If you've heard sperm counts are declining, you're not imagining things. A major 2017 study led by Dr. Hagai Levine and co-authored by Dr. Shanna Swan found that sperm counts in Western men dropped by over 50% between 1973 and 2011. That's more than a 1% decline per year—and the trend continues. Dr. Swan, a leading reproductive epidemiologist and author of Count Down, points to endocrine-disrupting chemicals (EDCs) like BPA and phthalates, along with lifestyle factors, as key culprits behind this fertility crisis. While in the 1940s–70s, 60–100 million sperm/mL was typical, today's "normal" according to the World Health Organization is just 15 million/mL. The good news? Simple daily habits can help protect your fertility without overhauling your entire lifestyle.