In-Flight UV-A Exposure of Commercial Airline Pilots.

INTRODUCTION: Understanding UV exposure is essential for the assessment of its contribution to the occupational risk of pilots developing ocular and skin pathologies. The objective of this observational study was to measure the UV exposure of pilots flying between the United Kingdom and a range of destinations at three different seasons.METHODS: The in-flight UV exposure of pilots was measured on 322 Monarch Airlines short-haul flights on the Airbus A321-231 and Airbus A320-214 to 31 destinations, mostly in Europe, from 4 UK airports in September 2016-August 2017. The erythema effective and UV-A doses were compared with the ICNIRP guidance and typical recreational weekend exposure of UK office workers.RESULTS: The erythema effective radiant doses did not exceed 0.1 SED. For most of the flights, the UV-A exposure was also low. On 27 single sector flights, UV-A exposure could have exceeded the ICNIRP guidance if eye protection was not used.DISCUSSION: The UV exposure in a cockpit is mostly governed by the presence of direct sunlight and the duration of a flight. The average monthly exposures were low and significantly below weekend recreational exposures of UK office workers over a similar period. To assess the contribution of occupational UV exposure to the risk of developing sun-related ocular and cutaneous pathologies, it is important to consider the accumulative flight time, destinations, and UV attenuation of aircraft windshields. Additionally, leisure and recreational outdoor time needs to be considered before meaningful overall risk analysis can be undertaken.Baczynska KA, Brown S, Chorley AC, O'Hagan JB, Khazova M, Lyachev A, Wittlich M. In-flight UV-A exposure of commercial airline pilots. Aerosp Med Hum Perform. 2020; 91(6):501-510.

Sunglass Filter Transmission and Its Operational Effect in Solar Protection for Civilian Pilots.

INTRODUCTION: The ocular effects of excess solar radiation exposure are well documented. Recent evidence suggests that ocular ultraviolet radiation (UVR) exposure to professional pilots may fall outside international guideline limits unless eye protection is used. Nonprescription sunglasses should be manufactured to meet either international or national standards. The mean increase in UVR and blue light hazards at altitude has been quantified and the aim of this research was to assess the effectiveness of typical pilot sunglasses in reducing UVR and blue light hazard exposure in flight. METHOD: A series of sunglass filter transmittance measurements were taken from personal sunglasses (N = 20) used by pilots together with a series of new sunglasses (N = 18). RESULTS: All nonprescription sunglasses measured conformed to international standards for UVR transmittance and offered sufficient UVR protection for pilots. There was no difference between right and left lenses or between new and used sunglasses. All sunglasses offered sufficient attenuation to counter the mean increase in blue light exposure that pilots experience at altitude, although used sunglasses with scratched lenses were marginally less effective. One pair of prescription sunglasses offered insufficient UVR attenuation for some flights, but would have met requirements of international and national standards for UV-A transmittance. This was likely due to insufficient UVR blocking properties of the lens material. CONCLUSIONS: Lenses manufactured to minimally comply with standards for UVR transmittance could result in excess UVR exposure to a pilot based on in-flight irradiance data; an additional requirement of less than 10% transmittance at 380 nm is recommended.

Occupational Ocular UV Exposure in Civilian Aircrew.

INTRODUCTION: Ultraviolet radiation (UVR) increases with altitude; however, there are a number of other factors which may influence ocular exposure during flight. The aim of this study was to assess ocular UVR exposure of pilots in airline and off-shore helicopter operations on different aircraft types and to compare with exposure in a typical office environment. METHOD: In-flight data were captured on equipment including a CCD array spectroradiometer on five return sector European airline flights and one transatlantic flight from London Gatwick in addition to four helicopter flights from Aberdeen Dyce airport. Further data were collected in an office environment from three workstations during summer and winter months. RESULTS: A wide variation in ocular UVA dose was found during flights. The main factor influencing exposure was the UVR transmission of the windshield, which fell into two distinct profile types. In an aircraft with good UVA blocking properties, ocular exposure was found to be equivalent to office exposure and did not exceed international guideline limits regardless of external conditions or flight time. Most aircraft assessed had poor UVA blocking windshields which resulted in an ocular exposure to the unprotected eye in excess of international guideline limits (up to between 4.5 to 6.5 times greater during one flight). No significant UVB dose was found. DISCUSSION: Pilots should be warned of the potential high UVA exposure during flight and advised on the use of sunglasses. A windshield labeling system would allow the pilot to tailor their eye protection practices to that particular aircraft.

Solar Eye Protection Practices of Civilian Aircrew.

INTRODUCTION: There is good evidence that long term exposure to ultraviolet (UV) radiation increases the risk of cataracts. The 'blue light hazard' is considered a risk factor for retinal changes similar to those seen in macular degeneration. Previous studies ascertaining the prevalence of radiation related ocular disease in pilot cohorts have not considered use of solar eye protection. The aim of this study was to explore pilot use of sunglasses and other solar eye protection habits and to gain insight into the difficulties encountered managing sunlight on the flight deck. Additionally, the prevalence of radiation related ocular pathology in the study group was calculated. METHODS: A web based questionnaire was developed and administered to a large population of current UK professional pilots. RESULTS: There were 2917 respondents who completed the questionnaire, demonstrating a wide range of sunglass use during flight. A number of barriers to sunglass use were identified, the most prevalent being the requirement for corrective lenses to be used. Pilots most commonly increase sunglass use due to ocular health concerns. A high level of dissatisfaction with standard aircraft sun protection systems was reported. Long haul airline pilots were the highest users of nonstandard sunlight blocking strategies. No correlation between reported pathology and flying experience was found. DISCUSSION: The use of sunglasses during flight is complex; however, a number of practical recommendations can be made to increase the success for those pilots who wish to use sunglasses more. Aircraft manufacturers should consider how greater control of cockpit sunlight levels can be achieved.

A Modified Protocol for Color Vision Screening Using Ishihara.

INTRODUCTION: The Ishihara plates are commonly used as an initial occupational screening test for color vision. While effective at detecting red-green deficiencies, the color deficient subject can learn the test using different techniques. Some medical standards such as the European Aviation Safety Agency (EASA) require plate randomization and apply a stricter pass/fail requirement than suggested by Ishihara. This has been reported to increase the false positive rate up to ∼50%. METHOD: Two modifications to the Ishihara protocol are investigated. These involved allowing subjects a second attempt where one or two reading errors were made and the presentation of rotated Ishihara plates. RESULTS: A reduction of false positive rate to 5.9% was found. Correct identification of certain rotated Ishihara plates was not affected. DISCUSSION: By using a modified Ishihara protocol, fewer color normal subjects would require unnecessary advanced color vision examination. Further, additional safeguards would be in place to ensure that no subject with a color vision deficiency could pass the Ishihara test.

Civilian pilot exposure to ultraviolet and blue light and pilot use of sunglasses.

Population and animal studies indicate that long-term exposure to short-wavelength visible light and ultraviolet (UV) radiation causes increased risk of certain ocular pathologies such as cataracts and maculopathy. The potential risk to flight crew is unknown. The UK Civil Aviation Authority (CAA) has issued guidance to pilots regarding sunglass selection; however, it is not known if this guidance is appropriate given pilots' unique occupational environment. A search and appraisal of the relevant literature was conducted which showed that within the airline pilot population, there is limited evidence of a higher prevalence of cataracts. There are no data of other known UV-related ocular pathology. There is some evidence of higher prevalence of skin melanomas. Studies measuring cockpit UV radiation levels are limited and leave unanswered questions regarding airline pilot exposure. Data from optical transmission of cockpit windshields demonstrates the UV blocking properties at sea level. No studies have addressed the occupational use of sunglasses in airline pilots. Although it is likely that an aircraft windshield effectively blocks UV-B, the intensity of UV-A and short wavelength blue light present within the cockpit at altitude is unknown. Pilots may be exposed to solar radiation for periods of many hours during flight where UV radiation is known to be significantly greater. Aircraft windshields should have a standard for optical transmission, particularly of short-wavelength radiation. Clear, untinted prescription glasses will offer some degree of UV protection; however, sunglasses will offer superior protection. Any sunglasses used should conform to a national standard.