Pollution could be cause of child leukaemia rise
Environmental pollution such as pesticides could be a causal factor in the rise in incidences of childhood leukaemia by affecting developing foetuses, scientists have said this week.Alan Preece, Professor of medical physics at the University of Bristol presented research to the Childhood Leukaemia conference showing that harmful environmental agents can cross the placenta to reach the developing foetus. This makes unborn children particularly sensitive to the effects of exposure to environmental agents.
The incidence of childhood leukaemia in Britain has increased dramatically during the last century, mainly affecting the under five age group. Causes are not well understood, but environmental factors are thought to play a major role.
Preece and his team set out to determine the extent of placental transfer of various pollutants through a series of bio-distribution measurements and ex vivo experiments using donated human placentas. They found reasonable correlation between the placental transfer data from different models, allowing preliminary calculations of dose to foetal organs.
"We found that foetal organ concentrations can exceed those of the mother which may have implications due to the increased sensitivity of the foetus. The exact levels are as yet unknown, but we do know that childhood leukaemia is initiated in utero and this could well be a factor in the initiation. Consideration must now be given to the likely estimates," Preece said.
Leukaemia, or blood cancer, is the most common cause of cancer in children and accounts for nearly a third of all cases. Cases have risen from about 10 per million population in England and Wales in 1911-1915, to about 46 million by the year 2000.
One explanation for the rise in incidences given at the conference is the rise in use of chemicals and other environmental agents that did not exist at the start of the century.
The conference has been organised by Children with Leukaemia, a UK charity.
By David Hopkins