Rise in Cancers from Environmental Chemicals

Professor Dominique Belpomme, a medical oncologist from the University of Paris, has new research showing that environmental exposures to pesticides and other contaminants are now more significant as a cause of cancer than tobacco. He summarised his findings during the PAN Europe network members’ conference in Copenhagen. 

IARC, the International Agency for Cancer Research, now considers data showing environmental pollutants such as pesticides are more significant in causing cancer than previously thought. This is an important milestone for a team of French scientists who have challenged the orthodox notion that tobacco is still the main cause of cancer across all the industrialised nations. 

Primary prevention policies
‘It is now clear that these environmental factors account for the increased incidence of cancers in all industrialised countries,’ said Professor Dominique Belpomme, a medical oncologist and president of the French Association for Research on Treatments Against Cancer (ARTAC).
 ‘Public health policies in these countries must now focus on the relationship between environment and health, as the French Government is doing. Realistic primary prevention policies should be introduced with the aim of avoiding the deleterious factors which we introduce into the environment.’

Tobacco less important
Before his data had been published and accepted by the French scientific community, Professor Belpomme spoke at the PAN Europe network members’ conference in Copenhagen. In his speech, Professor Belpomme explained why tobacco is now being considered less significant as the main cause of cancer. 

In 1981, Sir Richard Peto and Sir Richard Doll, the famous British researchers, estimated that tobacco accounted for about 30% of mortality by cancer. But Professor Belpomme has calculated that in France, tobacco now only causes between 15 and 20% of new cases of cancer. Deaths from such cancers are between 18% and 22%. These figures would be similar in other industrialised countries, and Professor Belpomme argued that governments in these countries should now focus more on the relationship between the environment and health.

In France, deaths from cancer have doubled since the Second World War and now stand at 150,000 people each year. At the same time, cancer incidence has increased dramatically during the last 20 years and there are now 280,000 new cases a year. Cancers due to occupational exposure represent no more than 5% to 6% of cases. Genetic factors account for no more than 5% of cases, and it had been shown that some viral contaminations could explain the occurrence of 10% of the cases, including primary liver cancer, leukaemia and lymphoma. Natural and artificial radioactivity could account for another 10% of cancer cases, including soft tissue sarcoma, leukaemia and lymphoma.

Environmental pollution
‘These factors alone cannot contribute to the recent increase in cancer incidence. So, it is clear that environmental factors are involved, mainly through food and/or atmospheric pollution in cities, at home or at work.’ In France, between 70% and 80% of cancers are now due to environmental pollution from chemicals such as polycyclic aromatic hydrocarbons, polyvinyl chloride, some heavy metals, nitrates, nitrites, dioxins, some food additives and pesticides.

Some pesticides have been classified as carcinogenic by international organisations including the Environmental Protection Agency (EPA) of the US and the IARC based in Lyons, France (an agency of the World Health Organisation). 

‘Furthermore, an increasing number of epidemiological hot spot studies strongly suggest that pesticide exposure is associated with several types of cancers, including leukaemia, soft tissue sarcoma, brain tumours, testicular cancer and child cancers. The involvement of pesticides in the increased incidence of prostate or breast cancers has still to be determined.’

Professor Belpomme argued that the precautionary principle demands that pesticides classified as carcinogenic by IARC and the US EPA should be prohibited. The prohibition should cover US EPA groups L1 (likely to cause cancer at high doses) and L2 (likely to be carcinogenic to people) and groups I (carcinogenic to humans), IIA (probably carcinogenic to humans) and IIB (possibly carcinogenic to humans). 

Professor Belpomme represents PAN Europe on the European Commission’s Environment and Health Strategy technical working group on endocrine disruptors, which has concentrated on the integrated monitoring of endocrine disrupting chemicals: he has written a letter to the group chairman and other members pointing out the need to consider the cancer causing properties of these chemicals as well as their endocrine disrupting ones. 

Database of pesticide effects
Finally, Professor Belpomme explained that he is contributing to the French national anti-cancer programme agreed by President Jacques Chirac and run by the French health ministry. Professor Belpomme is in charge of the environmental part of the programme, and has already argued that pesticides should be a top priority. He asked PAN Europe to help by contributing to a ‘scientifically sound’ database linking pesticides to their health effects. To discuss his concerns further, Professor Belpomme and ARTAC have organised an international meeting on the links between cancer and the environment – examining the role of pesticides in particular – on 7 May this year in Paris.

Les grands défis de la politique de santé en France et en Europe, D Belpomme, Ecologie et Santé, Editions Librairie de Médicis, France, 2003. Ces maladies créées par l’homme. Comment la dégradation de l’environnement met en péril notre santé, D Belpomme and Bernard Pascuito, 2004.

Prof. Belpomme can be contacted at ARTAC, 57-59 rue de la Convention, 75015, Paris, France email artac@cerc.wanadoo.fr,