17/08/2005 - Childhood cancers strongly linked to air pollution in early life

Professor Knox's latest findings of significantly increased incidence of childhood cancer close to sources of vehicle exhaust pollution is in line with his own previous findings as well as an existing body of laboratory research indicating that vehicle exhaust pollution contains a range of known cancer causing agents. It is clear from these results that vehicle exhaust pollution could be a major causal factor in the incidence of childhood leukaemia in the UK.

Childhood cancers are strongly linked to pollution from engine exhausts, concludes research in the Journal of Epidemiology and Community Health.

The postal addresses of 22,500 children who had died of cancer in Britain between 1955 and 1980 were linked to emissions hotspots for specific chemicals. These were identified from published maps of atmospheric pollution levels.

The chemicals included carbon monoxide, particulate matter, nitrogen oxides, 1,3-butadiene, benzene, dioxins, benzo(a)pyrene, and volatile organic compounds.

Emission sources, including hospitals, bus/train stations, heavy transport hubs, and oil installations, were located using maps and information downloaded from the internet.

The expected deaths from childhood cancer were plotted against the actual deaths, and the postcodes where they had been born, lived, and died were used to calculate distances from the particular hotspots and emissions sources.

The calculations revealed an excess risk of cancer for children living within 0.3 kilometres of a chemical emissions hotspot and within 1 km of an emissions source, such as a transport hub.

1,3-butadiene and carbon monoxide, both of which are produced by vehicle exhausts, and particularly diesel engines, were among the primary culprits, the findings suggested.

When combined with close proximity to an emissions source, such as a bus or coach station, a child was at 12 times the risk of dying from cancer.

The author suggests that the exposure of a child in the womb and soon after birth to atmospheric pollutants is likely to be the critical period. And he goes on to say that accepted atmospheric safety levels for 1.3-butadiene in the workplace are probably unlikely to protect unborn children from developing cancer. More controls should be placed on the sources of emission, he says.

Despite response statements from scientists from the Leukaemia Research Fund and Cancer Research UK dismissing the importance of this work, there is actually far more evidence linking air pollutants and EMFs to the incidence of childhood leukaemia than there is evidence of a causal link with infections.

This is confirmation that air pollution is a causal factor in the initiation of childhood cancers. Professor Denis Henshaw and his team have shown that toxic aerosols that have been charged by corona electrons given off by high voltage powerlines are more likely to be retained in the lung and airways and enter the bloodstream. If their work is confirmed, air pollution in conjunction with powerlines could be a deadly combination. See here for more information on this research (Corona Ions section).

Contact:
Professor George Knox, emeritus professor, University of Birmingham, Birmingham, UK