Title: |
The multitude and diversity of environmental carcinogens
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Resource Type: |
document --> technical publication --> journal article
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Country: |
France
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Year: |
2007 |
Availability: |
Environ Res. 2007 Aug 8
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Author 1/Producer: |
D Belpomme
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Other Authors/Producers: |
P Irigaray , L Hardell , R Clapp , L Montagnier , S Epstein , A J Sasco
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Author / Producer Type: |
University research group / research institute
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EUGRIS Keyword(s): |
Contaminated land-->Contaminants-->Heavy metals Contaminated land-->Contaminants-->Others Contaminated land-->Contaminants-->PAH Contaminated land-->Risk assessment-->Toxicological information Diffuse pollution-->Contaminants-->Contaminants overview Diffuse pollution-->Contaminants-->Hydrocarbons Diffuse pollution-->Contaminants-->Persistent Organic Pollutants Diffuse pollution-->Contaminants-->Pesticides Diffuse pollution-->Diffuse pollution overview
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Short description: |
We have recently proposed that lifestyle-related factors, screening and aging cannot fully account for the present overall growing incidence of cancers. In order to propose the concept that in addition to lifestyle related factors, exogenous environmental factors may play a more important role in carcinogenesis than it is expected, and may therefore account for the growing incidence of cancer, we overview herein environmental factors, rated as certainly or potentially carcinogenic by the International Agency for Cancer Research (IARC). We thus analyze the carcinogenic effect of microorganisms (including viruses), radiations (including radioactivity, UV and pulsed electromagnetic fields) and xenochemicals. Chemicals related to environmental pollution appear to be of critical importance, since they can induce occupational cancers as well as other cancers. Of major concerns are: outdoor air pollution by carbon particles associated with polycyclic aromatic hydrocarbons; indoor air pollution by environmental tobacco smoke, formaldehyde and volatile organic compounds such as benzene and 1,3 butadiene, which may particularly affect children, and food pollution by food additives and by carcinogenic contaminants such as nitrates, pesticides, dioxins and other organochlorines. In addition, carcinogenic metals and metalloids, pharmaceutical medicines and cosmetics may be involved. Although the risk fraction attributable to environmental factors is still unknown, this long list of carcinogenic and especially mutagenic factors supports our working hypothesis according to which numerous cancers may in fact be caused by the recent modification of our environment.
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Long description: |
*In addition to ionizing irradiation (such as the exposure to radon or nuclear activities) non-ionizing irradiation including UV and pulsed electromagnetic
fields (EMF) can cause cancer, in particular, skin cancer (UV), some acute leukaemia and brain tumours in children (EMF).
*Regarding outdoor air pollution, long-term exposure in adults to particles and to polycyclic aromatic hydrocarbons (PAH), for example in the air of
polluted cities, can increase the risk of death due to lung cancer by 8% (without considering the effect of tobacco smoking). The risk is higher for the
more polluted cities and smoking can add to this risk. A recent European study estimated that the proportion of lung cancer attributable to traffic-
related air pollution and environmental tobacco smoke (ETS) in never- and ex-smokers was 5%-7% and 16%-24% respectively. In addition to PAH and
fine particles, NO2 might also be involved.
*The relevance of pesticides in carcinogenesis is steadily increasing. In children, several epidemiological studies revealed an increased relative risk of
cancer associated with parental exposure to occupational or non-occupational pesticides. Moreover, a positive association has been found by several
studies testing the direct exposure of children to pesticides. On the other hand, epidemiological studies in adults have provided conflicting results.
*For dioxins, although their carcinogenic mechanisms are not clear, a strong association between chronic exposure and an increased incidence of all
cancer types has been put forward.
*Chlorine is not itself carcinogenic but combined with organic matter in drinking water, it forms chlorination disinfection by-products (e.g.
trihalomethanes and haloacetic acids) that have been demonstrated to be mutagenic both in vitro and in vivo.
*Certain metals and metalloids have been rated as certain or probable carcinogens by the IARC. For example, lung cancer has been reported to be
associated with exposure to heavy metals, including lead, hexavalent chromium and nickel. Nevertheless, their mechanism of action is not yet well
understood.
Overall, this study provides evidence that supports the fact that, due to their mutagenic and/or promoting properties, many environmental factors,
including viruses, radiation and xenochemicals can contribute to causing a variety of cancers. The need remains to estimate the overall risk fraction
attributable to these environmental factors.
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Submitted By:
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Professor Paul Bardos WhoDoesWhat?
Last update: 13/10/2007
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