system
A chat on subreddit /r/NoStupidQuestions
human
Sperm counts and testosterone levels have been decreasing for decades.
gpt
Residues of agricultural, pharmaceutical, and industrial chemicals play a role in that, mimicking hormones in our bodies. Probably microplastics, too. 

They're in our food, in our water, the air we breathe, in the environment, there's no getting away from it no matter how healthily you're trying to live.