Sunscreen chemicals seep into your bloodstream after one day of use: study
May 7, 2019 | 1:55pm | Updated May 7, 2019 | 2:46pm The chemicals in popular sunscreens don’t just sit on the surface of the skin — many of them are absorbed into the bloodstream at levels that far surpass government-recommended thresholds for the compounds, according to a new study. The results of the study,…
The chemicals in popular sunscreens don’t just sit on the surface of the skin — many of them are absorbed into the bloodstream at levels that far surpass government-recommended thresholds for the compounds, according to a new study.
The results of the study, published Monday in the peer-reviewed journal JAMA, don’t mean that the active ingredients contained in sunscreen are unsafe, according to an editorial accompanying the study, written by Food and Drug Administration chairman Robert Califf and JAMA dermatology editor in chief Kanade Shinkai.
But the findings should give the industry pause, the researchers said.
“The study findings raise many important questions about sunscreen and the process by which the sunscreen industry, clinicians, specialty organizations, and regulatory agencies evaluate the benefits and risks of this topical OTC medication,” the authors wrote.
The 24 study participants were asked to apply one of four types of sunscreen spray, lotion or cream four times daily over a week to areas that wouldn’t be covered by a swimsuit, USA Today reported.
Then they measured the concentration of four different active ingredients commonly used in sunscreens — avobenzone, oxybenzone, octocrylene and ecamsule — in the participants’ blood.
If the blood absorption of any of these ingredients exceeds 0.5 nanograms per millilter (ng/mL), the FDA recommends that they undergo “nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies,” the study said.
Researchers found that the levels of all four chemicals in the participants’ bloodstreams far exceeded that even within one day — and three of the ingredients remained there for seven days, according to the study.
Oxybenzone — which, along with some other ingredients, has been found in human breast milk — reached the threshold within two hours of one application. On day seven, the concentration was above 20 ng/mL. The chemical has also been found to be toxic to coral reefs, which prompted Hawaii to ban it last year, according to USA Today.
“Because biological rationale has so often proven to be misleading, drug manufacturers must demonstrate through empirical research in humans that benefits outweigh risks for an intended use of a product in a specified population. Has sunscreen met these current requirements for safety and effectiveness?” the researchers wrote.
Still, the American Academy of Dermatologists insisted it’s important to continue using sunscreen.
“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 a statement. “Skin cancer is the most common cancer in the United States, and dermatologists see the impact it has on patients’ lives every day. Unprotected exposure to the sun’s ultraviolet rays is a major risk factor for skin cancer.”