Are radiation effects transmitted intergenerationally?

In this post I look at recent findings on whether or not radiation leads to genetic effects that may be transmitted intergenerationally. In other words, is there evidence that the offspring of someone who has been exposure one or several generations before will suffer health impacts as a result of the radiation?

My main reason for asking this is a recent article that has just been published in the journal Epidemiology and has been introduced in The Ecologist HERE.

What is the main point of the article?

The UK conducted Nuclear atmospheric weapons tests at  Christmas Island (now Kiribati) and Malden Island in the Pacific and in Australia between 1952 and 1958; there were clean-up operations until 1967.

At that time still, all these tests were undertaken in mid-air, implying fallout. The author of the article, Chris Busby, sent questionnaires to the veterans who were at those nuclear test sides during those years and asked questions related to offspring and their health. Overall there were 280 valid responses, which included 605 chilcren and 749 grandchildren. The results from that group were then compared to a so-called control group of UK veterans and general UK health information.

The results were as follows:

In conclusion, we argue that the results of this study support the belief that involvement in the Nuclear Tests caused increased rates of genetic-based illness in both the children and grandchildren of veterans. This may be by induction of trans-generational genomic instability. We suggest the cause is internal exposure to radioactive contamination at the test sites.

Overall, the findings show that “bomb test veterans’ children were 8.4 times more likely to have children with congenital malformations than the controls.”

That’s pretty bad news, especially if the health impacts are passed down through multiple generations. Of course, these kinds of secondary impacts or costs are unlikely to figure in any Cost-Benefit Analysis related to nuclear technology or incidents.

But then one starts to wonder. Wait, isn’t there a much better way to study this? That sample is not that small, but neither very large, and not all veterans from nuclear tests did complete the questionnaire so there may be some selection bias that tends to bias the frequency of children with health issues upwards.

Obviously, a better place to study this would be Hiroshima and Nagasaki, and one would imagine a wealth of research done on intergenerational transmission from parents that lived in both cities in 1945. But, surprisingly, it is very difficult to come across useful studies.

Most studies look into the impact of radiation in utero, that means when radiation hit a pregnant woman, and then analyzed the health impact on the child. These studies tend to show a variety of health impacts, from mental retardation to increased cancer rates or significantly higher perinatal morbility.

But what is clearly important as well is to know whether these health impacts may linger around across multiple generations. And here it is extremely difficult to study this. For example, in the case of Chernobyl, Hiroshima or Nagasaki, one would have to obtain data on people exposed to the radiation at the time of the incidents, and then followed up on the health impacts of their children that were not exposed in utero, and were born in regions different from those with higher radiation levels. This requires studies on something called transgenerational genomic instability.

Transgenerational genomic Instability basically means that genomic instability can be transferred to one’s children and their children, thus over potentially many generations. Genomic Instability means that cells which were e.g. damaged via radiation may switch on a mechanism that tells its descendents and potentially other cells around it to mutate, for potentially many generations to come.

Evidence for transgenerational genomic instability mostly comes from studies on fish or mice, but also for children of parents that were affected by Chernobyl’s accident. In addition to this first evidence from Chernobyl, there is now this new important paper that shows an increase in genetic-based illnesses of offspring from veterans that participated in atomic bomb tests.

Though studies on transgenerational genomic instability are still limited in number, they tend to indicate that radiation effects may linger around across generations, and thus already small doses of radiation may induce transgenerational genomic instability. In this case future Cost-Benefit Analysis (of e.g. nuclear power plants) has to integrate not only the impact of radiation on those exposed at an incident, but also the transgenerational impacts.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: