Sperm counts have been on the decline for years and new research shows the problem is getting worse

Must read

Joe Biden pays tribute to victims of California mass shootings: ‘As a nation, we have to be there for them’

 President Joe Biden led a moment of silence at the White House on Thursday in honor of the victims of separate shootings that killed 11 people...

FDA pushes to make COVID-19 vaccinations easier. At the top of the list: One annual booster instead of two

The U.S. is poised to make COVID-19 vaccinations more like a yearly flu shot, a major shift in strategy despite a long list of...

Hasbro to cut 1,000 jobs as the pandemic-era toy-buying boom cools now that kids are back in school

Hasbro, one of the world’s largest toymakers, said it would cut 15% of its workforce, or about 1,000 jobs, after a disappointing holiday shopping...

A chemical plant’s polluting poisoned a generation of children in a small town. The settlement that the state just made has residents up in...

In hindsight, it’s clear that something was very wrong in this suburban town at the Jersey Shore, where many people worked at or lived...

Two key measures linked to male fertility—sperm count and concentration—have declined sharply in recent years, according to a new study, raising fears about future population growth. 

From 1973 to 2018, sperm concentration globally declined by more than half, according to a new analysis by an international team of researchers, published in the Human Reproduction Update journal on Tuesday. Meanwhile, total sperm counts declined 62.3% during the same period.

“Overall, we’re seeing a significant worldwide decline in sperm counts of over 50% in the past 46 years, a decline that has accelerated in recent years,” the lead researcher and professor at the Hebrew University of Jerusalem’s Hadassah Braun School of Public Health, Hagai Levine, said in a statement

A 2017 paper, from the same researchers, found that a decline in sperm counts was accelerating in North America, Europe, Australia, and New Zealand based on samples collected between 1973 and 2011.  

The more recent study, to build on previous findings, looked at South America, Asia, and Africa to understand the decline in sperm counts across the world. Using samples from over 57,000 men across 53 countries, combined with statistics used in prior studies, researchers found that men in those regions have also experienced a significant decline in sperm count as those in the previous study. 

Researchers found that sperm concentration has fallen 1.16% each year since 1972. However, when researchers looked at data from after 2000, they found the annual decline was 2.64%.

“Our findings serve as a canary in a coal mine,” Levine said. “We have a serious problem on our hands that, if not mitigated, could threaten mankind’s survival. We urgently call for global action to promote healthier environments for all species and reduce exposures and behaviors that threaten our reproductive health.”

The analysis does not examine the causes behind the decline in sperm concentration and count, but Levine said that “lifestyle choices and chemicals in the environment are adversely affecting this fetal development.”

The study comes on the same day the world’s population hit 8 billion people, according to the UN’s estimate. But all signs point to a slowing of the overall population growth rate. It took 12 years for the world’s population to increase from 7 billion to 8 billion, but it’s expected to take another 15 years for it to reach 9 billion. 

Meanwhile, the UN says fertility has fallen in several countries in recent decades. And the “cumulative effect of lower fertility, if maintained over several decades, could be a more substantial deceleration of global population growth in the second half of the century,” the UN’s director of the population division said in a statement

In the analysis, researchers note that sperm count is an “imperfect proxy for fertility,” but sperm concentration and count are closely linked to fertility chances. 

“On a population level, the drop in mean [sperm concentration] from 104 to 49 million/ml that we report here implies a substantial increase in the proportion of men with delayed time to conception,” researchers wrote in the study. “Thus, [sperm concentration] provides the most stable and reliable measurement for comparisons within and among populations and over time.”

Sign up for the Fortune Features email list so you don’t miss our biggest features, exclusive interviews, and investigations.

More articles

Latest article

Joe Biden pays tribute to victims of California mass shootings: ‘As a nation, we have to be there for them’

 President Joe Biden led a moment of silence at the White House on Thursday in honor of the victims of separate shootings that killed 11 people...

FDA pushes to make COVID-19 vaccinations easier. At the top of the list: One annual booster instead of two

The U.S. is poised to make COVID-19 vaccinations more like a yearly flu shot, a major shift in strategy despite a long list of...

Hasbro to cut 1,000 jobs as the pandemic-era toy-buying boom cools now that kids are back in school

Hasbro, one of the world’s largest toymakers, said it would cut 15% of its workforce, or about 1,000 jobs, after a disappointing holiday shopping...

A chemical plant’s polluting poisoned a generation of children in a small town. The settlement that the state just made has residents up in...

In hindsight, it’s clear that something was very wrong in this suburban town at the Jersey Shore, where many people worked at or lived...

Health effects of cannabis products are too uncertain for regulating the fast-growing market like food or supplements, FDA says

The Food and Drug Administration said Thursday there are too many unknowns about CBD products to regulate them as foods or supplements under the...