Sept. 17---The recent attacks on the World Trade Center
undoubtedly resulted in releases of dioxin and asbestos into the
air. Still experts say there is no cause for alarm.
In fact, the biggest concern is the dust
firefighters, medics and others are breathing as they carry out
relief efforts at the blast site.
"I wouldn’t worry so much about exposure to
dioxin and asbestos," says Dr. Jim Hairston, an Alabama
Cooperative Extension System water quality scientist. "What I
worry about is the dust that’s being stirred up and the fact that
people involved in relief efforts are breathing it."
The dust is made up of pulverized concrete and other
substances caused by the explosion of the jet fuel and the
subsequent burning that occurred.
"You have this very fine powder, almost like
volcanic ash, that was released into the air as a result of the
explosions," Hairston says. "The problem is when you
breathe this and get it into your lungs."
"It’s not as bad as asbestos, but it does
have a damaging effect on the lungs. If you breathe too much of it
at one time, it can even kill you."
Another potentially serious problem is the massive
volume of dust that will be turned into mud during rainfall.
"When you get a major rainfall, this powder
will turn to mud and wash into the voids were there still may be
survivors," Hairston says. "Over time, this power, like
any fine powder, will harden into a firm material."
This may also pose a long-term problem for New York
City’s infrastructure, Hairston says, once the material washes
into sewers and hardens.
"The rainfall transforms the dust into a liquid
slush flow – a real problem during and immediately following heavy
rain," Hairston says. "Once it washes into underground
sewers, it won’t be easy to flush out."
As a result, he says, city workers may have to go in
and dig up these sewers – a very expensive undertaking in the long
One major concern after the attack involved the
levels of dioxin and asbestos released after the explosions.
An extremely toxic material, dioxin is released by
low temperature burning of substances such as jet fuel that ignited
the World Trade Center towers. Other materials within the Twin
Towers may also have released dioxin during burning.
Asbestos, associated with lung cancer, is a highly
heat-resistant fibrous material used routinely in building
construction, especially insulation, until several years ago.
"There will be concentrations of dioxin and
asbestos caused by the explosion of the jet fuel and the subsequent
burning," says Hairston. "But they are not at high enough
levels to cause any harm."
In fact, the Environmental Protection Agency, which
has monitored air-pollution levels round the clock since the blast,
says these levels have not reached what is considered upper limits
for dangerous substances.
People facing the greatest risk from exposure to
these substances will be those involved in cleanup efforts that will
follow rescue efforts within the next few weeks, Hairston says.
While asbestos has not reached dangerous levels, EPA
officials have detected elevated asbestos levels in the rubble, even
though the Twin Towers were among the first buildings in the United
States not constructed with asbestos. And even though the building’s
steel structure was treated with a spray-on ceramic fireproofing
material, this does not mean other building materials within the
center did not contain asbestos, Hairston says.
"Even when a substance such as asbestos is
banned, it may take years before construction materials containing
asbestos are removed from the market," Hairston says. Under the
circumstances, he says, it’s possible some of the building
materials used to construct the Twin Towers contained
Hairston also recommends EPA officials check for
lead levels at the blast site. That’s because as a 30-year-old
structure, the World Trade Center may have also contained paint and
plumbing material with lead.
The Twin Towers, two of the seven buildings
comprising the World Trade Center, were completed in 1973.
(Source: Dr. Jim
Hairston, Extension Water
Quality Scientist, 334-844-3970.)