Exposure To Ultraviolet Radiation (Uv) In Commercial Aircraft Cockpits

Few studies have assessed UV radiation exposure in cockpits of commercial airplanes. Clinically relevant UVA radiation (315- 400 nm) levels may be present in cockpits and contribute to cataract formation.

UVA measurements were taken with the Lutron UVA-365 Light Meter in cockpits and on the ground next to airplanes. UVA levels are peak values, measured directly behind cockpit windshields inflight at cruising altitude under extreme conditions, i.e. vertical light insolation, maximal solar radiation, and high solar altitude (elevation 30-40 degrees) without any protective devices.

UVA (390-400 nm) transmission levels reached 50%, depending on cockpit windshields. Some aircrafts had cockpit windshields with optimal protective capacity, while on others up to 100 % of windshields allowed high UVA transmission. Tested windshields on Airbus A380, A350 and Boeing 747, 787 offered full protection, while 10 – 70% of tested windshields on Airbus A320, A330 and A340 and 100% on Boeing 777 did not block UVA transmission completely. In almost all airplanes tested the scatter radiation was 90-95% lower than the direct UVA radiation. The average of all maximal values of unweighted UVA radiation intensity measured was 680 μW/cm. The highest unweighted UVA radiation intensity ever measured inflight was 1380 μW /cm.

UVA (390-400 nm) transmission levels reached 50%, depending on cockpit windshields. Some aircrafts had cockpit windshields with optimal protective capacity, while on others up to 100 % of windshields allowed high UVA transmission. Tested windshields on Airbus A380, A350 and Boeing 747, 787 offered full protection, while 10 – 70% of tested windshields on Airbus A320, A330 and A340 and 100% on Boeing 777 did not block UVA transmission completely. In almost all airplanes tested the scatter radiation was 90-95% lower than the direct UVA radiation. The average of all maximal values of unweighted UVA radiation intensity measured was 680 μW/cm. The highest unweighted UVA radiation intensity ever measured inflight was 1380 μW /cm.

Measurements showed relevant UVA transmission in cockpits beyond the limits of unweighted UVA radiation intensity recommended by the International Commission on non-Ionizing Radiation Protection, both for direct transmission and scatter radiation. Importantly, UVA radiation exposure on the ground next to airplanes was twice as high as the highest value ever measured on board. In summary, pilots may not be optimally protected against UVA radiation in airplanes with cockpit windshields with suboptimal filtering capacities. As yet, there is no evidence that pilots are at a higher cataract risk, however further epidemiological studies are needed to evaluate the clinical relevance of our results and the need for further protective measures.