y Michelle Fay Cortez and John Lauerman
March 18 (Bloomberg) -- A nuclear meltdown or explosion at
Tokyo Electric Power Co.’s crippled plant is unlikely to pose a
health risk beyond 50 kilometers (36 miles) of the site, doctors
and scientists said.
Workers at the tsunami-damaged facility in northeastern
Japan are battling to cool reactors and spent fuel to avert
overheating and explosions that could spew radioactive material
into the environment. Their chances of success may be improving,
with the possible restoration today of electricity to one of the
reactors that would aid cooling measures, the utility said.
Five thousand miles away, residents in some U.S. cities
have bought potassium iodide pills to protect against radiation
poisoning. Even if the cooling efforts at the Fukushima Dai-Ichi
plant fail, resulting blasts wouldn’t pose a serious threat to
Tokyo, let alone countries overseas, said Donald Bucklin, former
medical director of Palo Verde Nuclear Generating Station in
Arizona, the largest nuclear power plant in the U.S.
“This is panic, but it’s not based on scientific
reason,” Bucklin said in a telephone interview. “It’s a
horrible tragedy, but it’s a local problem. It’s not a problem
for the planet. It’s no danger to Europe, the United States and
Africa.”
The containment devices in Japan, even if compromised,
offer more protection than reactors at the world’s worst nuclear
disaster at Chernobyl, Ukraine in 1986, Bucklin said. The
lessons learned from that disaster -- mainly to beware of
tainted food, water and milk -- will help the Japanese avoid
radiation and an increased cancer risk, he said.

DNA Damage

Radiation can damage DNA, the building blocks of human life,
said Bucklin, the medical review officer for U.S. HealthWorks,
the nation’s largest private provider of occupational health
care. While the body repairs most damage, some radiation-caused
mutations can make cells malignant, he said.
The 20-kilometer evacuation cordon that Japanese officials
have put around the Fukushima reactor is “sensible and
proportionate,” John Beddington, U.K’s chief science officer,
said on a conference call March 16 with the British Embassy in
Tokyo.
Any radiation spewed from the reactor in a meltdown might
rise to as high as 500 meters (1,640 feet), and is unlikely to
reach Tokyo, 220 kilometers, or 135 miles away, he said. The
Chernobyl explosion sent radioactive dust 30,000 feet high and
continued for months.

‘Won’t Happen’

“Basically, it just won’t happen,” he said, according to
a transcript of the conference call.
The embassies of China, France and Germany in Tokyo are
among several that recommended their citizens leave the city.
Rumors have circulated by text messaging of a threatening
radiation cloud spreading across Asia and beyond from Japan, the
World Health Organization in Beijing said on March 16.
Power may be restored to one of the reactors by this
afternoon, potentially enabling workers to restart pumps needed
to pour cooling water on overheating fuel rods and avert a
meltdown or further radiation leaks, Tokyo Electric said today.
If that is successful, power may be restored to reactors 3 and 4
at the weekend, the utility said.
The more that workers can cool the reactor and ensure spent
fuel rods in storage pools are covered with water, the less
likely the situation will worsen, said Richard Lester, head of
the department of nuclear science and engineering at the
Massachusetts Institute of Technology.

Steam Explosion

If heat in the reactors can’t be controlled, melting fuel
may burn down through about seven inches of steel, and fall into
a concrete safety bed. Should the fuel remain extremely hot and
come into contact with water in the bed, there’s potential for a
steam explosion that could blast solid radioactive particles
into the atmosphere, Lester said.
Prevailing winds in the area would normally push those
particles out to sea, where they will become dispersed and pose
little risk to the public, Lester said. Were the winds to shift
and strengthen, some particles might make it to Tokyo, he said.
The probability of such a worst-case situation is “very,
very low,” and recedes further each day that the reactor’s
temperature declines, Lester said.

Howling Wind

“If a much bigger explosion occurred while the wind was
howling toward Tokyo, then you may have a little raise in
radiation,” said Bucklin, the former nuclear safety officer.
“It wouldn’t be devastating. You wouldn’t have to evacuate. It
wouldn’t kill a bunch of people. It’s a far-fetched
possibility.”
The public health risk would be equal to little more than
two additional chest x-rays, said John Lee, a professor of
nuclear engineering and radiological sciences, at the University
of Michigan in Ann Arbor. A Chernobyl type of explosion is
impossible, he said.
Twenty-eight workers died at Chernobyl within three months,
poisoned by the radiation as they tried to quell the fire, said
John Boice, professor of medicine at Vanderbilt University
School of Medicine and scientific director of the International
Epidemiology Institute in Rockville, Maryland.
Another 130 developed acute radiation syndrome, developing
nausea, vomiting and bloody diarrhea in addition to losing their
hair and key blood and immune system cells.

Contaminated Milk

Radioactive iodine was released, landing on the grass that
nearby cows ate, Boice said. They produced contaminated milk,
which the unknowing population drank, resulting in an epidemic
of thyroid cancer, with more than 6,000 excess cases developing.
The health consequences from radiation depend on how much
exposure a person has, said Richard Zane, vice-chair of
emergency medicine at Brigham and Women’s Hospital in Boston.
“It’s a pretty straightforward mathematical equation,”
said Zane, who has been involved in emergency planning for a
theoretical risk from nuclear reactors in New England. The
variables include how much radiation is released, how far a
person is from it and how long they are exposed.
Children and pregnant women are the most vulnerable, he
said. The consequences range from minimal, transient symptoms to
death, he said. Radiation primarily affects cells that reproduce
quickly, such as the lining of the stomach and gastrointestinal
tract, as well as the bone marrow that produces red and white
blood cells, Zane said.

`Not Usable'

The real danger is for the land and residents surrounding
the Fukushima facilities, Bucklin said. Radioactive elements are
heavy and don’t remain airborne very long, getting washed out
with rain and wind, he said. It’s unlikely that any countries
near Japan will have dangerous radiation elevations, and any
deposits in the ocean won’t even change background levels
already found there, he said.
“You are going to have a 10-mile circle around that plant
that’s not usable,” he said. “The soil will be contaminated
and it will be dangerous to live there for 30 or 40 years. There
may be another 20 miles you wouldn’t want to grow food crops,
but it’s probably safe to live there. Once you get 40 or 50
miles from the plant, your background radiation levels won’t
change.”
Any amount of radiation above background levels is certain
to cause alarm, and even panic. Scientists say that, as news
continues to emerge, a perspective of how dangerous the
radiation threat is may help alleviate concern.
“They already have 10,000 deaths, people washed out to
sea,” Boice said. “People are without food and water. Two and
a half million don’t have electricity. There is meaningful
concern about the workers, but for the average citizen the major
concern is not health,” he said.