Location of Chernobyl nuclear power plant The abandoned city of Pripyat with the Chernobyl facility visible in the distance The disaster began during a systems test on 26 April at reactor 4 of the Chernobyl plant near Pripyat and in proximity to the administrative border with Belarus and the Dnieper River.
While the effective doses of most of the residents of the contaminated areas are low, for many people, doses to the thyroid gland were large from ingestion of milk contaminated with radioactive iodine. Individual thyroid doses ranged from a few tens of mGy to several tens of Gy.
Apart from the people exposed to high levels of radioactive iodine mentioned above, only those liquidators who worked around the stricken reactor in the first two years after the accidentthe evacueessome of whom received doses well in excess of mSv, and the residents of the highly contaminated SCZsreceived doses significantly above typical natural background levels.
For comparison, the high radiation dose a patient typically receives from one whole body computer tomography CT scan is approximately equivalent to the total dose accumulated in 20 years by the residents of the low contaminated areas following the Chernobyl accident.
Thyroid cancer A large increase in the incidence of thyroid cancer has occurred among people who were young children and adolescents at the time of the accident and lived in the most contaminated areas of Belarus, the Russian Federation and Ukraine.
This was due to the high levels of radioactive iodine released from the Chernobyl reactor in the early days after the accident.
Radioactive iodine was deposited in pastures eaten by cows who then concentrated it in their milk which was subsequently drunk by children. This was further exacerbated by a general iodine deficiency in the local diet causing more of the radioactive iodine to be accumulated in the thyroid.
Since radioactive iodine is short lived, if people had stopped giving locally supplied contaminated milk to children for a few months following the accident, it is likely that most of the increase in radiation-induced thyroid cancer would not have resulted.
In Belarus, the Russian Federation and Ukraine nearly 5 cases of thyroid cancer have now been diagnosed to date among children who were aged up to 18 years at the time of the accident.
While a large number of these cancers resulted from radiation following the accident, intense medical monitoring for thyroid disease among the affected population has also resulted in the detection of thyroid cancers at a sub-clinical level, and so contributed to the overall increase in thyroid cancer numbers.
Fortunately, even in children with advanced tumours, treatment has been highly effective and the general prognosis for young patients is good.
However, they will need to take drugs for the rest of their lives to replace the loss of thyroid function. Further, there needs to be more study to evaluate the prognosis for children, especially those with distant metastases. It is expected that the increased incidence of thyroid cancer from Chernobyl will continue for many years, although the long-term magnitude of the risk is difficult to quantify.
Leukaemia and non-thyroid solid cancer Ionizing radiation is a known cause of certain types of leukaemia a malignancy of blood cells. An elevated risk of leukaemia was first found among the survivors of the atomic bombings in Japan some two to five years after exposure.
Recent investigations suggest a doubling of the incidence of leukaemia among the most highly exposed Chernobyl liquidators. No such increase has been clearly demonstrated among children or adults resident in any of the contaminated areas.
From the experience of the Japanese bomb survivors it is possible that a large proportion of the leukaemia cases that could be linked to Chernobyl have already occurred, now that 20 years have passed since the accident. However, further studies are needed to clarify this.
While scientists have conducted studies to determine whether cancers in many other organs may have been caused by radiation, reviews by the WHO Expert Group revealed no evidence of increased cancer risks, apart from thyroid cancer, that can clearly be attributed to radiation from Chernobyl.
Aside from the recent finding on leukaemia risk among Chernobyl liquidators, reports indicate a small increase in the incidence of pre-menopausal breast cancer in the most contaminated areas, which appear to be related to radiation dose.
Both of these findings, however, need confirmation in well-designed epidemiological studies. The absence of demonstrated increases in cancer risk — apart from thyroid cancer — is not proof that no increase has occurred.
Based on the experience of atomic bomb survivors, a small increase in the risk of cancer is expected, even at the low to moderate doses received.
Such an increase, however, is expected to be difficult to identify. Among them, 28 persons died in due to ARS. Other liquidators have since died but their deaths could not necessarily be attributed to radiation exposure. An increased number of cancer deaths can be expected during the lifetime of persons exposed to radiation from the accident.
Since it is currently impossible to determine which individual cancers were caused by radiation, the number of such deaths can only be estimated statistically using information and projections from the studies of atomic bomb survivors and other highly exposed populations.
It should be noted that the atomic bomb survivors received high radiation doses in a short time period, while Chernobyl caused low doses over a long time. This and other factors, such as trying to estimate doses people received some time after the accident, as well as differences in lifestyle and nutrition, cause very large uncertainties when making projections about future cancer deaths.
In addition, a significant non-radiation related reduction in the average lifespan in the three countries over the past 15 years caused by overuse of alcohol and tobacco, and reduced health care, have significantly increased the difficulties in detecting any effect of radiation on cancer mortality.
However, there are uncertainties concerning the magnitude of the effect, particularly at doses much lower than about mSv. The Expert Group concluded that there may be up to 4 additional cancer deaths among the three highest exposed groups over their lifetime liquidators; evacuees and the residents of the SCZs.
Predictions, generally based on the LNT model, suggest that up to 5 additional cancer deaths may occur in this population from radiation exposure, or about 0.WHO Expert Group report "Health Effects of the Chernobyl Accident and Special Health Care Programmes: Report of the UN Chernobyl Forum Health Expert Group, Editors Burton Bennett, Michael Repacholi and Zhanat Carr, World Health Organization, Geneva, The one process ongoing that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats.
Like the Chernobyl disaster, the Fukushima accident has resulted in cascading crises with impacts on public health, the environment, food safety, and psychosocial effects throughout the world. Chernobyl disaster, the populations affected at the time, whether by being displaced or exposed to radiation, have sustained neuropsychological consequences and .
THE FOOD LAB Helping to protect children and the community, by testing for radioactive contamination in food, and the environment. Listed here, are the latest International food detection reports for radioactive isotope contamination.
environmental remediation and special health care programmes, and to suggest areas in which further research is required. The Forum was created as a contribution to .