This study – known as Xenair and carried out by members of the Léon Bérard Center in Lyon, Gustave Roussy, the Ecole Centrale de Lyon, the University of Leicester (United Kingdom), INERIS, the Bordeaux Population Center Health – confirms, among other things, an increased risk of cancer be you when exposed to nitrogen dioxide. We already know very well the genetic or hormonal risk factors for breast cancer, the most common in women, and also those related to age or lifestyle (alcohol, physical activity, etc.).
Nitrogen dioxide involved
However, in recent years, several studies have also highlighted the role of certain pollutants. The authors of a meta-analysis published in 2021 pointed in particular to exposure to nitrogen dioxide, estimating that around 1,700 breast cancers each year in France might be linked to it. They considered, however, less conclusive the results on the risk associated with fine particles.
The authors of the Xenair study (funded by the ARC foundation) explored the association between the risk of breast cancer and chronic low-dose exposure to 8 air pollutants: pollutants with xenoestrogenic properties – dioxins , BaP, PCB, cadmium – and pollutants to which exposure is daily – fine particles (PM10 and PM2.5), nitrogen dioxide (NO2), ozone (O3) -, according to a press release.
Their work focused on 5,222 cases of breast cancer (diagnosed between 1990 and 2011), from a national cohort followed for 22 years, compared to the same number of unscathed cases. For each pollutant, average and cumulative exposures were estimated for each woman, taking particular account of places of residence.
An increase in the risk of breast cancer has, once more, been measured in connection with exposure to nitrogen dioxide. These results should give rise to a forthcoming publication in the journal Environmental Pollution. A risk has also been demonstrated with BaP and PCB153, two endocrine disruptors. The researchers also mention, this time, a risk linked to fine particles. But these results are not yet ready for publication. No association has been demonstrated for cadmium and dioxins, and analyzes are in progress for ozone.
If the exposure to pollutants of the women monitored has decreased since 1990, except for ozone, the exposure levels for nitrogen dioxide and particles remain far superior to health recommendations, observe the researchers. With exposure levels in line with the European thresholds for nitrogen dioxide (40 µg/m3), “1% of breast cancers in the XENAIR population might have been avoided” and, with levels in line with the recommendations of the WHO (10 µg/m3), the figure reaches “nearly 9%”, according to the press release.
With AFP.
