Health Implications in the Aftermath of Japan's Crisis
Mental Health, Radiation Risks, and the Importance of Continued Surveillance

What do you view as Japan’s most urgent health concerns in wake of the recent tragedy?

At this stage, it is quite difficult to predict the full impact of the nuclear crisis, as the extent of radiation exposure to date and in the upcoming weeks or months is not very clear. It seems inevitable that at least a small rise in cancer incidence will occur, particularly among people closest to the Fukushima plant. However, this excess risk might turn out to be quite small.

Pending developments on the nuclear front, I would say that mental health will be by far the most pressing concern both now and in the future. Altogether, mental health disorders already affect about one-fourth of people worldwide at some point in their lifetime, and account for a greater burden of disease than heart disease or cancer. The prevalence of various mental health disorders, including depression and anxiety, is known to be far higher in crisis-affected populations across various areas of the world.

In Japan, tens of thousands of people have lost a loved one. Hundreds of thousands have lost their homes and livelihoods, compounded by the stress of temporary living conditions. Many more have been exposed to various traumas—the earthquake itself and the countless aftershocks, including the massive one of April 7; the nuclear scare; and witnessing extreme suffering and devastation. Addressing mental health disorders in this very large population is going to be a major challenge for the Japanese health system, both in the short and the long-term.

Keeping stress in mind, another pressing health concern will probably be cardiovascular disease. I am aware of only one paper (from Armenia in the 1980s) suggesting that earthquake survivors are at higher risk of developing heart conditions, but stress is a known risk factor. I would guess that many elderly persons will be at some level of increased risk due to brief discontinuations in care and difficult living conditions. Much of this excess risk will probably occur over the days and weeks immediately following the disaster, and I would expect that the excellent health infrastructure of Japan will be able to contain this risk to a minimum within the next few weeks.

Infectious diseases often spread rapidly after crises. Should this also be a concern for Japan right now?

Infectious diseases are a threat in any post-disaster situation. However, given the high vaccination coverage before the earthquake, the excellent nutritional status of the Japanese population, and the availability of basic care even in evacuation centers, I would not expect major outbreaks, provided that newborns in the evacuation centers continue to receive their routine vaccines, food rations are adequate, and health services are available.

I think that the main infectious risk will be pneumonia, particularly among the elderly, due to exposure to the elements and overcrowding. Pneumonia was actually the first cause of hospitalization during the first two weeks following the 1995 earthquake in Kobe.

Despite Japan’s exceptional health infrastructure, the scale of the disaster has proved challenging and resulted in an enormous loss of life, with many people still unaccounted for. Much of your work focuses on the quantification of human casualties in crisis-afflicted regions. What difficulties are present in determining such figures in Japan at this time?

The death toll of this disaster remains unclear, largely because many public records have been lost and thousands of people are still missing. I don’t think quantifying the exact death toll is a priority now. The major challenge here will be to quantify the number of deaths in households of which no single member survived to report a family member as missing. However, I would expect that a good estimate would be easy to arrive at by analyzing missing persons’ lists and allowing extended family members to contribute to these lists. The next countrywide census will probably give the most accurate death toll estimate.

In northeast Japan, an estimated 350,000 people currently reside in evacuation centers, including 100,000 children and many elderly. What are the health risks and challenges of these living conditions during and following major disasters?

In physical terms, I don’t think that these evacuation centers pose major health risks, as long as vaccination programs continue, basic health care is available on site with the opportunity for quick referral to nearby hospitals in case of complications, and food rations are sufficient in quantity and quality (micronutrient content). The information I have is that these basic conditions are currently met, and one can expect that conditions will improve as better accommodations are found for the evacuees.

What measures should be taken to facilitate physical and mental health wellness in these evacuation centers?

Mental health, as I mentioned above, is a paramount concern. Ensuring a modicum of privacy and sufficient living space, as well as promoting community groups for evacuated survivors, should be priority interventions in these evacuation centers. Actively identifying persons in emotional and mental distress and initiating care for them would also be essential. Much has to do with the duration of exposure: the sooner people can be moved to better accommodations, the better for their mental health.

You mention that most of the basic conditions are being met in evacuation centers, but what about for the general Japanese population? Water issues—both shortages and radiation contamination in particular—continue to draw major attention. In your opinion, what are the health risks from water consumption right now and possibly in the future?

I don’t think that temporary shortages of potable water or unfiltered water consumption in some areas will bear major health risks. Thus far, no major outbreak of waterborne disease has been reported. Some of the obvious risk factors—malnutrition, environmental or human reservoirs of diseases such as cholera, dysentery, and typhoid, and lack of sanitation—are just not there in this scenario. Furthermore, where people are overcrowded (in the evacuation centers), clean water seems to be available. Even if a major outbreak began, I suspect that authorities would quickly be able to bring it under control.

Consumption of water contaminated with radiation is a different matter. Here, the risk is very difficult to quantify at present, as it is a function of the dose one is exposed to, which is unclear right now, given both what may happen in the next few weeks, and that people may respond to health warnings in various ways—for example, by drinking only bottled water from safe sources.

There are three main types of effect from exposure. First, in the case of a large dose, immediate radiation poisoning may occur, ranging from blood disorders (e.g. anemia or a drop in white blood cells) to gastrointestinal problems to more neurological (e.g. dizziness or loss of consciousness) or skin problems. I doubt that radiation levels for the vast majority of Japanese will reach high enough levels to cause these problems. Second, radiation exposure leads to an increased risk of birth defects and genetic mutations. Lastly, there is an increased risk of various cancers in the long-term.

Basically, risks two and three are never nil, but may range from minimal to very substantial, depending on the level of intake. I think it is still too early to venture a guess as to the magnitude of these risks.

Just as a benchmark, the UN estimates that as of 2005, about 6,000 cancer cases have resulted from the Chernobyl disaster, while scientists working for Greenpeace have put the death toll of that disaster at 200,000! While the latter may be an overestimate, this illustrates the difficulty in accurately estimating the extent of health effects from a nuclear crisis—the effects are varied, of complex attribution, and diluted across decades and large populations. Thankfully, most scientists agree that the Fukushima disaster is of considerably lesser magnitude than Chernobyl’s.

You’ve pointed out that tracking specific effects of the crisis will prove difficult in the short-term. The Japanese continue to conduct the world’s longest longitudinal study of radiation poisoning, which dates back to 1945 and still monitors the health of remaining atomic bomb survivors. Does this position the Japanese well to track both existing and prospective issues from the current nuclear crisis? In general, how can Japan best monitor the health of the crisis-affected population, both at present and in the future?

The Japanese have excellent epidemiology and biostatistics research centers and are as well equipped as anyone to issue good estimates of the public health effects of this disaster, particularly as regards radiation exposure.

Right now, reinforcing public health surveillance would be key in order to pick up abnormally high mortality in specific population groups, communities, or evacuation centers, detect any outbreaks early, and observe any signals of radiation-attributable illness. In the long-term, useful methods for monitoring health status might include reinforcing cancer and birth defect registries, and establishing prospective cohort studies among disaster survivors that quantify mortality and also the prevalence and incidence of various diseases of interest. Again, I would stress mental disorders as well as suicide as key health events to monitor. All of these studies generally require a control group—people that were less or not at all exposed to the disaster.

It can be helpful to compare a current situation to similar events. How does the Japan disaster compare to other crises that you’ve experienced through your work? Is there a comparable situation in terms of its health challenges and outcomes?

The combination of earthquake, tsunami, and nuclear disasters is unprecedented. On the other hand, this is all taking place in one of the world’s best-prepared countries. As such, the situation is very difficult to compare with recent earthquakes in Haiti or Pakistan, or armed conflicts in sub-Saharan Africa.

There are two critical differences to consider in the aforementioned cases. First, people in resource-poor settings are already very vulnerable before the disaster—their nutritional status is low, they are unvaccinated, they live in areas endemic for various infectious diseases, and they don’t have well-functioning health services. Second, relief efforts in such settings are often hampered by insecurity and inaccessibility, as well as insufficient funding by donors.

It is important to remember that Japan is one of the richest, healthiest countries on earth, with a vast capacity for disaster response. In these respects, the situation in Japan compares to no other I’ve experienced—again, the only real common feature may be the high risk of mental disorders. Indeed, MSF teams currently responding to the disaster are focusing their efforts on mental health, which, even in rich countries, remains a neglected area of public health.

Thankfully, Japan today is much better placed to respond to this disaster.

This interview was conducted by Rebecca Kennedy and Karuna Luthra, interns at NBR.