Radioactivity
The effects of low level radiation, and in particular the effects of internal radioactive emitters, on human health are hotly debated. What is clear is that the safety standards governing radiation exposure have been growing increasingly rigid as our understanding of radiation has increased. However, powerful vested interests and pro-nuclear lobby groups continue to make this a challenging area to campaign on.
The chief radiological hazard from uranium 238 is alpha radiation. When inhaled or ingested, alpha radiation is the most damaging form of ionising radiation. However, as U238 decays into its daughter products thorium and protactinium, both beta and gamma radiation are released, increasing the radiation burden further. Therefore DU particles must be considered as a dynamic mixture of radioactive isotopes.
Inside the body alpha radiation is incredibly disruptive, it is estimated that chromosome damage from alpha particles is about 100 times greater than that caused by an equivalent amount of other radiation. The heavy, highly charged particles can punch holes in DNA and leave a trail of ionised free radicals in their wake, disrupting finely tuned cellular processes.
In one day, one milligram of pure DU can release 1,071,000 alpha particles. Each particle is charged with more than four million electron volts of energy; this goes directly into whichever organ or tissue it is lodged in. It only requires 6 to 10 electron volts to break a DNA strand in a cell and these emissions cover a sphere with a radius of between 7 and 20 cells.
Novel effects from internal emitters are highlighting the hazards posed by exposure to internal alpha radiation. This includes the Bystander Effect - whereby cells adjacent to those struck by alpha particles also exhibit signs of radiation damage, and Genomic Instability, where the descendents of radiation damaged cells show increased rates of mutations: the precursor to cancer growth.
Ionising radiation is a human carcinogen at every dose-level, not just at high doses; there is no threshold dose and any alpha particle can cause irreparable genetic damage.
The chief radiological hazard from uranium 238 is alpha radiation. When inhaled or ingested, alpha radiation is the most damaging form of ionising radiation. However, as U238 decays into its daughter products thorium and protactinium, both beta and gamma radiation are released, increasing the radiation burden further. Therefore DU particles must be considered as a dynamic mixture of radioactive isotopes.
Inside the body alpha radiation is incredibly disruptive, it is estimated that chromosome damage from alpha particles is about 100 times greater than that caused by an equivalent amount of other radiation. The heavy, highly charged particles can punch holes in DNA and leave a trail of ionised free radicals in their wake, disrupting finely tuned cellular processes.
In one day, one milligram of pure DU can release 1,071,000 alpha particles. Each particle is charged with more than four million electron volts of energy; this goes directly into whichever organ or tissue it is lodged in. It only requires 6 to 10 electron volts to break a DNA strand in a cell and these emissions cover a sphere with a radius of between 7 and 20 cells.
Novel effects from internal emitters are highlighting the hazards posed by exposure to internal alpha radiation. This includes the Bystander Effect - whereby cells adjacent to those struck by alpha particles also exhibit signs of radiation damage, and Genomic Instability, where the descendents of radiation damaged cells show increased rates of mutations: the precursor to cancer growth.
Ionising radiation is a human carcinogen at every dose-level, not just at high doses; there is no threshold dose and any alpha particle can cause irreparable genetic damage.
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Download the 2004 UK CERRIE Report (Committee Examing the Risks of Internal Radioactive Emitters)
Tougher action is needed to allow for new information about the risks from internal radiation. Uncertainties about the risks mean that in some cases we might be exposed to 10 times the risk previously thought, while in other cases the risk may be almost zero. Uncertainties in current methods of estimating risks from internal radiation require policy makers and regulators to adopt a precautionary approach when dealing with exposures to internal radiation, according to a Report published today by the Committee Examining Radiation Risks of Internal Emitters (CERRIE).2 October 2006 - ICBUW -
Radiation Dosimetry: Why Internal Emitters Are Different
When ionising radiation passes through biological tissue it generates reactive chemical species, which may subsequently interact with crucial biochemical processes and generate adverse biological effects. The science of radiation dosimetry seeks to relate these biological outcomes to the radiation energy absorbed by the tissues, the so-called absorbed dose.28 September 2006 - ICBUW
Address
ICBUW - International Coalition to Ban Depleted Uranium
Bridge 5 Mill - 22a Beswick Street - Ancoats - Manchester (UK) - M4 7HR
Telephone: +44 (0)161 273 8293 / 8283 - Fax: +44 (0)161 273 8293
email: info@bandepleteduranium.org
Bridge 5 Mill - 22a Beswick Street - Ancoats - Manchester (UK) - M4 7HR
Telephone: +44 (0)161 273 8293 / 8283 - Fax: +44 (0)161 273 8293
email: info@bandepleteduranium.org