Pilots have higher rates of skin cancer - study

["Sandy Perle" <sandyfl@earthlink.net>]

Pilots have higher rates of skin cancer - study

LONDON, Feb 17 (Reuters) - Airline pilots have up to 25 times the 
normal rate of skin cancer and scientists in Iceland suspect it could 
be due partly to disturbed sleep patterns. 

Cosmic radiation and lifestyle factors, such as more frequent 
sunbathing, could also be involved, but scientists at the University 
of Reykjavik said pilots who flew over five or more time zones had 25 
times as many cases of malignant melanoma as the general population. 

Malignant melanoma is the most serious form of skin cancer. 

``The excess of malignant melanoma among those flying over five time 
zones suggests that the importance of disturbance of the circadian 
rhythm should be taken into consideration in future studies,'' Dr 
Vilhjalmur Rafnsson told Reuters. 

Circadian rhythms regulate sleep patterns and the hormone melatonin, 
a chemical naturally released by the brain to induce sleep. 

``Melatonin is something that inhibits the growth of cancer cells in 
experimental models. It has recently been tried in the treatment of 
malignant melanoma,'' Rafnsson said in a telephone interview. 

He stressed that the role of melatonin in the high incidence of the 
disease among the long-haul pilots was just speculation and said more 
research still needs to be done. 

``It could be a combination of bad habits (such as sunbathing) and 
melatonin. The next thing to do is to study larger groups of pilots 
and whether they are sunbathing all the time,'' he said. 

Rafnsson and his colleagues looked at the skin cancer rates of 265 
pilots who worked for Icelandic airlines and compared them with rates 
expected to develop in the general population based on data from the 
national cancer registry of people of the same age. 

Their research is published in the journal Occupational and 
Environmental Medicine. 

The pilots had higher rates of malignant melanoma than any other 
cancer. Rates for pilots flying international routes were 15 times 
higher than expected and 25 times higher for pilots flying routinely 
from Iceland to the United States. 

The pilots' estimated dose of annual radiation was well within 
accepted levels for occupational exposure. 

Melanoma accounts for about 10 percent of all skin cancers but causes 
75-85 percent of skin cancer deaths. Excessive exposure to harmful 
sun rays can increase the risk of the disease. 

Previous research by Danish scientists showed that long-serving 
pilots and cabin crew also had a higher risk of leukaemia, which 
scientists believe could be due to increased exposure to cosmic 
radiation.

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Sandy Perle					Tel:(714) 545-0100 / (800) 548-5100   				    	
Director, Technical				Extension 2306 				     	
ICN Worldwide Dosimetry Division		Fax:(714) 668-3149 	                   		    
ICN Biomedicals, Inc.				E-Mail: sandyfl@earthlink.net 				                           
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Costa Mesa, CA 92626                                      

Personal Website:  http://www.geocities.com/scperle
ICN Worldwide Dosimetry Website: http://www.dosimetry.com

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