The U.S. Food and Drug Administration recommends using sunscreen with...

The U.S. Food and Drug Administration recommends using sunscreen with a sun protection factor (SPF) of 15 or higher. Credit: iStock/Wavebreak Media LTD

Readers have asked questions about the long-term effects of sunscreen on the body and about whether to wash clothes after you buy them. Here are medical experts' answers.

QUESTION: I use sunscreen so that I don’t get skin cancer. Are there any health risks associated with sunscreen?

ANSWER: It’s not clear. A study published May 6 in the Journal of the American Medical Association found that four common active ingredients in sunscreen are absorbed in the bloodstream. 

Still unknown is whether the absorption of those chemicals presents a health risk. The U.S. Food and Drug Administration, which conducted the study, is calling for more research.

What should you do in the meantime? Dr. Ashfaq Marghoob, director of clinical dermatology at the Memorial Sloan Kettering Skin Cancer Center in Hauppauge, offers this advice: “Limit the amount of outdoor direct sun exposure, seek shaded areas and use protective clothing.”

If you do spend a lot of time in the sun, experts advise you to use sunscreen, because it is a proven way to reduce the risk of skin cancer. Nearly 90 percent of skin cancer is linked to exposure to UV radiation from the sun, according to the Skin Cancer Foundation.

After the study was released, the American Academy of Dermatology released a statement that urged people to continue applying sunscreen that has an SPF (sun protection factor) of 30 or higher.

“These sunscreen ingredients have been used for several decades without any reported internal side effects in humans,” the academy’s president, George J. Hruza, said in the statement.

The FDA also encouraged continued use of sunscreens. The agency recommends sunscreen with an SPF of 15 or higher.

If you’re concerned about the absorption of sunscreen in the bloodstream, Marghoob suggests looking for sunscreen or sunblock with zinc oxide, titanium dioxide or both.

“They are inert products that go on the skin and the sun will just get reflected like a mirror off of them,” he said. “They do not get absorbed into the blood.”

The sunscreens in the FDA study absorb ultraviolet radiation, Marghoob said. They are far more popular than products with zinc oxide or titanium dioxide because the latter “tend to be thicker, and a little harder to get on and leave you a bit of a ghostly sheen, as opposed to a sunscreen, which completely disappears on your skin.”

The amount of sunscreen that is absorbed into the blood depends on the amount of sunscreen applied, how often it is applied and how much of the body you put it on, Marghoob said.

QUESTION: I like the look of clothes right off the rack, so I wear new clothes without washing them first. Now I wonder whether that’s a good idea. Can I catch something from unwashed clothes?

ANSWER: Dr. Aaron Glatt, chairman of the Department of Medicine at South Nassau Communities Hospital in Oceanside and an infectious-diseases expert, said probably not.

“Looking at it purely from an infection point of view, the risk would be 100 percent dependent on whether other people, or a significant number of other people, tried it on, and you’re the ninth person to wear that,” Glatt said. “You don’t know the hygiene of the people who tried it on beforehand. You may or may not be exposing yourself to some sort of a potential for an exposure. The risk is still very low, but I can’t say that it’s zero.”

Two unpleasant possibilities, Glatt said: Contracting pubic lice from trying on pants or head lice from trying on a hat.

“If it’s something other people could have tried on, it might not be the worst thing in the world to go and wash that before you wear it,” he said.

There’s no such risk in wearing a newly bought item that was sold in a sealed plastic bag, Glatt said.

“The real risk in those situations — and it’s a relatively small risk — is if you have various dyes or materials, chemicals, that are on these, that theoretically might give you an irritation, a contact or an allergic type of dermatitis, that can annoy somebody,” he said. “It could possibly be an irritant to their skin.”

If you are concerned about allergic reactions, you may want to wash any new clothing, whether pre-wrapped or not, Glatt said. Washing clothes releases some chemicals that otherwise could come in contact with the skin, he said.

Answers to health-related questions will appear periodically. If you have questions you’d like answered, email them to Newsday reporter David Olson at