You can't smell it, you can't taste it and you can't feel radioactive materials in the air. But exposure to it can affect the health seriously.

For normal adults, depending on the amount of radiation, exposure might cause cancer, premature aging, organ diseases or even acute poisoning which usually ends in death, explains Dr. Winfrid Eisenberg from IPPNW, a German working group on nuclear energy.

Depending on the amount of radiation, exposure can cause different diseases

He also points out that radiation is a particular threat to unborn children. The young embryos, especially in the first three months of pregnancy, are the most susceptible to radiation damage, much more than born children or adults, he says. "An embryo grows very fast and it means that cells are dividing all the time," he explains further. "These cells are more sensitive to the effects of radiation than older cells."

Eisenberg says even a very small elevation of radioactivity or ionizing radiation may be harmful to embryos or fetuses.

Different risks for unborn children

The stage of pregnancy and the amount of radiation are crucial. If radiation exposure occurs very early before the organs have developed (up to the eighth week), children may be born with deformations.

If the embryo is exposed to radiation in the second half of the pregnancy, after the organs have developed, the risk of damage drops. But it makes children more prone to developing leukemia in the first few years of life. Another risk is stillbirth, meaning the fetus dies in the uterus.

Different effects on children were seen after Chernobyl

Lena Edlund, associate professor at Columbia University, has done research on the effects prenatal exposure to Chernobyl radiation had on Swedish children. After the disaster in Chernobyl, due to the weather situation, contaminated dust was blown thousands of miles away to Sweden, making the country an affected area.

Edlund, along with two co-researchers, looks at the outcomes of children who were in utero during the time of the Chernobyl accident in April 1986. The results show that children who were exposed to radiation between eight and 25 weeks later suffered from lower IQ and lower school performance, depending on the amount of radiation.



She also explains that not only is the brain particularly sensitive, but it generally has difficulty regenerating after damage has been done.

Until now there has been no evidence that damage caused by radiation can be passed on to subsequent generations.

Women seem to be more sensitive to radiation

For pregnant women and breast feeding mothers, there has been some evidence showing that radiation may lead to breast cancer, says Dr. Roy Shore, chief of research at the Radiation Effects Research Foundation. Shore adds that people who come into contact with high doses of radiation, like people in Hiroshima and Nagasaki when the atomic bombs were dropped, can become sterile.

Some studies show that women might be more sensitive to nuclear radiation

Other studies, like Eisenberg's, come to the conclusion that women and girls might be more susceptible to radiation.

Although it is not yet clear in which stage the development of female embryos is harmed by radiation, Eisenberg’s organization is trying to change the norms used. The use of 'Reference Man', a hypothetical 20 to 30 yeard old Caucasian male in radiation protection regulations and guidelines, does not protect those most at risk, who are often women and children. Instead Eisenberg and co. demand that 'Reference Embryo' be used for all safety limits.

Iodine tablets have limited effect

While experts agree that iodine tablets, when taken by pregnant women before exposure, can help the fetus, they also point to their limited effect. They only protect the thyroid gland, but not any other organs. These tablets are supposed to fill the thyroid gland with normal iodine, so as to prevent any radioactive isotope Iodine-131 or Iodine-129 from entering.

Iodine tabletts, if taken before exposure, only protect the thyroid gland

Admitting that it is very hard to give advice at the moment, as the situation keeps changing, Eldund says it is important to observe the weather patterns to see how the contamination spreds. She also adds that it is best to stay indoors as much as possible and points to the danger of contaminated fresh food.

Because relatively few safety precautions can be taken, Eisenberg warns that pregnant women and families with young children should be the first ones who get the chance to leave the area. "They have to be as far away as possible from such a meltdown," he says.

Voluntary evacuation for pregnant women

Until now, the precise levels of radiation in Japan are still unknown, as they vary hour by hour. With reports saying they have reached around two hundred times more than the level people would normally face, Shore, who is based in Hiroshima, says that the reactors do not have the potential to release the amount of radioactive iodine and caesium as in Chernobyl.

The Japanese government has recommended the voluntary evacuation of pregnant women and pre-school age children within 80 kilometers of Fukushima. So far, more than 140,000 people have left the disaster area.

Author: Anggatira Gollmer

Editor: Grahame Lucas