[ RadSafe ] Fwd: Pilots UV-A radiation exposure (Hans J Wiegert)

[Pickering, John J]

I disagree with their interpretation of the findings in the article.

The article grossly under-reported the output of a typical tanning bed.  The article states a tanning bed would emit approximately 700 uW/cm2  of UVA, but according to tanning lamp manufacturers, the number is actually 7,000 to 20,000 uW/cm2  (7 to 20 mW/ cm2 ).

Also, the highest reading recorded through the windows was at 25,000' above San Jose (California), and was reported to be 250 uW/ cm2.  The limit for continuous exposure to UVA, according to the ACGIH is 1000 uW/ cm2.   Their measurements would not exceed the standard regardless of the length of exposure.

http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/tan-bronzage/index-eng.php

The above site includes some questions and answers regarding tanning bed safety.  One provided some good info.  Here's the question:

Q:  The sun produces about 2.5 mW/cm² of UVA in summer around noon. How much UVA does a typical tanning bed produce?

A:  Tanning beds typically produce between 7 to 20 mW/cm² of UVA, which is as much as 3 to 8 times the UVA the sun produces at noon in the summer.

Another oversight in the article was that tanning lamps produce some small amounts of UVB, usually between 2 and 5% of the total UV.  Although this is a small fraction, the biological potency of UVB is MUCH higher than UVA.  This adds to the invalidity of their findings, since there is no UVB transmitted through aircraft windows.



John J. Pickering
Company Radiation Safety Officer
Senior Manager, Radiation Health Protection<http://ehs.web.boeing.com/index.aspx?com=6&id=1>
Environment, Health & Safety
206.544.0356 desk | 925-337-3746 mobile
john.j.pickering at boeing.com<mailto:john.j.pickering at boeing.com>