WHO Report
Author's note: Provided in the following synopsis is a compilation in the form of statistics of the health effects directly attributed to the radiation fallout. Of course, as a result of this accident there was considerable psychological and political "fallout." On April 8-12, 1996, The International Atomic Energy Agency (IAEA) sponsored a conference summing up the consequences of the accident, not just from the radiation. Their conclusions and observations are available on the Web.

WHO Report - Health Consequences of the Chernobyl Accident

Results of the IPHECA pilot projects and related national programmes - Summary Report, 1995, ISBN 92 4 1561815

This booklet provides a summary of a larger report of the results of a WHO-sponsored International Program to monitor the Health Effects of the Chernobyl Accident (IPHECA) and thus represents some of the most comprehensive and accurate information compiled to date.

IPHECA Results in a Nutshell

Total radioactivity releases from the reactor was 200 times that of the combined releases from the atomic bombs dropped on Hiroshima and Nagasaki, mainly in the form of iodine-131, cesium-134, and cesium137.
Of these, the isotope with the greatest health impact is iodine-131 because it accumulates in the thyroid gland. Growing chldren are particularly susceptible because their thyroids are much more active.

Population Exposure Data

Average Exposure Rate per Year   Population Exposed         Action Taken
        > 5mSv	                      135000               all evacuated
        up to 5mSv                    270000             voluntary relocation
                                                        compulsory monitoring
        up to 2 mSv                   580000           special health monitoring
        up to 1mSv                   4000000           regular health monitoring

Non-Radiation Effects Psychological effects due to fear and the stress of dislocation (evacuees). The evacuation caused financial hardships, restrictions of diet, uncertainty regarding housing and employment. The tense situation causes considerable stress which, combined with the constant fear of health damage from the radioactive fallout, led to a rising number of health disorders being reported to local outpatient clinics. The immediate psychological impact was similar to that caused by an earthquake, fire, or other natural disaster. Finally, the study reports a large increase in a number of specific diseases involving the endocrine, nervous, digestive, and genitourinary systems. The study also reports increases in the incidence of mental retardation, behavioral, and emotional problems in exposed children. Present evidence does not suggest that these diseases are radiation-induced, but may have resulted from the considerable stress experienced.
Radiation Effects

Immediate Effects - Limited to reactor plant personnel and firefighters.

Two people died during the accident. 444 people were at the site and were exposed to large amounts of radiation. About 300 were admitted to hospitals and 134 were diagnosed with acute radiation sickness. 28 of these people died within 3 months. Of those who recovered, most continued with emotional or sleep disorders. 30% suffered from various medical disorders that reduced their ability to work. No clinical symptoms of acute radiation syndrome were seen in the people evacuated from the 30-km evacuation zone or in residents of affected areas.

Long-Term Effects -

Significant increases of childhood thyroid cancer have been measured in the region around the plant, particularly in the Gomel administrative district. The report includes the following table of data showing the increase in thyroid cancer rates.
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                Number of Cases Per Year
Country              1986   1987   1988   1989   1990   1991   1992   1993   1994   TOTAL
Belarus                2      4      5      7     29     59     66     79     82     333
Russian Federation     0      1      0      0      2      0      4      6     11      24
Ukraine                8      7      8     11     26     22     47     42     37*    208*

        Incidence per Million Children
Country             1986   1987   1988   1989   1990   1991   1992   1993   1994
Belarus              0.9    1.7    2.2    3.0     13     26     28     34     36
Russian Federation   0.0    2.0    0.0    0.0    4.0    0.0    8.0     12     22
Ukraine              0.7    0.6    0.7    0.9    2.2    1.8    3.9    3.5    3.1*        

* incomplete number
```
Usually, the thyroid can be succesfully removed so most of the victimns are expected to recover. Howver, more than 95% of the cases were reported to be highly invasive and the cancer spread to other soft tissues. In a few cases, the children died.

Other thyroid diseases, such as autoimmune thryroiditis, nodular goiter,, and hypothyroidism have been intensely studied, but show no reliable signs of increase.

Other Long-Term Effects
- An increase in the occurrence of some blood disorders to cesium-137 contamination
```
                                      Cases per Year
                           1979-1985                 1986-1993
Belarus                        97                       103       
Russian Federation             30                        36
Ukraine                        24                        32
```
  The death rate from these disorders showed no increase attributable to radiation. The morbidity rate in the uncontaminated region increased at the same rate as that in the contaminated region.
- The incidence of childhoof leukemia did not change significantly after the accident when compared with the period before 1986.
- The incidence of diseases of the oral mucosa and periodontal and dental tissues was almost identical among residents of the contaminated and uncontaminated regions in Belarus.