Misinformation breeds discrimination. As if it wasn’t enough to experience the trauma of a nuclear bomb, many hibakusha (atomic bomb survivors) also faced appalling discrimination.

It appears their children and grandchildren still do — as do those who were caught up in the Fukushima No. 1 nuclear disaster in 2011.

Problems arise because the general public is not properly informed about radiation. Stories in newspapers often exaggerate the risks and fears surrounding radiation, as do lobby groups opposed to nuclear energy.

I’ve been thinking about this when reading some of the first-hand accounts of nuclear war from surviving hibakusha.

Shimako Yamaguchi, 94, recounted her memories of the Nagasaki bomb to the Asahi Shimbun. She’s been plagued by nightmares about the dying people she had to leave behind.

Crawling across a bridge covered in bodies on the morning of Aug. 9, 1945, she had to free herself from a hand that grasped her ankle. Sometimes, guilt-ridden, she still feels the grip of that hand.

However, she said, throughout her life she’s been called a marugen (“nukey”), even in hospitals when she’s gone for checkups.

Hiroshima resident Shizuoka Abe, 18 at the time of the bomb and now 88, told the British Broadcasting Corp. that her children were bullied. They were called “A-bomb children” and faced discrimination.

Perhaps even more troubling, misinformation may still cause discrimination, fear and suffering today. I heard from a friend of a friend in Hiroshima, a granddaughter of a hibakusha, that she was afraid to have children in case they had genetic problems. I was shocked by this — the woman herself is fine but she was still worried about her genes. She should not be concerned. Several studies have shown that the children and grandchildren of hibakusha do not have any increased risk of genetic problems. It’s horrifying that people should still be worried about this; the general public should be reassured that they are OK.

In a paper published earlier this month in The Lancet medical journal, professor Kenji Kamiya of Hiroshima University and colleagues reported on the long-term health impact of radiation exposure from Hiroshima and Nagasaki. Kamiya’s team looked at evidence from a life span study that followed 94,000 atomic bomb survivors from 1950 (five years after the bombings) to the current day.

Yes, they found that survivors of the bombs face an increased lifetime risk of cancer. The risk was found to be proportional to dose for “solid cancers” — all cancers other than leukemia — and people exposed as children had a higher risk.

However, hereditary effects have not been detected. In other words, the children of hibakusha are not at any greater risk of developing cancer during their lives.

In a 2003 study conducted by Dale Preston of Hirosoft International Corp., researchers found that hibakusha had a 10.7 percent greater risk of developing a solid cancer than other Japanese who were not exposed to radiation.

In addition, the Radiation Effects Research Foundation found that a person who receives a whole-body dose of radiation will carry a cancer risk that is less than five times that of an unexposed individual.

It is uncontroversial to conclude, therefore, that the psychological effects of radiation exposure may be worse than the actual physiological effects. Certainly, the psychological stigma seems to have been worse for a number of descendants of hibakusha and for people living near the Fukushima nuclear power plant.

Koichi Tanigawa of Fukushima Medical University agrees that the worst outcome of the disaster was the psychological problems it caused.

“Although the radiation dose to the public from Fukushima was relatively low, and no discernible physical health effects are expected, psychological and social problems, largely stemming from the differences in risk perceptions, have had a devastating impact on people’s lives,” Tanigawa wrote in findings published in The Lancet.

Tanigawa’s colleague, Akira Ohtsuru, also at Fukushima Medical University, has also published a paper that addresses concerns about mental health in the wake of a nuclear accident.

“One of the key tasks of the health services is to reliably communicate that in most nuclear accidents very few people are exposed to a life-threatening dose of radiation,” Ohtsuru wrote.

He also wrote that “screening for mental illness in residents relocated from their homes and providing mental health care will be essential.”

It’s not really surprising that the obvious physical effects of radiation exposure are the ones that doctors have focused on over the years. First the immediate effects of exposure to radiation, then the potential increased risk of cancer.

Radiation is invisible and that’s one of the reasons it is so feared. However, the psychological effects of exposure — even of small, harmless amounts — are hard to see, too. Even reading the accounts of the hibakusha can be harrowing. Nothing most of us have experienced comes close. It is vital that their stories are told so people never forget what they went through.

We can now, in the month of the 70th anniversary of the nuclear bombing of Hiroshima and Nagasaki, at least acknowledge the psychological burden carried by those caught up in nuclear accidents — especially those living around Fukushima — to make their internal suffering visible. This is the conclusion of Kamiya’s paper.

“Psychosocial problems in Fukushima have a devastating effect on people’s lives,” he wrote. “In addition to the natural science of radiation effects, psychosocial studies should be integrated into recovery planning after nuclear accidents such as that at Fukushima.”

Rowan Hooper is the news editor of New Scientist magazine. The second volume of Natural Selections columns translated into Japanese is published by Shinchosha. The title is “Hito wa Ima mo Shinka Shiteru” (“The Evolving Human”). Follow Rowan on Twitter @rowhoop.