Nom original: Chernobyl.pdf
Ce document au format PDF 1.4 a été généré par / iText 2.0.0 (by lowagie.com), et a été envoyé sur fichier-pdf.fr le 03/09/2011 à 17:42, depuis l'adresse IP 90.60.x.x.
La présente page de téléchargement du fichier a été vue 1209 fois.
Taille du document: 44 Ko (1 page).
Confidentialité: fichier public
Télécharger le fichier (PDF)
Aperçu du document
Food. Environmental Health Criteria No. 70. Geneva:
World Health Organization, International Programme
on Chemical Safety.
http://www.who.int – IPCS (1994, 1999) Assessing Human
Health Risks of Chemicals: Derivation of Guidance Values for Health-based Exposure Limits. Environmental
Health Criteria Nos. 170 and 210. See also IPCS Workshop on Developing a Conceptual Framework for Cancer Risk Assessment, Lyon, France, February 16–18,
1999 (IPCS/99.6). Geneva: World Health Organization,
International Programme on Chemical Safety.
http://www.ipcsharmonize.org – International Programme
on Chemical Safety (IPCS) (2001) Guidance Document
for the Use of Data in Development of Chemical-Specific
Adjustment Factors (CSAFs) for Interspecies differences
and Human Variability in Dose/Concentration–Response
Assessment. Geneva: World Health Organization, International Programme on Chemical Safety.
See Cancer Chemotherapeutic Agents.
Amy Bickham Baird and Ronald K Chesser
& 2005 Elsevier Inc. All rights reserved.
The meltdown of Reactor IV at the Chernobyl nuclear power plant on April 26, 1986 was the worst
nuclear disaster in history. Radioactive fallout from
the accident impacted not only Ukraine and its residents, but countries along the path of the radiation
plume all the way to Scandinavia. A total of 31 people died as a result of the accident but the complete
extent of the health effects are unknown. Despite
obvious negative effects, some good came of the accident in terms of helping shape safety measures in
nuclear power plants, as well as furthering our understanding of the consequences of exposure to radiation. But what about the long-term effects of
exposure to radiation? Now, over 15 years after the
accident, we are able to obtain a clearer understanding of these long-term effects. Scientists have been
interested in the health effects of those exposed to
high amounts of radiation following the meltdown,
as well as effects on the nearby environment, where
there still remains a high level of contamination.
reached as high as 15 Gy, leading to the deaths of 29
persons (two died as a direct result of the explosion)
within 4 months. Exposure of adolescents to 131I in
Chernobyl fallout has contributed to elevated cases
of thyroid cancers in northern Ukraine and southern
Belarus. Thyroid cancers are usually treatable and
have not lead to substantial increases in deaths attributable to Chernobyl.
Dose rates rapidly declined subsequent to the
Chernobyl accident and ensuing fire. Most of the
isotopes released had short half-lives, so their energy
rapidly generated absorbed radiation doses. Ninetyeight percent of the isotopes released at Chernobyl
has now dissipated. The predominant radionuclides
remaining are 137Cs and 90Sr, each having half-lives
of B30 years. These isotopes, however, have high
biological affinities and are readily incorporated
into living tissues. Because of this affinity, the animals living in the regions near the reactor (Red Forest) are the most radioactive organisms living in
otherwise natural environments. Some rodents, for
example, are receiving up to 0.1 Gy day 1 from
cesium and strontium in their muscle and bone.
Documenting the doses received at Chernobyl is an
important step in performing empirical studies for
observing and noting the responses to exposure to
Dose rates in the regions surrounding Reactor IV
were highly variable due to distinct plumes of radioactive fallout released subsequent to the explosion.
The first plume, designated the Western Trace, yielded doses in excess of 6 Gy h 1 in some areas, resulting in the death of over 400 ha of pine (Pinus
sylvestris) forest. Radiation doses to firemen and reactor personnel exposed shortly after the explosion
Environmental and Genetic Impacts –
Living in a radioactive environment such as the areas
at Chernobyl could have many potential impacts on
the surrounding ecosystem, such as a reduction in
lifespan of resident species, increased cancer risks,
and a reduction in diversity (both genetic and species
diversity) to name a few.