Shanna Swan is a professor of environmental medicine and public health at Mount Sinai school of medicine in New York City, studying fertility trends. In 2017 she documented how average sperm counts among western men have more than halved in the past 40 years.
"People are recognising we have a reproductive health crisis, but they say it’s because of delayed childbearing, choice or lifestyle – it can’t be chemical. I want people to recognise it can. I am not saying other factors aren’t involved. But I am saying chemicals play a major causal role. It is difficult to use that word, “cause”, but it’s a body of evidence. We have mechanisms, animal studies, and multiple human studies."
"If you follow the curve from the 2017 sperm-decline meta-analysis, it predicts that by 2045 we will have a median sperm count of zero. It is speculative to extrapolate, but there is also no evidence that it is tapering off. This means that most couples may have to use assisted reproduction."