicals like phthalates found in plastics, obesity, lack of physical activity, and diets high in ultra-processed foods. Processed food contains high levels of estrogen, a hormone which opposes sperm production. Additionally, the conflict of sex chromosomes, known as the meiotic drive, may be inhibiting the production of sperm cells, contributing to the decline in sperm counts globally. These factors, along with age-related changes in sperm concentration, motility, morphology, and seminal volume, have collectively led to a significant decrease in sperm count over the past century. A lower sperm count can result in reduced fertility, making it harder for couples to conceive, potentially leading to longer times to achieve pregnancy. This delay in conception is particularly concerning as many individuals are delaying childbearing until later in life when fertility is already reduced. Declining sperm counts are not just a problem for individual couples but could have broader societal impacts, affecting the future workforce and demographic trends as fewer young people may be available for work and population growth may slow down. Overall, the decrease in sperm count is a serious issue that warrants attention and action to address potential threats to human reproduction and overall health.
Ref:
https://www.lemonde.fr/en/health/article/2022/11/15/a-threat-to-human-survival-decreasing-sperm-count-is-a-global-problem-study-finds_6004350_14.html 
