A 2022 meta-analysis found that sperm counts (the number of sperm per ejaculate) in humans have been dropping at an increasing rate in recent decades, reports National Geographic. A 2017 study found that sperm counts had "plummeted by more than 50 percent among men in North America, Europe, Australia, and New Zealand between 1973 and 2011." The newer study found that "not only has the decline in total sperm counts continued — reaching a drop of 62 percent — but the decline per year has doubled since 2000."
Shanna Swan, a reproductive and environmental epidemiologist at the Icahn School of Medicine at Mount Sinai in New York City, says the plummeting sperm counts could be attributed to multi-generational exposure to environmental chemicals.
