Numbers count, especially when it comes to sperm. And in the case of men’s fertility, the primary measures of sperm health—volume, concentration, motility, and morphology—have all been adversely affected in men around the world over the past four decades. While one single cause of reproductive issues hasn’t been pinpointed, a growing body of research ties exposure to environmental pollutants and toxins (1). The evidence is also starting to suggest that Black men’s sperm quality may be affected the most.
Researchers at top universities, health-related organizations, and government entities alike agree: Low-income and non-white Americans have far greater exposure to environmental hazards that impact sperm health.
It’s thought this is due to discriminatory laws and policies related to housing and the construction and regulation of factories, landfills, pipelines, power plants, and other sources of pollution—a phenomenon known as environmental racism.
Systemic effects of this exposure can be seen throughout the body, from the immune and endocrine systems to the respiratory and reproductive systems, says Carmen Messerlian, Ph.D., assistant professor of environmental reproductive, perinatal, and pediatric epidemiology at Harvard T.H. Chan School of Public Health.
And research shows Black men’s sperm quality seems to be particularly affected by exposure to environmental hazards.
Here’s what we know—and what can be done to fix the problem.
What Environmental Factors Affect Sperm Quality?
When we hear the term “environment,” we tend to think of nature and the outdoors. But Messerlian says there are actually three parts of everyone’s “total” environment.
The natural environment includes, of course, the air you breathe, the water you drink, and the food you eat. But there’s also your social environment: your family and community structures, and exposures to stress and trauma from childhood into adulthood.
The ‘built environment’ is the third. That’s anything that’s manufactured: buildings such as your home, school, church, and workplace, as well as your shoes, clothing, car, and gadgets. All three intersect and intertwine throughout a person’s life and impact their overall health, Messerlian says.
A lifetime of exposure to toxins—in air, water, food, personal-care products, and more—combined with various internal and external stressors can have a compounding effect in the body, Messerlian says.
Internal stressors include how you regulate stress physiologically, she says (2). “External ones are exposure to racism, social and cultural impacts, and environmental conditions,” Messerlian adds.
Everyone’s social and built environments are different and individualized.
But here’s what we know about common factors in the natural environment that research suggests can disproportionately affect Black Americans.
It’s an unfortunate part of global society. And your health can depend on where you live, particularly for non-white Americans.
Decades of past federal housing discrimination continue to impact the health of Black Americans and other people of color—despite the practice being outlawed in the late 1960s, according to research published in 2022 (3).
Here’s what went down: During the Depression, more than 200 U.S. metropolitan areas were graded from A to D based on their “desirability.” Neighborhoods that received the worst D grade (or which were “redlined” with a literal red line around them on a map) tended to have large populations of Blacks and immigrants and/or were close to known sources of environmental pollution.
Residents of D-grade communities were often unable to secure federally backed home loans or favorable mortgage terms, which forced them to live near D neighborhoods, according to the same 2022 research. In fact, the report revealed data from formerly redlined U.S. cities, and found “communities of color in the United States are systematically exposed to higher levels of air pollution.”
“For those who live near polluting industries, such as plastic-manufacturing plants or oil and gas facilities, they can have higher exposures from these sources,” explains Tracey J. Woodruff, Ph.D., MPH, professor and director of the Program on Reproductive Health and the Environment at the University of California, San Francisco. “So Black communities can have higher exposures to a number of different chemicals.”
The 2022 study found higher concentrations of nitrogen dioxide and fine particulate matter associated with redlined neighborhoods. Research has also shown that common pollutants can have negative effects on both male and female reproductive health—including sperm quality (4).
In men, those contaminants, plus others (such as ozone and carbon monoxide), have been associated with decreased sperm volume, concentration, motility, and normal morphology (4).
There’s more. Endocrine disruptors can mimic hormones and both repress androgen production (including testosterone) and behave like estrogen. Known endocrine-disrupting chemicals include phthalates, bisphenol A (BPA), phenol, and per- and polyfluorinated chemicals (PFAS).
PFAS are found virtually everywhere, too: in clothing, food packaging, sparkling water, furniture, nonstick cookware, and tons of other everyday products. The factories that make these and other products may also release PFAS into the air and water, and the chemicals can accumulate in animals and fish.
Woodruff says phthalates and other chemicals are found in lots of common goods, including personal-care products. “Research has found higher levels of these harmful chemicals in some products marketed to people of color,” she says.
It’s not just the cool music from the 80’s. Some studies have associated heavy metal exposure with a negative impact on male fertility, including sperm quality (6). One study found sperm concentrations were lower in male children of women who’d been exposed to heavy metals while pregnant. Other research has found a link to reduced sperm quality in men who’ve been exposed to lead, cadmium, barium, and other heavy metals (4).
In terms of the sperm quality crisis in Black men? Research has found poverty and race can be tied to exposure to heavy metals such as arsenic, copper, zinc, mercury, and cadmium, with elevated concentrations often found in predominantly low-income and minority communities (7, 8). Often byproducts from industrial, agricultural and other industries, heavy metals can pollute the air as fine particulate matter or contaminate soil and water.
What Can Be Done to Improve Sperm Quality in Black Men?
To start, Messerlian says, more research needs to be done on men’s reproductive health—specifically, Black men’s reproductive health. There isn’t enough data, and research suggests Black men already face greater health and healthcare disparities (9).
In 2022, Messerlian and other researchers co-authored an article urging healthcare organizations and workers to take a more proactive approach to fighting climate change to help diminish its impact on reproduction and fertility—for both men and women (10).
According to Messerlian, investments in “green” manufacturing of food, products, and packaging that don’t use PFAS and other endocrine-disrupting chemicals that also contribute to air and water contamination could help.
Until then, she says, it’s up to consumers to try to limit exposure via small lifestyle choices.
Here are a few of Messerlian’s recommendations to help boost sperm quality and keep yourself healthy:
- Avoid packaged and processed foods as much as possible, as they tend to be housed in plastic. Lots of canned items are also lined with bisphenols, according to the Natural Resources Defense Council, so choose products marked as coming in BPA-free cans or boxes. You can also remove and store items in non-plastic containers as quickly as possible.
- Choose non-toxic household and personal-care products. The Campaign for Safe Cosmetics has compiled a list of Black-owned brands, including Jim + Henry, the Afro Hair & Skin Co., and EleVen by Venus Williams, among others.
- Cook in cast iron or stainless steel instead of nonstick pans. Many nonstick pans are coated with PFAS, which can break down at high temps and get into food. Or choose a PFAS-free brand, like Caraway Cooking.
- Reheat food in glass or microwave-safe cookware, not plastic or Styrofoam. The chemicals in plastic and Styrofoam can leach into food when heated.
- Purify drinking water with a NSF-certified, activated carbon or reverse-osmosis filter to remove chemicals and heavy metals. (The NSF certification helps ensure heavy metal removal.)
“Anything in the direction of less exposure to pollutants, even if it’s one percent, five percent, or 10 percent, is a win,” Messerlian says.