The size of the human penis is historically shrinking, and a scientist is claiming pollution is responsible for the problem that may eventually threaten the population in the future.

Dr. Shanna Swan, a professor in environmental medicine and public health at Mount Sinai Hospital in New York City, released the book “Count Down” claiming her research has found that more babies are being born with small penises, Sky News reports.

Swan stated the “existential crisis” will impact fertility rates as both males and females are being born with malformed genitalia due to plastic by-products known as phthalates.

The professor explained humans can be exposed to phthalates through toys and some foods. When humans are exposed to these harmful chemicals, which are used in manufacturing plastics, it can cause issues with the hormone production in the endocrine system.

Since phthalates are similar to the hormone estrogen, they can affect natural hormone production.  Researchers were able to link the chemical to hindering sexual development in infants and behaviors in adults.

“Count Down” explores “how our modern world is threatening sperm counts, altering male and female reproductive development, and imperiling the future of the human race.”

However, Swan’s research found humans may not be the only victims dealing with fertility issues because of pollution. The scientist claimed the same results were observed in rat fetuses exposed to phthalates, TMZ reports.

With the historically smaller size of the male penis on the rise, Swan claims if nothing is done to remedy the issue, most men won’t be unable to produce viable sperm by 2045.

However, the professor isn’t the first to raise concerns about fertility issues plaguing the human race. In 2017, a study observing 45,000 healthy men over four decades found sperm levels have dropped by more than 50% in western countries.

Analysts predict that the total market in China for fertility services will reach $1.5 billion in 2022 -- more than double its 2016 value Analysts predict that the total market in China for fertility services will reach $1.5 billion in 2022 -- more than double its 2016 value Photo: AFP / NOEL CELIS