The quality of Western men’s sperm cells has deteriorated fast in recent decades. The cause? Pesticides. At least that’s what Gert Dohle, urologist at the Erasmus MC hospital in the Netherlands, says. It’s not tight underpants or Wi-Fi and other microwaves that are causing the spermatozoa a headache. Not even smoking or drinking are the main causes, according to Dohle. “Our tap water contains all sorts of pesticides that suppliers of drinking water can’t filter out. These substances amass in the fat tissue of pregnant women, ending up in the fetus through the placenta. As a result, the testicles’ development is hampered.” While 20 years ago the average man still had 60 million sperm cells per milliliter, the count now is just 40 million. If the trend continues, there will only be 20 million 20 years from now, and that would substantially lower the chance of natural fertilization, Dohle says.