Male Exposure to Chemicals Linked to Longer Time to Conceive

January 31, 2023

By Megan Boyle, Editorial Director

It’s well known that what a woman eats, drinks, breathes and puts on her body while she’s pregnant or nursing can all affect her reproductive system and the health of her baby. But new research reveals that a man’s exposure to harmful chemicals plays an important role, too.

A recent study found that the concentration of heavy metals, persistent organic pollutants and phthalates in a man’s body had more effect on how long it took a couple to conceive than the concentrations of those chemicals in the woman.

The researchers looked at data from the Longitudinal Investigation of Fertility and the Environment (LIFE) Study at the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The study explored the relationship between environmental chemicals and fertility by following 501 couples for up to a year while they tried to conceive, tracking such factors as time-to-pregnancy, miscarriages, infertility, birth size and more. 

The research, led by the Institute’s Germaine Buck Louis and published in the January edition of the journal Andrology, measured the amounts of certain chemicals in the urine and blood samples of both partners. Male exposures were associated with as much as 30 percent reduction in “couple fecundity,” as measured by the amount of time it took them to conceive.

Most problematic were the men’s exposure to lead, benzophenones, PCBs and some phthalates – a finding supported by earlier laboratory and observational studies that found that men with greater exposures to environmental contaminants have poorer sperm quality. Only two of the 86 chemicals studied – both PCBs – negatively affected the reproductive systems of both sexes.

Each of the couples in the LIFE study eventually became pregnant, and for many, the road to conception can be long, paved with a variety of obstacles such as family history, parental age and even stress. The study’s findings emphasize the importance of helping both parents – not just the mom – avoid harmful chemicals that can stymie healthy fertility and pregnancies. Here are some easy tips for potential moms and dads to avoid the common chemicals identified in the study:

• Lead gets into our bodies from drinking water, paint, cosmetics, toys and other sources. It is unsafe at any level, especially for fetuses and children. To avoid it, filter your water and check your home for old paint.
• Phthalates – industrial chemicals used in plastics, solvents and artificial fragrances – are linked to male reproductive problems and birth defects. To avoid them, don’t store or microwave food in plastic, choose wooden toys for your kids and skip products with artificial fragrance. EWG’s Skin Deep Cosmetics Database and EWG’s Guide to Healthy Cleaning can help you find safer products.
• PCBs – considered probable human carcinogens by the Environmental Protection Agency – are all around us as a result of widespread use in manufacturing from the 1930s until they were banned in 1976. Today we’re exposed to PCBs mostly through food, especially the fatty issues of meat. To avoid them, cut back on red meat, trim away fat from meat and fish and choose fresh or wild-caught salmon rather than farmed.

For more information about how to avoid chemicals that can disrupt your hormones, check out EWG’s Dirty Dozen List of Endocrine Disruptors.