Study links ultraviolet filters to male fertility problems

The study, which was conducted by scientists at the National Institute of Health and the New York State Department of Health Wadsworth Center, looked into Bezophenone (BP)-type ultraviolet (UV) filters, which is a class of chemical that is thought to comprise about 29 commonly used chemicals.

One of the most common uses for this class of UV filter is to protect skin and hair from sun damage, which means it is formulated as part of a variety of sun care, daily use skin care, hair care and other personal care products.

Certain UV filters shown to cause hormone and endocrine disruption​

The study findings, which were published in the American Journal of Epidemiology, found that some of the chemicals from the UV filters were absorbed into the skin which led to evidence of interference with the body’s hormones and endocrine system.

According to the authors of the published study, they found that men with high exposure to UV filters BP-2 or 4OH-BP had a 30 percent reduction in fecundity, the biological ability to reproduce.

There is sufficient medical evidence to prove that lower fecundity levels can sometimes result in women taking longer to conceive.

Male fecundity levels come into question​

“In our study, male fecundity seems to be more susceptible to these chemicals than female fecundity. The women participants actually had greater exposure to the UV filters overall, but their exposure wasn’t associated with any significant pregnancy delays,” ​said Germaine Louis, Ph.D., director of the Division of Intramural Population Health Research at the Eunice Kennedy Shriver ​National Institute of Child Health and Human Development.

“Our next step is to figure out how these particular chemicals may be affecting couple fecundity or time to pregnancy—whether it’s by diminishing sperm quality or inhibiting reproduction some other way.”​

The research involved 501 couples from 16 counties in Michigan and Texas who were trying to conceive between the period 2005 and 2009 and who were not known to have fertility problems.

Study recorded time to get pregnant​

The scientists recorded how long it took for each couple to become pregnant, or not, during a one year period, during which time they assessed urine samples for levels of five selected UV filters known to cause endocrine disruption.

The data also took into consideration age, lifestyle habits and individual BMI.

The study specifically found that men with evidence of UV filter exposure that fell in to the top the 75th percentile were found to have diminished fertility, irrespective of their partners’ exposure to the UV filters.

Study questions benzophenone UV filters​

“The skin is the body’s largest organ, and how we care for our skin matters in more ways than one,”​ said Dr. Louis.

“Sunscreen is important for sun protection, and we definitely encourage people to continue using sunscreen to avoid skin cancer. But men who are concerned about fertility may be interested in other ways to reduce their exposure to benzophenone UV filters—whether by cutting back on other products that contain the UV filters or by washing after returning indoors.”​

However, the scientists behind the study have also stressed that there are some shortcomings with the findings to date, specifically that they tested single urine samples from participants to assess chemical exposure, but participants’ levels of exposure might have changed over the course of trying for pregnancy.

Likewise, there is also no data to specify exactly what type of personal care or sunscreen products the participants were using.