Scientists warn plunging sperm counts could lead to human extinction

A team of scientists is sounding the alarm about declining sperm counts among men in the Western world.

As Hagai Levine, the lead author of a recently published study, told the BBC, "If we will not change the ways that we are living and the environment and the chemicals that we are exposed to, I am very worried about what will happen in the future."

He added, "Eventually we may have a problem, and with reproduction in general, and it may be the extinction of the human species."

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For the research, he and his team conducted a meta-analysis of previous studies and found that "sperm counts...declined significantly among men from North America, Europe and Australia during 1973–2011, with a 50–60% decline among men unselected by fertility, with no evidence of a 'leveling off' in recent years."

The paper goes on to state that "These findings strongly suggest a significant decline in male reproductive health, which has serious implications beyond fertility concerns."

While the team did not investigate the exact causes of the downward trend, they write that "sperm count has been plausibly associated with multiple environmental and lifestyle influences, both prenatally and in adult life."

Specifically, they note, "endocrine disruption from chemical exposures or maternal smoking during critical windows of male reproductive development may play a role in prenatal life, while lifestyle changes and exposure to pesticides may play a role in adult life."

As such, they call sperm count decline a "'canary in the coal mine' for male health across the lifespan."

The team hopes its work will spur other scientists and organizations to identify causes behind the decline in order to pursue preventative measures.