On: Sperm counts are declining. Scientists have pinpointed the main causes

[jhallenworld]

If it's pollution, which pollution?

This study lists the likely suspects (scroll down for the table), but is not quantitative enough to show which have the highest impact.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7807371/

My guess: it's lead from gasoline- we've contaminated all top-soil with it. The effects are going to be around for a long time.

[reocha → jhallenworld]

This wouldn't make sense, lead content in blood has been falling from about 15ug/dl in the 1970s to 1-2ug/dl in 2007[1]

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1797860/