How Much Is Too Much? Japanese Government Takes Grave Risks with Radiation Exposure


Japan’s nuclear crisis isn’t going away – and long-term health impacts from the radiation are now a grave concern as the situation continues to escalate. Dozens of repair workers at the reeling Fukushima-Daiichi nuclear power plant have already been exposed to radiation levels well beyond the country’s legal yearly dose limit. So far, the highest specific exposures reported are from two workers who received – on one day alone – radiation doses of more than three times the internationally recognized annual occupational exposure limit. Reports say the workers had severe rashes on the parts of their bodies exposed to radioactive water.

Those troubling revelations prompted an even more troubling response from the Japanese government.

In a move that is certain to stunt workers’ lives and potentially plague future generations with increased cancer rates, Japan’s Ministry of Health, Labor and Welfare has lifted the internationally recognized 50-millisievert (mSv) yearly cap on occupational exposure. That specific 50-mSv limit is recognized as the lowest dose that can trigger cancer in adults. It is most definitely not an arbitrary number to be manipulated by short-sighted governments – not even during times of crisis.

Japan’s decision to abolish the cap is just the latest bombshell in a series of potentially devastating policy changes made in recent weeks, coming on the heels of government officials upping the yearly legal limit of 100 mSv in “emergency situations” to 250 mSv for workers at the Fukushima plant. To put that in perspective, 250 mSv is five times the dose at which cancer can occur in adults.

So with the stroke of a pen, we see lives endangered and industry liability limited. You have to wonder if there was a single scientist or health expert in the room when these decisions were made.

To provide some context as to just how dangerous these increases really are, here’s a list of doses and corresponding health effects.

Radiation Exposure Dosage Chart:

10,000 mSv (1,000,000 mrem) as a short-term and whole-body dose would cause immediate illness and subsequent death within a few weeks.

1,000 to 10,000 mSv (100,000 to 1,000,000 mrem) in a short-term dose would cause severe radiation sickness with increasing likelihood of fatality.

1,000 mSv (100,000 mrem) in a short-term dose will cause immediate radiation sickness in a person of average physical attributes, but would be unlikely to cause death.

Short-term doses greater than 1,000 mSv (100,000 mrem) over a long period create a definite risk to develop cancer in the future.

At doses above 100 mSv (10,000 mrem), the probability of cancer (rather than the severity of illness) increases with dose.

50 mSv (5,000 mrem) is thought to be the lowest dose at which cancer may occur in adults. It is also the highest dose allowed by regulation in any one year of occupational exposure.

20 mSv/yr (2,000 mrem) averaged over five years is the limit for radiological personnel such as employees in the nuclear industry, uranium or mineral sands miners and hospital workers (who are all closely monitored).

10-12 mSv (1,000-1,200 mrem) in one dose is the equivalent of a full body CT scan.

3 mSv/yr (300 mrem) is the typical background radiation from natural sources in North America, including an average of almost 2 mSv/yr from radon in air.

2 mSv/yr (200 mrem) is the typical background radiation from natural sources, including an average of 0.7 mSv/yr from radon in air. This is close to the minimum dose received by all humans anywhere on Earth.

0.3-0.6 mSv/yr (30-60 mrem) is a typical range of dose rates from artificial sources of radiation, mostly medical. It includes bone density scans, dental X-rays, chest X-rays, and bone X-rays.

0.01-.03 mSv (1-3 mrem) is typical radiation from a single coast-to-coast airplane flight. However, high-mileage frequent flying (100,000 to 450,000 miles per year) can range from 1 to 6 mSv (100-600 mrem) per year.

This chart lists ionizing radiation only. Of all the types of non-ionizing radiation, only ultraviolet rays are cancer-causing agents.

*Sources: World Nuclear Association and

Instead of taking corrective measures to protect its people, Japan has simply increased internationally recognized exposure limits. It seems that the priority – as we’ve seen in so many other industrial disasters in so many other countries – is to protect industry and limit its liability rather than to ensure the long-term health and well being of the masses. Go figure. Another recent example of this phenomenon can be seen in the U.S. government’s ill-advised decision to raise the allowable levels of oil residue in Gulf seafood after the BP spill. Again, the objective was to protect the multibillion-dollar seafood industry and to limit BP’s liability. We can expect to see the Japanese government follow suit regarding its radiation-contaminated seafood.

This latest announcement out of Japan brought a flurry of criticism from radiation and health experts around the world. The Mainichi Daily News quotes Masanobu Nishino, secretary-general of the Kansai Occupational Safety & Health Center: “Considering the fact that workers are exposed to only around an average 1 millisievert of radiation a year through regular inspections at nuclear power plants, even the limit of 50 millisieverts is too much and this raises concerns over workers’ health. It should be the role of the health ministry to instruct workers to be exposed to no more than 50 millisieverts.”

Mr. Nishino is right. Fifty milliesieverts is too much, and to that point, the International Commission on Radiological Protection (ICRP) has proposed that levels be reduced to 20 mSv per year for occupational exposure. As an attorney who has tried multiple radiation-poisoning cases and somebody who has witnessed first-hand the ravages of radiation on the human body, I’ve been arguing until I’m purple in the face that occupational exposure limits are set too high – and there’s plenty of science to back up that claim. Yet Japan is moving in the wrong direction. Even when struggling to control an escalating crisis, governments have a responsibility to protect their people. And Japan simply has not done that.

In addition to the occupational increases, Japanese officials previously raised the limit of “safe” radiation exposure for school children from 1 millisievert per year to 20 millisieverts – a mind-boggling move that was met with outrage from many radiation experts. By increasing the limit, children living near the damaged Fukushima plant were allowed on playgrounds containing high levels of radioactivity.

A June 2 article in the Los Angeles Times depicts a contentious, emotionally charged debate over the limit hike:

The government’s initial raising of the exposure limit for schoolchildren prompted one key nuclear adviser to quit in protest. At times fighting back tears, Toshio Kosako, a professor at the University of Tokyo and an expert on radiation exposure, told reporters in late April that he was against what he considered inappropriate radiation limits.

“I cannot allow this as a scholar,” said Kosako, who was appointed by Prime Minister Naoto Kan. “I feel the government response has been merely to bide time.”

In recent weeks, doctors and environmental groups had also weighed in with criticism. Physicians for Social Responsibility, a U.S. nonprofit, blasted as “unconscionable” Japan’s radiation standards at schools in Fukushima prefecture.

David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists, another U.S. nonprofit, said the current danger was real.

“If I were a parent of a child in school there, I wouldn’t be happy either,” he said. “The new limits do not mean that a child will develop leukemia in the next year, but it does pose an elevated risk.”

As one emotional parent said at a government-convened meeting in Tokyo last month: “In the playground, in the sandbox, children put dirt into their mouths! They breathe in the dust! You should do the same! Lick the dirt! You wouldn’t do this to your own kids!”

Well, I’m happy to report that due to overwhelming public and political pressure, the Japanese government has reversed the exposure increase for children, returning the legal limit to 1 millisievert. According to the Los Angeles Times article, Japanese officials said they would also cover the cost of removing the surface soil from schoolyards where the radiation limit is exceeded. That’s the one piece of good news in this otherwise entirely disturbing situation.

So what are the possible consequences of Japan’s exposure-limit increases? We need look no further than the 1986 Chernobyl disaster, a crisis that draws many parallels to Fukushima. The radiation released from Chernobyl continues to have devastating health effects on people in the region, more than two decades later. The World Health Organization (WHO) states that the Chernobyl accident will cause 50,000 new cases of thyroid cancer among young people living in the most heavily impacted areas around the plant. And I should note that many experts believe the number 50,000 is far too low. The rate of thyroid cancer in teenagers, 15 to 18 years old, according to the WHO, is now three times higher than it was before the 1986 disaster took place. There has been a 10-fold increase in the rate of thyroid cancer in children who lived near the Chernobyl plant.

With so much human suffering at stake, the Japanese government should think long and hard about reversing the occupational-exposure increases it has instituted. The workers who are risking their lives to bring the Fukushima plant under control deserve better.

Read the full Mainichi Daily News article on Japan’s increases to occupational exposure limits:

Read the LA Times report on reversing the limit hike for school children:

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Stuart H. Smith is an attorney based in New Orleans fighting major oil companies and other polluters.
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