New York based epidemiologist Shanna Swan says that falling sperm counts are a threat to human survival in her new book, “Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperilling the Future of the Human Race.”
Dr. Swann is an environmental and reproductive epidemiologist at Icahn School of Medicine at Mount Sinai in New York. She led the 2017 study that revealed that sperm counts around the world have fallen by more than half since the early 1970’s. https://choice.npr.org/index.html?origin=https://www.npr.org/2017/07/31/539517210/sperm-counts-plummet-in-western-men-study-finds
In her new book, Swan claims that sperm counts are declining rapidly, so much so that by 2050, most people will need technological assistance to have children. There are many environmental factors causing infertility. Swan believes that household chemicals called phthalates are a big problem.
Phthalates are found in lots of products. They make plastics pliable, they make it possible for our skin to absorb lotion and they are found in food packaging like cellophane. They’re also to be found in vinyl flooring, detergents, lubricating oils, automotive plastics, plastic clothes (raincoats), soaps, shampoos, hair sprays, and nail polishes).
However they can leak into our food and into our bodies where they can disrupt the endocrine system that controls hormones, including testosterone. Swan believes that this is a primary factor in male infertility. 
Shanna Swan has given several interviews to UK newspapers to promote her book. As far as I can tell, nobody has asked her about cell phones, laptops, WIFI and microwave ovens. I don’t know her and I am not an epidemiologist, but no credible examination of the causes of male infertility can ignore the impact of non-ionising radiation.
Last October, Pooja Negi and Rajeev Singh from the Department of Environmental Studies at The University of Delhi, published a review entitled: “Association between reproductive health and nonionizing radiation exposure.” The researchers found that:
Male infertility is likely to be affected by the strong exposure to heat and radiations. The most common sources of nonionizing radiations are cell phones, laptops, Wi-Fi and microwave ovens, which may participate to the cause of male infertility. One of the major sources of daily exposure to non-ionizing radiation is mobile phones.
A mobile phone is now basically dominating our daily life through better services such as connectivity, smartphone devices. However, the health consequences are linked with their usage are frequently ignored. Constant exposure to non-ionizing radiations produced from a cell phone is one of the possible reasons for growing male infertility.
Recently, several studies have shown that cell phone users have altered sperm parameters causing declining reproductive health. Cell phone radiation harms male fertility by affecting the different parameters like sperm motility, sperm count, sperm morphology, semen concentration, morphometric abnormalities, increased oxidative stress along with some hormonal changes.
https://www.tandfonline.com/doi/abs/10.1080/15368378.2021.1874973?journalCode=iebm20
As the researchers say, the health consequences of smartphone connectivity are frequently ignored. Scientists who have taken it on in the past have been attacked and discredited, most notably Dr. Christopher Busby, who has appeared on The Riche Allen Show.
I’ve no doubt that we are exposed to harmful chemicals every hour of every day. They’re in our food, in our clothes and our cleaning products and I’m sure they don’t do fertility any favours. But when it comes to male fertility the smart money (pun intended) is on mobile phones, wi-fi, laptops, tablets and microwave ovens. But Western academics don’t want to go there.
