A new research by Food and Drug Administration (FDA), the US food and drug warrant body, followed up on a pilot study published last year. And it confirms: Six active ingredients found in sunscreen products can be detected in users' blood even after just one application.
However, several experts questioned about the study urge to continue using sunscreen. Sun damage is already established, while we still don't have a measure of the health impact of chemicals in UV protection products.
The pilot study still left doubts
Last year, the FDA released the results of a small pilot study. This study found that regular application of several common sunscreen formulations resulted in detectable blood concentrations of four chemicals: avobenzone, oxibenzone, octocrylene and ecamsule. At the time, the study was criticized for the small sample size, as well as for the excessive levels of product tested.
This follow-up study expanded the sample size, tested a large assortment of active ingredients, and studied blood absorption even after a single application of sunscreen.
The new research has dispelled all doubts
New research has found that 6 major chemical ingredients active in sunscreen can be present in detectable concentrations in the blood even after just one application. All six chemicals (avobenzone, oxybenzone, octocrylene, homosalate, octosalate and octinoxate) were found in concentrations above 0,5 ng / mL.
The 0,5 ng / mL threshold found in the study is not established as intrinsically insecure, but FDA researchers consider it significant, because the risk of cancer below this threshold is less than 1 in 100.000.
In an "ecumenical" and neutral way, the study does not investigate and does not hypothesize the carcinogenic effects of these substances in the blood, but will make sure that companies ask themselves the problem.
Sun creams: are chemical filters bad?
Rob Chilcott, a toxicologist at the University of Hertfordshire, says the study results were predictable, as it is known that skin is not a solid barrier and can absorb chemicals even from surface applications.
"This doesn't mean that sunscreen products are unsafe to use, but that manufacturers need to carry out proper safety tests.", he claims Chilcott, who did not work on this FDA study. "It should be emphasized that unless further investigations are made, the health risks of using sun filters and creams are not well defined. And those deriving from excessive sun exposure are potentially more harmful".
In summary, there is definitive evidence that sunscreen chemicals applied to the skin can enter the circulation. We still don't know what their health effects are. Of course, seen individually (and have been observed for some time) these 6 substances do not do well, and not only for the environment.
Which is why I continue to use protections without exaggerating. Maybe even supporting me with protective clothing without resorting to chemistry and in general without abusing sun exposure. It is the logic of the minor damage, until new developments.
Do doctors need to keep recommending chemical filters and sunscreen?
This is what is asked an editorial accompanying the study, written by Kanade Shinkai, editor in chief of the journal JAMA Dermatology.
The editorial discusses the risk-benefit considerations clinicians should use to evaluate the extent to which they recommend sunscreen to patients.
"In making an informed decision," it is read, "Physicians must determine whether the magnitude of the benefit outweighs the risk of potential harm for a specific individual. It is important to emphasize that this balance may differ. The characteristics of the sunscreen user affect (for example, for people with of darker skin and for children) and may depend on the frequency and duration of application (for example, daily vs intermittent use; starting in infancy or later in life). "