As summer approaches, many of us will be spending more time outdoors, but the new FDA research shows that we can expect to soak-up more than just those warm, sunny rays.
According the research, the chemicals in many of the commercially available sunblocks are absorbed into the bloodstream within 24 hours after application. The report published by JAMA on May 6, 2019, details the research protocols, results and FDA recommendations.
The 24 participants in the study apply one of four different kinds of sunscreen in spray, lotion or cream form, four times per day for four days, on all areas that are generally exposed to the sun. Researchers measured the concentration of four different active ingredients in the participants’ blood:
If the absorption exceeds 0.5 ng/mL, the FDA recommends “nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies.”
The levels of all chemicals exceeded that limit on the first day of the study and three of the ingredients remained in the bloodstream for seven days. Oxybenzone (which has been found along with other sunscreen ingredients in breast milk) plasma concentrations reached the threshold within two hours after a single application and exceeded 20 ng/mL on day 7 of the study.
Although many experts and physicians are recommending that people continue to use sunblocks to protect against skin damage and reduce the risk skin cancer, it's clear that there needs to be further research. We would also recommend looking at natural forms of topical sunblocks and reducing prolonged, unprotected exposure to the sun, especially when the UV index is high.