Questions and Answers about Tritium

11. If it’s so dangerous why are there no deaths?

A.    Radioactive water or water vapour. It's not something in the water, but the water molecules themselves that are radioactive.

    Tritium is the radioactive isotope of hydrogen. That means tritium is unstable and gives off radiation when it disintegrates. In the environment, the most common kind of tritium is tritiated water - that is, water molecules in which one (or both) of their hydrogen atoms is radioactive.

Q.         Is it dangerous?

A.    Yes, tritium is hazardous when you drink it, eat it, breathe it in or you absorb it through your skin.

    Tritium is not considered an external hazard, but is an internal one. It has a radioactive half life of about 12 years which means it stays around in the environment for a long time. It has the unusual properties of extremely rapid transport in the environment, quick uptake by humans, fast exchange mechanisms with other hydrogen atoms, and the ability to bind with organic molecules during cell formation and cell metabolism.

Q.         What are the effects of exposure to tritium?

A.    Radiation causes cancers, congenital malformations and genetic effects

Tritium is a radionuclide and all radionuclides when ingested or inhaled give off radiation. Radiation is known to be a carcinogen, teratogen and mutagen, and these effects are thought to occur down to the lowest possible exposures.

Q.        Why is Greenpeace concerned about tritium in Canada?

A.     Huge amounts are pumped into Lake Huron and Lake Ontario every day from Canada's nuclear power stations. Huge amounts are released to the air, as well.

    Tritium discharges from Canadian reactors are by far the largest in the world from civil nuclear power stations. They are 100s to 1000s times greater than tritium discharges from other kinds of nuclear reactors.

Q.        Should I be concerned?

A.    The closer you live to a nuclear power station, the more you should inform yourself about tritium. Near them, all rivers, wells, vegetation and animals, including humans, have raised levels of tritium inside them.

    Tritium emissions to air result in all downwind matter containing hydrogen becoming tritiated to ambient levels. This results in people drinking, breathing and absorbing tritium-contaminated water, and eating tritium-contaminated food.

Q.     What do nuclear industry and nuclear regulators think?

A.    They think tritium isn't dangerous and that the amounts released are below health limits.

    The Canadian Nuclear Safety Commission and the nuclear industry rely on official models for estimating the radiation "doses" from tritium. These contain serious scientific inaccuracies and result in very low doses being estimated. These estimates allow the continued operation of nuclear power stations.

Q.    What do Government scientists think?

A.    Most toe the nuclear industry line.

    Government officials and politicians are advised on radiation matters largely by the nuclear industry and its regulators. Many independent scientists consider tritium to be more dangerous than is officially recognised. Over the years, the more scientists have learned about tritium, the more hazardous it has been perceived. Greenpeace thinks Government officials and politicians should consult more widely and listen to a balance of views on radiation matters.

Q.    How can I decide between differing scientific views? It’s too complicated.

A.    Yes, it's complicated, and we sympathise. To help, ask yourself whom you think is likely to be more precautionary - nuclear scientists or independent ones?

Of course, all scientists who work on radiation issues are concerned about public health, but there is a tendency for nuclear scientists not to be too critical about radiation's effects in public. An analogy is that if you worked in the coffee industry, you wouldn't publicise coffee's adverse effects. There are conscientious scientists in the nuclear field who remain concerned about aspects of tritium, but it's difficult for them to say much in public.

Q.        Why is Greenpeace raising this now?

A.    Because the Ontario Government is considering extended lives for nuclear reactors and even building more. Also because new health reports have been published in Europe and the US which pose more questions about tritium.

    Official Government committees in the UK have recently studied tritium and recommended that its doses should be doubled and that more research should be carried out.

See www.cerrie.org and www.hpa.org.uk/radiation/advisory_groups/agir/tritium_internal_dosimetry.htm

Q.    But doesn’t tritium occur naturally?

A.    At low levels, yes, but that doesn't justify making huge amounts more and releasing them near large populations.

    Background tritium is created in the upper atmosphere by cosmic ray bombardment. So low background tritium levels exist around the world. We can't do anything about these but we can decide not to add to them.

Q.    If it’s so dangerous why are there no deaths?

A.    Because no-one is counting them.

Initial epidemiology studies in the 1990s found raised levels of leukemia and congential malformations, but no follow-up studies were commissioned.

Q.    Isn’t Greenpeace just scaremongering because it’s anti-nuclear.

A.    It's true that Greenpeace has opposed nuclear power as being dangerous, uneconomic, and unsafe for many years. But do you think official UK Government reports on tritium would set out to "scaremonger", as you say?