Latent Effects Plants and Animals

Total radiocesium-137 deposited in soils at Chernobyl sites 2-15 km from the reactor was estimated at 1,660,000 Bq/m, mainly as insoluble fuel particles. The half-time persistence of Cs in surface soils 0-2 cm in depth decreased from 9 years in 1987 to 3 years in 1994 but the residence time of this isotope increased with increasing depth over time. This increase in deeper layers is attributed to the progressive fixation of radiocesium by clay minerals of the soil. 

In 1992, bacteria were isolated from soils within 30 km of the power plant. Sporeforming bacilli collected nearest to the power plant were more resistant to X-radiation, ultraviolet radiation, and 4-nitroquinoline 1-oxide 

In June 1991, male bam swallows (Hirundo rustica) collected within 50 km of Chernobyl - when compared to control areas 100 km distant and with museum samples from both 

In 1991, five years after the accident, a female root vole (Microtus oeconomus) with an abnormal karyotype (reciprocal translocation) was found within the 30-km radius of the Chernobyl nuclear power plant. These chromosomal aberrations were probably inherited and did not affect the viability of vole populations. Population density of Chernobyl rodents in 1988-89 was about twice that predicted from previous cycles, and was attributed, in part, to increasing radioresistance and abundance of their food supplies. In 1994-95, the diversity and abundance of the small mammal population (12 species of rodents) at the most radioactive sites at Chernobyl were the same as reference sites. Rodents from the most radioactive areas did not show gross morphological features other than enlargement of the spleen. There were no gross chromosomal 

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