Leukemia in Children Exposed to Multiple Risk Factors

Abstract

The association between four factors —mother's irradiation before conception, in utero irradiation of the child, previous history of reproductive wastage, and early childhood virus diseases — was studied in children one to four years old. A simple rise in the number of factors did not consistently increase the risk for leukemia. Children with irradiation but without either of the pathologic conditions did not show a greater risk for leukemia, nor did those with the pathologic conditions but without irradiation. However, children exposed to two radiological factors who also had a history of one pathologic event had a significantly increased risk (2.69), as did those with a history of two pathologic factors who had also been exposed to one of the irradiation factors (3.36). The highest risk was 4.64 for children exposed to all four factors. Therefore, only when there was a concordance of the two types of events, irradiation and pathologic, was the risk for leukemia significantly greater.