Why Pollution Is Causing Penises to Shrink—And What This Mean for Fertility

Some lifestyle and environment-based changes may be in order to reduce issues with fertility.

Environmental scientists have warned for years that pollution can impact all aspects of health and one important impact is on fertility.

The book, Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race, discusses pollution's relationship to fertility, including the following warning: Industrial chemicals are making penises shrink—and impacting fertility.

Shanna H. Swan, PhD, author of the book and professor of environmental medicine and public health at the Icahn School of Medicine at Mount Sinai in New York City, has worked for more than 25 years to try to understand the impact chemicals have on our environment and our health.

"I have been speaking to scientists and scientific organizations and publishing research about these environmental—and reproductive—health effects for many years," Swan said. "My goal with this book is to reach as many people as possible and bring their attention to the current crises in reproductive health as well as the chemicals in our environment and lifestyle factors that are driving these changes."

Here's what the science says, and why it matters.

What Is the Link Between Penis Size and Pollution?

The occurrence of penis shrinkage starts in the womb. "When a pregnant woman has higher body concentrations of chemicals like phthalates, which lower testosterone levels, the development of her baby boy's genitals is disturbed," Swan explained. "This results in what has been named the 'phthalate syndrome,' which includes smaller penis size."

Swan published data on this back in 2005. Her work, which appeared in the journal Environmental Health Perspectives, linked phthalates—man-made chemicals widely used in toys, detergents, nail polish, soaps, and more—to physical changes in young boys.

Another study also found similar results. Essentially, those born to mothers with higher concentrations of phthalates in their bodies were more likely to have a smaller penis size at their 12-month checkup and testicles that hadn't fully descended.

Are Penises Really Shrinking? Here's What the Science Says
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How Does Male Infertility Occur?

50% of infertility cases are due to male factors. Male infertility may arise from several factors such as:

  • Physical testicular problems
  • Genetic disorders
  • Hormone issues
  • Sperm duct blockages
  • High fever or mumps history
  • Lifestyle or environmental factors

However, penis size is not included in the list. Furthermore, there is a lack of strong evidence to indicate that penis size is directly connected to fertility.

How Does Exposure to Pollution Affect Fertility?

Still, other outcomes of pollutant exposure have been connected to an individual's level of fertility.

Researchers noted that exposure to phthalates has been associated with the reduction of semen quality concerning semen volume, sperm concentration, and total sperm counts—all of which can lead to infertility in male individuals.

Additionally, a 2022 study noted that bisphenol-A (BPA), another chemical compound, is associated with a decrease in sperm production as well as live sperm availability (known as sperm vitality).

Swan called the change in sperm counts and other negative measures of reproductive health "alarming," adding, "these changes are driven by a combination of poor lifestyle choices and the hundreds of chemicals that people are exposed to on a daily basis throughout the world."

"There is certainly a growing body of medical literature suggesting that there may be a decline in sperm counts over time," said Joshua A. Halpern, MD, assistant professor of urology at Northwestern University Feinberg School of Medicine in Illinois.

But the research isn't perfect, Dr. Halpern said, noting that it's "very difficult to look back and compare different groups of men over time."

In other words, more research is needed. "The studies certainly raise significant concern, but we need better research to determine what is really going on and why," Dr. Halpern explained.

Women's health specialist Jennifer Wider, MD said that this information is important to pay attention to. "This is a well-researched book written by a respected expert in the field—shedding light on the fact that chemicals in our environment can have a detrimental effect on reproduction and our hormones," Dr. Wider said.

How To Minimize Fertility Issues

Count Down specifically breaks down things you can personally do to reduce your exposure to hormone-altering chemicals and make lifestyle changes that will support healthy reproductive development.

Swap Out Plastic

Since phthalates and BPA can find their way into plastic products, consider other options for storage when it comes to food and drinks. Also, you'll want to consider phthalate-free and BPA-free products when available.

"One easy strategy is to swap out plastic food-storage containers and bottles in your kitchen for glass, ceramics, or metal ones," Swan said. "This will help reduce exposure to hormone-altering chemicals, which is not only important for pregnant women and couples planning a pregnancy, but for everyone because these chemical exposures can have long-term ripple effects on your health."

Dr. Wider recommended that you "pay attention" to what you're exposed to. "Phthalates, chemicals used in plastic production, and other endocrine-disrupting chemicals should be limited in everyday products, and we should all demand change from governing bodies and stronger policies to protect children, men, and women," Dr. Wider said.

Make Lifestyle Changes

If you're planning to have kids, you can also do other things to try to boost your fertility. "Most things that are good for overall health are also good for fertility," Dr. Halpern said, noting that the following are key:

"And while it may be difficult to avoid some of the toxins found in the products we use every day, people should try to stay away from clearly harmful exposures, such as cigarette smoking and noxious chemicals," Dr. Halpern added.

Other lifestyle changes that may help include adapting healthy sleep patterns and avoiding too much heat around the scrotal area.

A Quick Review

There is some research to suggest that exposure to phthalates and BPA may play a role in infertility. But more research needs to be done regarding this important topic.

If you're concerned about infertility, you can swap out plastic bottles and containers and make lifestyle changes, like eating a more well-balanced diet and exercising. Furthermore, seeing a male reproductive specialist for a workup can also be helpful.

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6 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Swan SH, Main KM, Liu F, et al. Decrease in anogenital distance among male infants with prenatal phthalate exposure [published correction appears in Environ Health Perspect. 2005 Sep;113(9):A583]. Environ Health Perspect. 2005;113(8):1056-1061. doi:10.1289/ehp.8100

  2. Bustamante-Montes LP, Hernández-Valero MA, Flores-Pimentel D, et al. Prenatal exposure to phthalates is associated with decreased anogenital distance and penile size in male newbornsJ Dev Orig Health Dis. 2013;4(4):300-306. doi:10.1017/S2040174413000172

  3. Fainberg J, Kashanian JA. Recent advances in understanding and managing male infertilityF1000Res. 2019;8:F1000 Faculty Rev-670. Published 2019 May 16. doi:10.12688/f1000research.17076.1

  4. National Library of Medicine. Male infertility.

  5. Kumar N, Singh AK. Impact of environmental factors on human semen quality and male fertility: a narrative review. Environ Sci Eur. 2022;34(1):6. doi:10.1186/s12302-021-00585-w

  6. Virant-Klun I, Imamovic-Kumalic S, Pinter B. From oxidative stress to male infertility: review of the associations of endocrine-disrupting chemicals (Bisphenols, phthalates, and parabens) with human semen qualityAntioxidants. 2022;11(8):1617. doi:10.3390/antiox11081617

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