A New Finding British
cancer researchers have found that childhood leukaemia is caused by an infection
and clusters of cases around industrial sites are the result of population
mixing that increases exposure. The research published in the British Journal of
Cancer backs up a 1988 theory that some as yet unidentified infection caused
leukaemia—not the environmental factors widely blamed for the disease.
“Childhood leukaemia appears to be an unusual result of a common
infection,” said Sir Richard Doll, an internationally—known cancer expert who
first linked tobacco with lung cancer in 1950. “A virus is the most likely
explanation. You would get an increased risk of it if you suddenly put a lot of
people from large towns in a rural area, where you might have people who had not
been exposed to the infection.” Doll was commenting on the new findings by
researchers at Newcastle University, which focused on a cluster of leukaemia
cases around the Sellafield nuclear reprocessing plant in Cumbria in northern
England. Scientists have been trying to establish why there was more leukaemia
in children around the Sellafield area, but have failed to establish a link with
radiation or pollution. The Newcastle University research by Heather Dickinson
and Louise Parker showed the cluster of cases could have been predicted because
of the amount of population mixing going on in the area, as large numbers of
construction workers and nuclear staff moved into a rural setting. “Our study
shows that population mixing can account for the (Sellafield) leukaemia cluster
and that all children, whether their parents are incomers or locals, are at a
higher risk if they are born in an area of high population mixing,” Dickinson
said in a statement issued by the Cancer Research Campaign, which publishes the
British Journal of Cancer. Their paper adds crucial weight to
the 1988 theory put forward by Leo Kinlen, a cancer epidemiologist at Oxford
University, who said that exposure to a common unidentified infection through
population mixing resulted in the disease.
According to the passage, which of the following is true______
A．Most people believe childhood leukaemia is due to environmental factors. B．Population mixing best explains the cause of childhood leukaemia. C．Radiation has nothing to do with childhood leukaemia. D．Children born in a large town are at higher risk of leukaemia.
