Rising cases of cancer: Pollution blamed

As the sentinel of human health, the World Health Organization (WHO) rarely brings good news. Thursday 1 was no exception to that rule^er February: UN agency predicts an increase of about 35 million new cases of cancer by 2050. That’s a 77% increase compared to 2022, the agency, which specializes in the disease, said.

The study blamed air pollution as one of the main factors contributing to the rise in incidence.

Fine particles, then cellular bugs

“This is mainly about particulate pollution,” League Against Cancer spokesperson Dr. Emmanuel Ricard clarifies.

Diesel exhaust is one of the main sources of these particles, he continues: the best of them can travel down the lung tree, to the alveoli, these small “bags” where gases are exchanged between the lungs and the blood, oxygenating the latter. .

Our defense cells will “want” to remove these particles. Inflammation is as follows. This disturbs the cells which, instead of continuing to replicate in a healthy way, will begin to “bug”, becoming cancerous. “Regarding nothing, these cancer cells multiply and form a tumor,” popularizes the doctor.

More numerous, older, more sick

The study clearly shows that at least two factors in this increase in cases have nothing to do with pollution. Demographics, the first factor is just a simple arithmetic bias: as the number of humans continues to increase, so does the total number of cancer cases.

More numerous, our species is also aging. “But cancer is a problem of the immune system, and the older we get, the more the immune system declines. The result: the longer a population lives, the more susceptible it is to cancer.”

Another classic sham of any epidemiological data: best case diagnosis. Cases that already existed in the past, but escaped the medical radar, are now being discovered, causing the number to rise.

Worse, for epidemiologist Catherine Hill, we observe situations of “overdiagnosis”, where we strictly call the presence of cancer cells.

A textbook case in this area is prostate cancer: according to the Institute for Health Surveillance (INVS), 30% of 30-year-old men and 80% of 80-year-old men have cancer cells in their prostates. “It is extremely common: so it is clear that not all these cancer cells give rise to symptomatic cancer,” explains this expert in cancer frequency and causes.

Pollution and bad habits

More and more studies are establishing the link – often conditional – between pollution and the deterioration of our health, including mental health. Depressing: Pollution also increases depression.

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“A fashion”, full of scientific assumptions, annoys Catherine Hill. After tobacco, alcohol consumption is the main cause of cancer in France according to the WHO, recalls the epidemiologist. Citing a WHO International Cancer Research Center study, she asserted, “In France, pollution causes cancer 50 times less than tobacco and 20 times less than alcohol.

But it would be wrong to consider cancer factors separately, a spokesperson for the League Against Cancer cautioned. Faced with many factors, we are witnessing not a simple addition, but a multiplication of risk. The knowledge we have on the impact of the tobacco-alcohol combination has been demonstrated elsewhere, he continues: “We were able to find genes affected by cigarettes, like atmospheric pollution, in lung cancer” .

“The South”, this “dumping ground” of the world.

But this pollution factor is not the same for everyone, because we all do not breathe the same air. “In the big cities of China, India, South America, Tananarive (in Madagascar, editor’s note), or even Cairo, the pollution is so great that clouds of particles form. People get lung cancer under this ‘smog,’ like England during the Industrial Revolution,” Emmanuel Ricard notes.

Pollution is now being transferred to the “South”, which used to be the “dumping ground of the world”, continues Emmanuel Ricard: “In addition to the ‘dangerous’ factories that industrialized countries choose to relocate, we sell derivatives to developing economies. At low cost, But low quality oil tankers.

Those who have visited the megacities of these countries will agree: the pollution there seems more “sharp”. This is because it is actually more aggressive, explains Emmanuel Ricard: “Diesel produced in Europe is richer in sulfur and nitrogen”.

For that, the WHO report thus highlights the epidemic transition: countries that were mainly affected by infectious diseases – which have declined – will face the multiplication of diseases that were more common in Western countries, such as cancer.

Ecological click?

The latter, France, where air quality has improved over the past thirty years. In the Toulouse metropolitan area, for example, particulate matter and nitrogen oxides decreased by 40% and 17%, respectively, between 2009 and 2019. A positive effect on cardiovascular diseases, stroke, heart attack and cancer has been shown, notes Emmanuel Ricard.

Less encouraging: A study conducted in the Toulouse region also concludes that economically disadvantaged populations are more exposed to air pollution and are affected by deaths from long-term exposure.

Beyond these socio-economic inequalities, Xavier Briffault, researcher at the CNRS in the social sciences and philosophy of health, sees an ecological trigger: by showing a direct link between health and environmental degradation, science will lead us from moral ecology to public health. Ecology

Especially since health is not only the end of the ecological fight, but also a means, the researcher adds: by consolidating our fears, the issue of health allows us to put pressure on politicians according to the argument, “You not only protect the planet, but you killing us.”

“Pollution is bad” would thus become inappropriate: we would understand that pollution “does harm”.