Are Sperm Counts Really Declining?
Scientific AmericanDec 23, 2022
The Facts
A review of 25 studies spanning nearly 50 years has linked exposure to two widely used classes of insecticides — organophosphates and N-methyl carbamates — to lower sperm concentration in adult men worldwide.
The study, published in the journal Environmental Health Perspectives on Wednesday, has found that men who worked in industries like construction and agriculture had significantly lower sperm concentration than their counterparts employed in other sectors.
The Spin
Narrative A
Scientists have obtained solid evidence of widespread declining sperm counts for decades — first, a 1992 study found overall sperm count dropping 50% over the previous 60 years, and then a 2019 study found that moving sperm declined 10% over the previous 16 years. These numbers should concern everyone and prompt both voters and their governments to take a stand against the use of chemicals that cause infertility.
Narrative B
While some studies, though certainly not all, have shown that sperm count is dropping, none have been able to conclusively demonstrate a deterioration of sperm quality. It's also important to recognize that many factors could be contributing to declining sperm concentrations, including whether they're immobilized before they're counted. Alongside pesticides, obesity rates, and rising temperatures may also be playing a role. This issue needs more analysis before the world begins to fixate on a single cause and, therefore, solution.
Metaculus Prediction
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