Analysis: The formaldehyde factor|
Judy Siegel-Itzkovich , THE JERUSALEM POST
Mar. 25, 2008
The report that Israel Air Force pilots who have flown the Lockheed-Martin
F-16I advanced combat plane have to be examined for signs of a toxic chemical in
their blood to which they were supposedly exposed in the cockpit has raised many
questions among toxicologists.
The chemical, formaldehyde, is a widely used fixative agent for tissue in
medical and scientific labs and an integral component of formica, MDF, bakelite
and other substances used for the manufacture of furniture and even car
Prof. Shmuel Yannai, one of the country's leading toxicologists who works in
the Technion-Israel Institute of Technology's department of biotechnology and
food engineering, told The Jerusalem Post on Monday that it had long been
known that formaldehyde use was problematic.
"It's used to preserve tissue in histology labs, as it kills every
pathogen-bacteria, viruses and others to prevent the tissue from deteriorating
without freezing or refrigeration," said Yannai. "This is called the fixation
Formaldehyde, as anyone who has worked in a histology or school biology lab
can attest, is "very smelly. It is problematic, as it harms the respiratory
system when inhaled.
The tissues in the trachea, bronchi, bronchioles and even the tiny alveoli in
the lungs [where oxygen/carbon dioxide exchange is carried out] react to this
very volatile chemical and become fixated‚ like lab specimens.
More recently, it has been found to be a carcinogen, although it is not the
most carcinogenic chemical. Nevertheless, there is no safe level of a
carcinogen, just as there is no safe level of a mutagenic material that causes
mutations in DNA."
But formaldehyde, Yannai said, was nevertheless used on a regular basis in
labs and in manufacturing because lab workers used protective equipment.
Carpenters and factory workers making formica and other products containing
formaldehyde know they have to protect themselves, and they are forbidden to put
their products on the market either before they have been aired out or after
they have undergone polymerization (which takes longer) so the chemical no
longer is volatile and does not release any smell.
Yannai said he believed that passenger compartments in commercial planes
contained formica and other substances made with formaldehyde, and this produced
pleasant surfaces on the internal walls of the plane. However, they have been
aired out or undergone polymerization so the formaldehyde is no longer volatile.
"But there is no reason I can think of why formica is needed inside a cockpit,"
Formaldehyde is also added to certain colors and used to facilitate drying.
It then undergoes polymerization and gives a stronger and more stable color.
Sudden and intense heating, however, could cause the vapors to be released,
just as small amounts can be felt in a car sizzling in the sun. But there is a
partial vacuum in the cockpit of a combat plane which at higher pressure slowed
down the escape of vapors from the cockpit, Yannai said.
"We have not been told what happened in this specific type of plane, what
formaldehyde was doing there and why no other model of plane has had the
problem," the Technion toxicologist said. "We need much more information. A
cockpit gets hotter and absorbs more solar radiation than a car on the ground.
Maybe there is some other explanation that the Israel Air Force knows about. If
the combat plane had a problem with its fuel, it could be removed by
distillation, but this is something different, and it can't be eliminated this
way. Mucous membranes in the nose, mouth, trachea and lungs can be harmed by
exposure to formaldehyde. It could affect the mucous membranes of the eyes, but
I'm not sure if this is a major problem."
In any case, carcinogens can take decades to show up in the form of cancer.
"Almost all types of cancer take years to present themselves," Yannai said.
Original article: Jerusalem Post
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