Sunblock may cause fertility problems

A chemical in sunscreen may cause fertility problems in men, a new study shows.

• Study: Men with UV blocking products in their system had fertility challenges


• There is no law mandating a product disclose it has this chemical in it


• Be sure to wash off sunblock after a day in the sun

(CNN) -- The cold snap that's hitting much of the country this week may leave you with a real desire to head to the beach. If you do, you may want to watch what kind of sunblock you use.

A new study from the National Institutes of Health finds that chemicals in sunscreens and personal care products that filter out UV rays may lead to infertility issues among men.

The study followed 500 couples who are part of a larger study known as the Longitudinal Investigation of Fertility and the Environment. This large study looks at the role between environmental chemicals and fertility. To get at this result, the authors took urine samples from the couples and had them keep a journal until they had conceived or had tried for 12 months.

The couples who took the longest to conceive had something in common. BP-2 or 4OH-BP, two UV filter chemicals found commonly in sunblocks and sunscreens, were found in high concentrations in the male partner's urine. The chemicals are also used in moisturizers and shampoos.

Germaine Buck Louis, the lead author of the study, said there hasn't been much work done in this area.

"Right now, it's thought (these chemicals) are safe for use -- in preventing ionizing radiation and sunburn, but what about better health?" she asked.

She added that it is unclear exactly what role these chemicals may play in decreasing male fertility.

So what can you do if you want to keep your skin cancer-free, but are concerned about fertility issues?

The scientists say not much. There is no law that requires manufacturers to disclose the chemicals are in their products. They aren't on the ingredient list on the packaging. Buck said she believes that as more is learned about these chemicals and the unintended consequences they may have on your health, that may change.

Scientists say one thing to do is make sure you wash off the product after your day out in the sun.