The meltdown crisis that has gripped Japan’s Fukushima Daiichi nuclear power plant has reached a heightened level, with radioactive water spewing into the Pacific Ocean from the plant’s reactor two, raising new concerns about the health effects of radiation.  The radioactive leak is just one in a series of cascading disasters (demonstrating the monumental incompetence of nuclear safety) that has plagued Japan after it was struck by a massive 9.0 earthquake and tsunami on March 11.  The release of the toxic water into the ocean has the potential for serious damage to human health, as the water contains radioactive iodine and cesium, both of which can cause cancer and pose a particularly acute risk to children.

Radiation injures human beings because it is laden with highly charged atomic particles, which are tiny enough that they can penetrate through the human body, stripping away electrons from human tissue and breaking chemical bonds.  According to the EPA, “any living tissue in the human body can be damaged by ionizing radiation in a unique manner. The body attempts to repair the damage, but sometimes the damage is of a nature that cannot be repaired or it is too severe or widespread to be repaired.”  Even where the body does repair the damage, other complications from exposure can arise, most notably cancer–a disease in which cell reproduction spirals out of control.  The EPA has provided guidelines on the health effects of radiation, which are shown below in millisieverts.

Radiation levels at reactor 2 of the Fukushima Daiichi power plant have been estimated at 1,000 millisieverts per hour, which obviously presents a very serious health risk for those living in the fallout zone (wherever that may be, depending on the winds).  Indeed, this risk of inhalation or ingestion through the local food and water supply is the most serious concern for radiation exposure.

There are a number of radioactive particles being emitting from the Fukushima Daiichi plant that pose a risk to human health, notably iodine-131 and cesium-137 (plutonium has also been released from reactor 3, though this risk lies primarily with inhalation and not ingestion through the food supply).  As the radioactive water pours into the Pacific Ocean, it will be carried away from Japan (a stroke of good fortune) into the heart of the Pacific Ocean (and towards California), where it will be diluted, though significant amounts of radioactive particles will be absorbed by wildlife near the spill.  According to the New York Times, the primary source (98%) of radioactive iodine-131 in humans is from the ingestion of radioactive foods (milk and dairy).  The body accumulates iodine in the thyroid, and as a result, the ingestion of radioactive iodine leads to its concentration in the thyroid and is well-known to cause thyroid cancer.  This raises the concern that fish or seaweed–common exports of the Japanese sushi industry–that had been exposed to radioactive iodine would pose a similar health risk.

Fortunately, fish are not prone to absorb iodine from the water, and any iodine that was absorbed by fish would purportedly decay within a couple of weeks. Seaweed, on the other hand, acts like a sponge to soak up iodine in massive amounts, which might raise concern for fresh seaweed being sold as a salad, but not for seaweed turned into nori for sushi rolls (a common export from Japan), since the radioactivity would again decay before the nori could be brought to market. Guess you can throw away those iodine pills after all.

Cesium, on the other hand, poses much more serious health risks.  Cesium accumulates in the tissues of fish, and as a result, concentrations of cesium in fish can be 100 times their surrounding waters. This concentration only becomes worse as fish eat other fish and the cesium travels up the food chain to larger predators like tuna, posing a serious radioactivity concern for tuna being exported from Japan.  Cesium is a metal, like mercury, and it lodges in the muscles because your body thinks it is potassium.  Yet unlike mercury, cesium passes through the body and does not remain there.  Like other forms of radioactivity, cesium is associated with higher risks of cancer.

For the majority of the population, radiation in fact poses its most serious danger in the local water supply, which, in Japan, has already been contaminated.  The most devastating effects of radiation are seen in children and pregnant women, as fetal development is characterized by a rapid reproduction and splitting of cells.  Radiation exposure, therefore, can cause genetic mutations and severe deformities in developing fetuses.  According to Chernobyl Heart, an award-winning documentary on the effects of radioactive fallout from the Chernobyl disaster, even today only 15-20% of Belorussian babies are born healthy.

While the fallout in Japan is unlikely to be as severe as in Chernobyl (the Japanese meltdown has been characterized by melting and leakage, whereas in Chernobyl, the nuclear fuel was vaporized and dispersed in the air), the Chernobyl disaster presents valuable information on the devastating health effects of radiation: babies born with their brains outside their skulls, partially formed limbs, mental retardation, and children with holes in the hearts.  For some devastating photos on the health effects of radiation caused by the Chernobyl disaster, check out this spectacular photo essay by Paul Fusco.

It is frighteningly obvious, therefore, that in Japan, radiation pollution raises serious health concerns for the general population. Given the devastatingly poor response to this disaster, it is clear that the Japanese government, and other governments for that matter, are currently incapable of dealing with nuclear fallout. The only way forward for Japan, therefore, seems to be to become the world’s expert in nuclear fallout management, or else forever live in the shadow of a disaster of its own making.