While it might seem like most of the attention around infertility is focused on women, men are found to contribute to almost 50% of all cases of infertility.
Exposure to environmental toxins such as per- and polyfluoroalkyl substances (PFAS) has been suggested as a major contributing cause.
Recent research has shown that everyday toxins in the environment could be greatly impacting male fertility by reducing sperm quantity and quality, sending testosterone levels plummeting and having drastic effects on men's sex drive. Add to that, another possible cause for alarm: The same environmental toxins also could be disrupting the reproductive development of baby boys in the womb, resulting in smaller penises and testicles.
In a 2017 meta-analysis of 185 studies, Dr. Shanna Swan, a reproductive epidemiologist at Mount Sinai, and a team of researchers discovered a 50% decrease in male fertility rates from 1973-2010. They found that among nearly 43,000 men in North America, Europe, New Zealand and Australia, sperm counts decreased from 99 million sperm per milliliter of semen in 1973 to 47 million per milliliter in 2011.
The researchers estimate, on average, a man today is producing half the sperm as did his grandfather nearly 40 years ago.
Is there a link between plastics and male infertility?
So, what's changed since the 1970s that could account for this drastic decline in sperm production? Global plastics production has increased over 900%, and with it, our exposure to the chemicals used to make them.
Plastics contain chemicals that are toxic to humans. Called per- and polyfluoroalkyl substances (PFAS), these toxins are phthalates, BPA (bisphenol A) and other bisphenols. These chemicals are added to plastics during manufacturing to make them harder or softer, transparent, and durable. PFAS are literally everywhere and due to their strong chemical bonds, never fully break down, remaining in the environment and accumulating in people for decades. Found in an estimated 99% of all Americans, PFAS enter your body through what you eat, drink, touch and breathe.
There are many different toxins in our environment, but PFAS could be directly linked to male infertility.
PFAS are endocrine disruptors (EDCs) that can interfere with male reproductive function. When absorbed in the body, EDCs can decrease or increase normal hormone levels, mimic the body's natural hormones, or alter the natural production of hormones, resulting in lower sperm count and motility, lower amount and quality of semen, and potential adverse effects upon boy babies in the womb who need adequate testosterone levels for their development.
Importantly, the impact of EDCs is cumulative. And because PFAS have the potential to change the way genes are expressed, their impact on EDCs can be inherited. This means that it is possible for a father to pass along his low sperm count to a son, whose sperm count could drop even lower after being exposed to endocrine disruptors.
How to reduce PFAS exposure
While the Environmental Protection Agency (EPA) continues to expend extensive efforts to assess the potential impacts of PFAS on health and the environment, avoiding them whenever possible can only help to protect men and their fertility. Many products marketed to men contain PFAS—and they can exist everywhere from food to water bottles to store receipts. But you can begin to protect your partners and sons right now by reducing their exposure to limit the effect of the toxins in their surroundings. At first, the lists below may seem daunting, but making even one small change can have an impact.
How to reduce PFAS exposure in your home
- Test your water and install a filtration system on the main water supply to your home to remove potential toxins that have entered groundwater.
- Prevent dust buildup in your home that may contain traces of toxins.
- Avoid using adhesives, lubricants, paints, varnishes and paint strippers, car cleaning products, pesticides, spot removers and rug cleaning fluids, which can all emit highly toxic chemicals.
- Skip the air fresheners and heavily perfumed products, and avoid smoke, strong chemicals, plastic smells and fumes when noticed, and air out your home often to reduce the amount of inhalable chemical particles.
- Use 'green chemicals' in your garden which are made of non-toxic agents to reduce pests and weeds.
- Go green in your home as well and choose products that use alternative non-toxic agents to do the job. Household products like detergents, hand sanitizers, cleaning agents, and carpet cleaners, or strong chemicals like glues, paints, and varnishes, have numerous toxic chemicals in them.
How to limit PFAS exposure from food
- Grow more of your own produce or aim to buy organic and locally grown fruit, vegetables, dairy products and meats when possible to reduce your intake of pesticides, fungicides and herbicides.
- If you don't have access to organic produce, always wash it before eating to eliminate residual toxins.
- When possible, reduce your intake of processed, canned and pre-packaged foods to lower your exposure to compounds such as BPA, phthalates and plasticizers that often coat the inside of cans and those absorbed from plastic wrapping.
- Eat less oily fish (salmon, tuna, sardines) and fatty meats to reduce your consumption of pesticides, heavy metals and fat-soluble chemicals that can accumulate in your tissues and organs.
How to reduce PFAS exposure in food storage
- Limit the potential for plastics leaching into your food by avoiding those with the number "3" within the arrows and the letters "V" or "PVC" below the arrows—look for numbers 1, 2, 4 and 5 instead, as these are generally more stable.
- Drink from glass, stainless steel or hard plastic bottles—not soft plastic bottles—to avoid BPA, phthalates and other plasticizers used to make plastics in bottles clear and flexible.
- Store food in glass containers and heat with a paper towel on top to avoid phthalates, BPAs and dioxins that can easily be absorbed when heating food in plastic, especially in fatty foods.
- Avoid PTFE-based nonstick pans (like Teflon) and kitchen utensils, and opt for stainless steel or cast iron instead.
How to reduce PFAS exposure when shopping
- Always ask for sales receipts to be emailed or texted to reduce skin exposure to receipts' shiny BPA coating.
- Choose paraben-free shaving cream, shampoos, body washes without "PTFE" or "Fluoro" ingredients.
- Be wary of products advertised as BPA-free—they often have replacement chemicals that can be just as harmful.
- Do your research, especially when buying outdoor gear, and choose clothing that isn't labeled stain- or water- repellant.
Avoiding PFAS is good for both the papa and the mama
Limiting exposure to toxins before, during and after pregnancy can help mitigate their effects on baby boys before they are born. But mamas who are breastfeeding might worry if their breast milk contains toxins: There's no avoiding the fact that it does. However, researchers from Ohio State and Johns Hopkins University have shown that the toxic load in breast milk is far smaller than that in the air most people breathe inside their homes.
Additionally, the CDC and many other public health experts say that despite breast milk's vulnerability to chemical contamination, the benefits of breastfeeding—from nutrition, important enzymes and antibodies it supplies, to the mama and baby bonding it provides—far outweigh the risks.
Here's the good news
Men can take comfort in knowing that the WHO considers a healthy sperm count range to be between 15 and 250 million sperm per milliliter and finds anything above 40 million to be of minimal benefit to fertility.
And even though environmental toxins may be everywhere, there is evidence that once a pollutant is no longer in use, or once its use is heavily restricted, the human body burden of that pollutant declines.
Additionally, studies suggest that PFAS can be eliminated from your body through sweat. And eating antioxidants like foods rich in vitamin E and selenium can reverse reduction in sperm count and improve sperm quality.
It's easy to find information on helping women decrease their exposure to toxins in their food, makeup, and personal care—especially when trying to conceive or once pregnant. But it is just as important to educate men on their significance as well. Knowing where PFAS lurk is half the battle. Knowing ways to limit exposure is the other. Once you train your mind, finding and avoiding toxins becomes second nature.
Correction, September 13, 2021: An earlier version of this post did not account for the WHO's perspective on healthy sperm count. It has been updated.
Agarwal A, Mulgund A, Hamada A, Chyatte MR. A unique view on male infertility around the globe. Reprod Biol Endocrinol. 2015;13:37. doi:10.1186/s12958-015-0032-1
Awuchi CG. Impacts of plastic pollution on the sustainability of seafood value chain and human health. International Journal of Advanced Academic Research. 2019;5(11):46-138.
Chandra A, et al., Infertility and Impaired Fecundity in the United States, 1982–2010: Data From the National Survey of Family Growth. National Center for Health Statistics Reports, Number 67, August 14, 2013.
Crisp TM, Clegg ED, Cooper RL, Wood WP, Anderson DG, Baetcke KP, Hoffmann JL, Morrow MS, Rodier DJ, Schaeffer JE, Touart LW. Environmental endocrine disruption: an effects assessment and analysis. Environmental Health Perspectives. 1998 Feb;106(suppl 1):11-56. doi:10.1289/ehp.98106s111
EFSA Panel on Contaminants in the Food Chain (EFSA CONTAM Panel), Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, Hoogenboom L, Leblanc JC, Nebbia CS. Risk to human health related to the presence of perfluoroalkyl substances in food. EFSA Journal. 2020 Sep;18(9):e06223.
Jarow JP, Sharlip ID, Belker AM, Lipshultz LI, Sigman M, Thomas AJ, Schlegel PN, Howards SS, Nehra A, Damewood MD, Overstreet JW. Best practice policies for male infertility. The Journal of Urology. 2002 May;167(5):2138-44. doi.org/10.1016/S0015-0282(02)03105-9
Kashir J, Heindryckx B, Jones C, De Sutter P, Parrington J, Coward K. Oocyte activation, phospholipase C zeta and human infertility. Human Reproduction Update. 2010 Nov 1;16(6):690-703. doi:10.1093/humupd/dmq018
Levine H, Jørgensen N, Martino-Andrade A, Mendiola J, Weksler-Derri D, Mindlis I, Pinotti R, Swan SH. Temporal trends in sperm count: a systematic review and meta-regression analysis. Human Reproduction Update. 2017 Nov 1;23(6):646-59. doi:10.1093/humupd/dmx022
Manisalidis I, Stavropoulou E, Stavropoulos A, Bezirtzoglou E. Environmental and health impacts of air pollution: a review. Frontiers in Public Health. 2020 Feb 20;8:14. doi:10.3389/fpubh.2020.00014
Wong EW, Cheng CY. Impacts of environmental toxicants on male reproductive dysfunction. Trends in pharmacological sciences. 2011 May 1;32(5):290-9. doi:10.1016/j.tips.2011.01.001
Zheng G, Schreder E, Dempsey JC, Uding N, Chu V, Andres G, Sathyanarayana S, Salamova A. Per-and Polyfluoroalkyl Substances (PFAS) in Breast Milk: Concerning Trends for Current-Use PFAS. Environmental Science & Technology. 2021 Jun 1. doi:10.1021/acs.est.0c06978