SUMMER SCIENCE FRIDAY FOR ATHLETES: CAUTIOUS UV PROTECTION & SUNSCREEN USE

Evening beach walk, Texas Gulf Coast. Taken by PKSenagore January 2017. All rights reserved

SUN VERSUS SUNSCREENS. The Chicago Sun Times recently reported the results of a sunscreen study published in the Journal of American Medicine Association (JAMA) that revealed several active ingredients, avobenzone, oxybenzone, octocrylene and ecamsule “enter the bloodstream at levels that far exceed the FDA’s recommended threshold without a government safety inspection.”

After 24 study participants applied sunscreen in a manner consistent with “maximal use” conditions on 4 consecutive days (4 times a day, on 75% of body surfaces), blood tests showed that absorption into the blood stream “far exceeded” 0.5ng/mL on the very  FIRST day of the study.  At this level, the FDA recommends performance of “nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies.”

There were 4 groups; each received a different sunscreen formulation containing a combination of active ingredients as might be found in commercially available products (lotion, spray, or cream). The study protocol required application (2 mg/cm2) for 4 days and the performance of blood tests.

A conclusion of the research was that there is a need for more investigation into the “clinical significance of these findings”; there was no recommendation to discontinue use of sunscreens.

My personal use of sunscreen has been restricted to inorganic barrier products included in formulations promoted for infants and persons with sensitive skin, containing only zinc oxide and/ or titanium dioxide. I am not very likely to apply as large an amount used in the study for total body coverage, nor to re-apply 4 times a day for 4 days straight.   

However, a SCIENTIFIC review paper on the topic of neurotoxicity of various sunscreens (including nano-particle inorganic filters I use) suggests that the safety and regulation of such UV protection technologies, applied alone or in combination, has not been sufficiently established given their continuously increasing worldwide use. Safety concerns extend not only to humans but to the environment and other living systems.

The issues seem to be so complex as to be mind-boggling, and the potential hazards of using versus not using UV protection on a global scale have yet to be determined.  

What are outdoor fitness enthusiasts like me to do?  It seems wise not to completely rely on the application of products to the skin, as I have previously, but use the type of old-fashioned methods promoted before such products were created or commonly available.

Although my activities would be restricted I should perhaps give greater consideration to: enjoying the outdoors at times of the day when the sun exposure potential is lessened (mornings and evenings); wearing clothing that creates a physical barrier (like hats, sunglasses, and sleeves); and opting for shade over direct sun when possible (umbrellas, awnings, porches etc.).  

Clearly this isn’t the ultimate answer for me or the rest of the world when it comes to UV protection, but with information that harm might also be found in certain artificial protective measures I think I should budget my exposure to both the sun and sunscreens and be cautious in  acceptance of technology.

Hopefully future new UV protection could be developed with the concerns of knowledgeable scientists and the public identified and addressed up-front, rather than retro-actively investigated.

RUN & MOVE HAPPY!

https://jamanetwork.com/journals/jama/article-abstract/2733085
 
https://chicago.suntimes.com/news/2019/5/7/18621726/chemicals-in-sunscreen-seep-into-your-bloodstream-after-just-1-day-fda-says
 
http://www.marinesafe.org/blog/2016/03/18/sunscreen-pollution/
 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5615097/