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 phase" and would not dissolve for 800–1000 years. Guidelines for levels of radioiodine in drinking water were temporarily raised to 3,700 Bq/L, allowing most water to be reported as safe, and a year after the accident it was announced that even the water of the Chernobyl plant's cooling pond was within acceptable norms. Despite this, two months after the disaster the Kiev water supply was abruptly switched from the Dnieper to the Desna River. Meanwhile, massive silt traps were constructed, along with an enormous 30m-deep underground barrier to prevent groundwater from the destroyed reactor entering the Pripyat River. Bio-accumulation of