Aerotoxic Association

The following text was translated by the Aerotoxic Association from this article in German on the Das Erste website


Air travel: Obligation to report disregarded?
Interview with Prof. Dr. Henschler, Würzburg


Programme shown on Tuesday 24th März 2009 on WDR "Das Erste"


Prof. Dr. Dietrich Henschler was born in 1924 and studied medicine. He took a doctorate in 1953 in Würzburg. In 1957 he qualified as a professor at the Pharmacological Institute in Würzburg on the subjects of the structure-response relationships and response mechanisms of the neurotoxic tricresyl phosphate (TCP). From 1969 to 1992 he was the chairman of the senate commission checking hazardous substances for the DFG (German Research Foundation). This commission established maximum allowed concentrations for chemicals in the workplace. He is a co-editor of a textbook about toxicology and numerous monographs about hazardous substances. Since the report by plusminus on 3rd February 2009 he has familiarised himself with the subject of contaminated cabin air. On 18th March he also gave a detailed interview to ARD. Here some extracts:


plusminus: Is inhaling tricresyl phosphate (TCP) harmless or hazardous?

Prof. Dr. Henschler: I believe it to be hazardous. It is often argued that the processes that take place through intake by food or by absorbing through the skin can’t occur by inhalation. But this based on a false assumption. It is a fact that the TCP itself doesn’t cause an effect, but a metabolite, a by-product of enzymes in the body. And so it’s irrelevant how the TCP gets into the body. It is so fat-soluble that it can be taken in though the skin, through the mucous membranes of the respiratory tract and through the gastrointestinal tract. It really doesn’t matter.

plusminus: Why is the problem underestimated so much?

Prof. Dr. Henschler: It's embarrassing that there are even professional colleagues of mine who do not trouble themselves to contemplate it. This is a superficial way of thinking. And then there are the authorities: the people who set the standards – the workplace standards too - they delude themselves over and over again. And as I understand, also the experts who have to evaluate the problems for aviation.

plusminus: Were your findings from 1958 ever discussed with oil manufacturers, the military or governments?

Prof. Dr. Henschler: The industry was in the know straight away. There were discussions with them, even though it was quite clear what their interests were. In the end they also acknowledged the results. I had contact with the military only once: I was called to Morocco when there was the mass poisoning in 1959. There were 10,000 affected people. The French government asked me to look at a product to determine the cause.

plusminus: And how did this poisoning come about?

Prof. Dr. Henschler: It was jet engine oil. It was being used on an American military base for the fighters there. A local had acquired a drum and diluted it with cooking oil and distributed it on the streets. There were 10,000 victims who were paralysed for the rest of their lives.

plusminus: What can or should be done to help people in aviation affected by this today?

Prof. Dr. Henschler: In occupational medicine there are agreed strategies on how one goes forward to analyse such incidents and to make an evaluation - maybe for recognition as an occupational illness, or even to prevent it. Which measures should we take to prevent it? Nowadays it’s one of the most important procedures that one analyses precisely. That means developing a chemical analysis which gives precise information about which constituents are present and in which respective proportions. This is a general strategy in occupational medicine. Why should this not also be applied in workplaces in aircraft? Most likely one of the best solutions is filtering the air. Why this has not happened up to now is inexplicable to me. The filtering of contaminated air is a very everyday process in today's working environment.

plusminus: When you read the numerous professional publications on this subject today, what does it say to you?

Prof. Dr. Henschler: It says to me that what has already been found long ago has not been realised and implemented in a sensible manner.

plusminus: Are you surprised that TCP can end up in the cabin air of aircraft?

Prof. Dr. Henschler: Before your programme I wasn’t aware of how frequently this happens. Of course it surprises me, indeed in an unpleasant way. With our knowledge of toxic effects and after reports about tens of thousands, maybe even hundreds of thousands of victims in medical records, I would have expected that one would have looked for better alternatives. In my eyes there are some, but one just has to take the trouble with it.


This interview was conducted by WDR author and aviation journalist Tim van Beveren

Original German version