The Chornobyl accident and cognitive functioning: A follow-up study of infant evacuees at age 19 years

Background. The cognitive and academic outcomes of infants exposed to radiation after the meltdown at Chornobyl have been intensely debated. Western-based investigations indicate that no adverse effects occurred, but local studies reported increased cognitive impairments in exposed compared with non-exposed children. Our initial study found that at age 11 years, school grades and neuropsychological performance were similar in 300 children evacuated to Kiev as infants or in utero compared with 300 classmate controls, yet more evacuee mothers believed that their children had memory problems. This study re-examined the children's performance and academic achievement at age 19 years. Method. In 2005-2006, we conducted an 8-year follow-up of the evacuees (n=265) and classmate controls (n=261) assessed in Kiev in 1997. Outcomes included university attendance, tests of intelligence, attention, and memory, and subjective appraisals of memory problems. Scores were standardized using a local population-based control group (n=327). Analyses were stratified by parental education. Results. Evacuees and classmates performed similarly and in the normal range on all tests, and no differential temporal changes were found. The results were comparable for the in utero subsample. The rates of university attendance and self-reported memory problems were also similar. Nevertheless, the evacuee mothers were almost three times as likely to report that their children had memory problems compared with controls. Conclusions. Chornobyl did not influence the cognitive functioning of exposed infants although more evacuee mothers still believed that their offspring had memory problems. These lingering worries reflect a wider picture of persistent health concerns as a consequence of the accident.