BUFFALO, N.Y. -- As the 66th anniversaries of the Hiroshima and
Nagasaki bombings approach on August 6 and 9, a University at
Buffalo biostatistics and public-health expert says that studies of
health effects from those events provide some clues to the
potential, long-term health impacts of this year's Fukushima
nuclear disaster in Japan.
At the same time, he says, the Fukushima power plant disaster
underscores how little is yet known about the health effects of
Since 1989, Randolph Carter, PhD, professor and associate chair
of the department of biostatistics in the UB School of Public
Health and Health Professions, has worked with the Radiation
Effects Research Foundation (RERF) in Japan, which conducts
population-based studies on the survivors of the Hiroshima and
Nagasaki atomic bomb detonations. Carter used RERF data to develop
the Cardiovascular Metabolic Risk Index to study correlations
between radiation dose and the incidence of cardiometabolic risk
factors among survivors.
He says that the first and most noticeable health effects
expected to emerge in people exposed to the highest radiation doses
during and after the Japanese nuclear disaster are thyroid
disorders, such as hypothyroidism, some thyroid cancer cases and
"I'd expect that the power plant workers who received high doses
would be at increased risk of the same diseases that were seen
among atomic bomb survivors," says Carter, "such as thyroid
diseases first and leukemia, to be followed in subsequent years by
small increases in risk factors for cardiovascular and metabolic
diseases, such as hypertension. "
But because the amount of exposure that the general population
received was so much lower than what the power plant workers
experienced, he says it isn't certain that they will present the
same kinds of diseases seen in the bombing survivors.
"Since the doses were so much lower, it may be that we will see
nothing in terms of elevated disease levels in the population
living near the Fukushima Daiichi plant," he says.
Part of the problem in trying to forecast what kinds of health
effects will occur in the general population as a result of their
radiation exposure is that so little is known about how low-dose
radiation affects human health.
In fact, Carter says that the Fukushima nuclear disaster
provides researchers with an important new opportunity to gather
data on how low-dose radiation, in particular, affects the health
of those exposed to it.
While radiation specialists note that cumulative doses of 500
millisieverts, a unit of measurement of radiation, raise cancer
risks, Carter says that based on his own research and research by
colleagues in the field, there is evidence that doses of radiation
lower than 500 millisieverts raise cancer risk as well.
"These data indicate that doses below 500 millisieverts and
perhaps as low as 160 millisieverts carry an increased risk of
leukemia," says Carter.
"Our research at UB shows that both cardio-metabolic risk and
the proportion of lymphocytic blood cells with genetic damage
increases the risk of cancer in atomic bomb survivors as radiation
doses exceed 240 millisieverts."
He adds that debate over the effects of low dose radiation
ranges from an argument that low-doses may pose even more
significant threats to human health than do higher doses, per unit
of dose, to arguments that low-dose radiation can be beneficial
because of the possibility that when radiation kills cells in the
body, it kills off cells that are precancerous.
"Nobody really knows what to expect because there haven't been
studies of large groups of people exposed to low doses of
radiation," he says. "Most of the information we have on radiation
health effects comes from the atomic bomb studies and those didn't
involve low doses. That's why I think it's important that studies
be initiated now, in the aftermath of this disaster, to assess the
dose that individuals received. These data will be very useful in
the future in assessing the impacts of low doses of radiation."
The University at Buffalo is a premier research-intensive public
university, a flagship institution in the State University of New
York system that is its largest and most comprehensive campus. UB's
more than 28,000 students pursue their academic interests through
more than 300 undergraduate, graduate and professional degree
programs. Founded in 1846, the University at Buffalo is a member of
the Association of American Universities.