Answer to Question #11747 Submitted to "Ask the Experts"
Category: Pregnancy and Radiation — Flying
The following question was answered by an expert in the appropriate field:
I would like to inquire if traveling during the first trimester would expose my baby to high ultraviolet (UV) radiation levels at high elevations. I will fly around 11,560 kilometers (km) or 14 hours (approximate flight duration from Europe to Asia).
While UV radiation levels are higher with increasing elevation, your baby will not be exposed at all. Ultraviolet radiation exposure does increase with elevation—about 9–20% per km of elevation—but the depth of penetration of UV photons does not change.
UV light is unlikely to penetrate any deeper than the thickness of skin (1–4 millimeters [mm]). Penetration into the skin is at the higher end for white skin and decreases for darker skin.
During the first trimester, the baby is "shielded" by approximately 80 mm of tissue. UV light cannot penetrate that far.
Certified Medical Health Physicist
Anderson RR, Parrish JA. The optics of human skin. J Inv Derm 77:13–19; 1981.