Download Title : Radioactivity and his consequences in our organism

Title : Radioactivity and his consequences in our organism
RESEARCHERS: Massamba Yannick Tran Antony
STATEMENT OF PURPOSE AND HYPOTHESIS:
How radioactivity can affect our body and causes mutation
We want to find how the radioactivity can causes diseases and mutations. We will take the
example of Chernobyl accident.
METHODOLOGY:
We will show that the radioactivity is composed of different ray (X ray and gamma ray)
This ray affect the cells of our body and affect them divisions genes.
We will take some examples in particularly Chernobyl’s one.
III. ANALYSIS OF DATA:
Sources:
www.cbu.edu/~jholmes/P252/Nuc.html
www.bbc.co.uk/dna/h2g2/alabaster/A661727
The Alpha radiation is the most dangerous form of radiation, since the alpha-particles (Helium
nuclei) are very fast (5-10% of light speed) and are relatively massive compared to electrons and
photons. Alpha radiation is responsible for most of the damage of DNA in living cells, the main
reason for the cancer cases and occurrence of mutations after fallout. Luckily it only acts on a very
short range (in the order of microns) and can be blocked by a sheet of paper. Incorporation of alpha
emitters though eg, from fallout dust, will cause a long-term exposure to alpha radiation, which can
cause serious harm. Sadly, many decay processes yield Radon, a gaseous alpha-emitter (about four
days half-life), that can be inhaled. Radon decays to Polonium (a solid metal) also an alpha-emitter
that will stay in the lungs.
Beta radiation penetrates things to a depth of about a centimetre. It is therefore more difficult to
block2, but it has not such a high ionisation potential (compared to alpha radiation).
Gamma Radiation has little ionisation potential3 compared to the alpha and beta radiations but it
can penetrate many metres of matter. For that reason it cannot be readily blocked, which is the most
dangerous thing about gamma radiation. Exposition to gamma radiation is not necessarily tied to
the presence of radioactive elements.
Neutron radiation is particularly dangerous since it combines long range penetration and high
ionisation potentials.
ACUTE DOSE EFFECTS: (dose obtained within a few weeks)
20,000 mrems: measurable transient blood changes
150,000 mrems: acute radiation sickness
200,000 mrems: death in some people
350,000 mrems: death in 50% of people;
(LD 50/60 = lethal dose that kills 50% within 60 days is between 4-6 Gy)
localized (not whole-body doses) for cancer treatment:
10,000,000 mrems
LONG TERM EFFECTS
At the cellular level, a dose of 1 mGy of ionizing radiation gives 1 "hit" on a cell. (So the
background radiation gives about 2 hits per year to each cell.) A "hit" on a cell can cause DNA
damage that leads to cancer later in life. There are other causes of DNA damage, a relatively large
amount from normal chemical reactions in metabolism. There are four other responses by cells to
"hits". 1. The body may be stimulated to produce de-toxifying agents, reducing the damage done by
the chemical reactions of metabolism. 2. The body may be stimulated to initiate damage repair
mechanisms. 3. The cells may kill themselves (and remove the cancer risk) by a process called
apoptosis, or programmed cell death (a regular process that happens when the cell determines that
things are not right). 4. The body may be stimulated to provide an immune response that entails
actively searching for defective cells - whether the damage was done by the radiation or by other
means.
Chernobyl exemple:
of pre-accident data to work with and the controversial nature of the issue itself. What is
more stunning are the vast differences in estimates of health effects.
The U.N.'s World Health Organization (WHO) estimates, for example, that so far only
about 50 people have died as a direct result of Chernobyl, and a few hundred cases of
cancer--mostly thyroid--likely will lead to additional deaths.
But the WHO's estimates are so much lower than every other estimate that it is difficult to
take them seriously. It appears that the WHO has only accepted deaths which can provably
be laid to Chernobyl radiation.
But radiation doesn't carry a silver bullet: when someone dies of cancer or, as they call it in
Ukraine, Chernobyl AIDS--a weakness and general suppression of the immune
system--there is no banner which rises up and says "Chernobyl killed me."
On the high end, a Ukrainian victims group claims 150,000 already dead, the Ukrainian
Ministry of Public Health in April 1995 said 125,000 already dead. Both estimates seem
high, and indeed, include deaths of elderly persons who might reasonably have been
expected to die over the past ten years in any event. [However, contrary to nuclear industry
propaganda, these numbers do not include everyone who died in Ukraine from 1986-95
from any cause, including car accidents. If so, Ukraine would probably have the lowest
death rate in the industrialized world. Instead, it has one of the highest. Indeed, Belarus and
Ukraine may be the only two nations on the planet whose death rate exceeds the birth rate].
Other estimates range from several thousand, mostly "liquidators" who have died, to an
estimate by Greenpeace Ukraine of 32,000 now dead. Greenpeace derived their figure by
examining death rates from illnesses before and after the accident. Their research was solid
enough that Yuri Shcherbak, the Ukraine Ambassador to the United States, accepts that
estimate in the April 1996 issue of Scientific American.
The economic cost to Belarus, Ukraine and Russia has been even greater--more on that in a
moment. But often overlooked as a Chernobyl consequence is the effect diversion of huge
portions of these countries' budgets has had on public health and mortality. Ukraine, for
example, has been spending 5-7% of its annual budget on Chernobyl-related activities;
Belarus has been spending 20% and more. Had that funding been available instead for
public health and welfare improvements, it is unquestionable that both countries would be
much better off, and very likely that the mortality rates would be far lower.
First, consider that Chernobyl was in a very remote area, 80 miles from Kiev to the south
and 80 miles from Gomel to the north. Then consider that Indian Point is only 35 miles
from Manhattan; Limerick a similar distance from Philadelphia; Zion even closer to
Chicago; Wolf Creek and Callaway in the center of our nation's agricultural heartland.
Much has been written this tenth anniversary about the "psychic damage" attributed to
Chernobyl. Many articles have implied that this is the major, perhaps only real damage
from the accident.
Make no mistake, the psychic damage is real. People in Ukraine, Belarus and Russia are
scared. They are afraid to have children, afraid of dying young, afraid of another
Chernobyl. Western scientists, especially those affiliated with the nuclear industry, dismiss
this as "radiophobia." In fact, it is an entirely rational response to the enormous
consequences that do exist and to a government that lied unforgivably to them once and
may do so again.
The people of Eastern Europe do not like living in polluted environments any more than we
do. But to call them "phobic" because they react humanly to those environments is the
ultimate insult. The stakes are very real and high and, as usual, the people know best
Conclusion : We showed that the radioactivity would cause mutations and cancers. The
radioactivity sends rays on the cells which undergo mutations which affect the division and grows
genes and causes malfunctions. They multiply without any orders and becomes cancers.
Application:
We show that the radioactivity is very dangerous so we must protect from them
The invisible ray is the most dangerous
The example of Chernobyl accident is for makes this accident doesn’t produce again.