Study: Leukemia Rates in Children Elevated Near Nuclear Facilities
Leukemia rates in children and young people up to the age of 25 are elevated near nuclear facilities, but no clear explanation exists to explain the rise, according to a research review published in the July issue of European Journal of Cancer Care. Researchers at the Medical University of South Carolina carried out a sophisticated meta-analysis of 17 research papers covering 136 nuclear sites in the UK, Canada, France, the United States, Germany, Japan, and Spain and found that death rates for children up to the age of nine were elevated by between five and 24 percent, depending on their proximity to nuclear facilities, and by two to 18 percent for those through age 25. Incidence rates were increased by 14 to 21 percent in zero to nine year olds and seven to 10 percent in zero to 25 year olds.
"Childhood leukaemia is a rare disease and nuclear sites are commonly found in rural areas, which means that sample sizes tend to be small," says lead author Dr. Peter J. Baker in the journal. "The advantage of carrying out a meta-analysis is that it enables us to draw together a number of studies that have employed common methods and draw wider conclusions." Eight separate analyses were performed--including unadjusted, random and fixed effect models--and the figures they produced showed considerable consistency. But the authors point out that dose-response studies they looked at--which describe how an organism is affected by different levels of exposure--did not show excess rates near nuclear facilities.
"Several difficulties arise when conducting dose-response studies in an epidemiological setting as they rely on a wide range of factors that are often hard to quantify," explains Baker. "It is also possible that there are environmental issues involved that we don't yet understand. . . . Several hypotheses have been proposed to explain the excess of childhood leukaemia in the vicinity of nuclear facilities, including environmental exposure and parental exposure. Professor Kinlen from Oxford University has also put forward a hypothesis that viral transmission, caused by mixing populations in a new rural location, could be responsible. It is clear that further research is needed into this important subject."