Effects of the Chernobyl disaster children of liquidators conceived after the accident, when compared to their siblings that were conceived before. However, this effect has diminished sharply over time. Soviet authorities started evacuating people from the area around Chernobyl only on the second day after the disaster (after about 36 hours). By May 1986, about a month later, all those living within a radius of the plant (about 116,000 people) had been relocated. This area is often referred to as the zone of alienation. However, significant radiation affected the environment over a much wider scale than this 30 km radius encloses. According to reports from
Chernobyl disaster the accident has meant that many cases that would previously have gone unnoticed (especially of cancer) are now being registered. The World Health Organization states, "children conceived before or after their father's exposure showed no statistically significant differences in mutation frequencies". This statistically insignificant increase was also seen by independent researchers analyzing the children of the Chernobyl liquidators. On farms in Narodychi Raion of Ukraine it is claimed that in the first four years of the disaster nearly 350 animals were born with gross deformities such as missing or extra limbs, missing eyes, heads or ribs, or deformed skulls; in