https://scienceblog.com/495382/comprehen...stern-men/
EXCERPT: In the first systematic review and meta-analysis of trends in sperm count, researchers [...] report a significant decline in sperm concentration and total sperm count among men from Western countries. [...] the researchers found a 52.4 percent decline in sperm concentration, and a 59.3 percent decline in total sperm count, among men from North America, Europe, Australia and New Zealand who were not selected based on their fertility status. In contrast, no significant decline was seen in South America, Asia and Africa, where far fewer studies have been conducted...
EXCERPT: In the first systematic review and meta-analysis of trends in sperm count, researchers [...] report a significant decline in sperm concentration and total sperm count among men from Western countries. [...] the researchers found a 52.4 percent decline in sperm concentration, and a 59.3 percent decline in total sperm count, among men from North America, Europe, Australia and New Zealand who were not selected based on their fertility status. In contrast, no significant decline was seen in South America, Asia and Africa, where far fewer studies have been conducted...