Today, cancer represented the second leading cause of death worldwide after cardiovascular disease. Over the past decades of cancer research, way of life – particularly physical inactivity, poor diet, obesity, alcoholism and smoking – and random or genetic factors have been identified as major causes in tumor development. However, we increasingly understand how environmental pollution is one of the main factors inducing the proliferation of cancers.
To explore this question further, a group of researchers from the University of Bologna, the University of Bari and the CNR (National Research Council) used advanced methods of artificial intelligence analyze the relationship between cancer mortality, socio-economic factors and sources of environmental pollution in Italy at regional and provincial level. The results and analysis of the survey have been published in the review Total Environmental Sciencewhile the ten-year dataset with cancer mortality rates for all Italian municipalities has been published in the journal Nature science dataan open access and user-friendly journal.
“Contrary to what was believed so far, our analysis showed that the distribution of cancer mortality among Italian citizens is neither random nor spatially well-defined,” explains Roberto Cazzola Gatti, professor in the Department of Biological, Geological and Environmental Sciences at the University of Bologna as well as first author of the study. “Instead, cancer mortality exceeds the national average, especially where environmental pollution is higheralthough in these areas lifestyles are generally healthier.”
The researchers took into consideration 35 environmental sources of pollution such as industries, pesticides, incinerators and automobile traffic. Of these, they found that air quality is the strongest factor in terms of association with the average cancer death rate. Then come the presence of sites to be reclaimed, urban areas, density of motorized vehicles and pesticides. Additionally, other specific sources of environmental pollution are relevant for specific tumor types. For example, cultivated areas are associated with tumors of the gastrointestinal system, proximity to roads and steel mills with bladder tumors, industrial activities in urban areas with prostate tumors and lymphomas.
The Italian province with the highest cancer mortality rate in the decade 2009-2018 was Lodi. It was followed by those of Naples, Bergamo, Pavia, Sondrio and Cremona. The highest ranked province in central Italy is Viterbo (11th position), followed by Rome (18th). In southern Italy, in addition to the province of Naples in second position, only that of Caserta (8th) is in the top 10 for cancer mortality. Everyone can check the ten-year mortality rate of their municipality by visiting the open access dataset published by the authors of the study.
“Of course, these results do not call into question the fact that a healthier lifestyle helps reduce the risk of cancerjust as they do not call into question efforts to arrive at the genetic basis that can promote the appearance of cancer,” adds Cazzola Gatti. “Our results, however, give us strong reason to believe that living in a heavily polluted area may negate the benefits of a healthy lifestyle and induce the development of cancers with a higher frequency.”
Every year in Italy there are 400,000 new cases of malignant tumors, with an annual average of about three deaths per thousand people according to Italian cancer registries. Both at the national and regional level, the analysis carried out by the researchers showed the importance of the environment on the appearance of tumors even when compared to other socio-economic and lifestyle factors. In addition, it was possible to determine at the provincial level which potential sources of pollution could cause an excess of cancer mortality compared to the national average, thus also emphasizing the environmental factors that are mainly associated with specific types of cancer.
“From a global health perspective, following the approach known as One Health, it is now evident that the quality of life of our species is closely dependent on that of the environment in which we live and of the entire planet”, explains Cazzola Gatti. “It is therefore necessary to give the highest priority not only to the search for cures for cancer, but also to the reduction and prevention of environmental contamination. These are essential actions in the difficult fight against the onset of cancer We need to know how to heal our planet so we can avoid getting sick.
According to the study, Italian regions with a relatively high cancer mortality rate have a relatively high degree of pollution, despite recording a relatively low frequency of the usual cancer risk factors such as overweight, smoking, low income, high meat consumption and low fruit and vegetable consumption. Moreover, at the provincial scale, for both malignant and benign tumors in general and for 16 of the 23 specific types of cancer, significant spatial associations were found with certain pollution sources and explained more than half of the association between the environment and cancer. This confirmed that, in most cases, exposure to a contaminated environment has a significant impact on cancer mortality in Italy.
“The data show good, albeit preliminary, evidence that better lifestyles and greater attention to socioeconomic and health issues can only partially reduce the risk of dying from cancer if the quality of the environment is neglected”, explains Cazzola Gatti. “This could explain why we have observed that people living in the northern regions of Italy – especially those located in the Po Valley, between the regions of Lombardy and Veneto, which are highly industrialized areas – and exposed to very high levels of environmental pollution show a large excess of cancer mortality compared to those living in the central-southern regions (except for some other highly polluted areas, such as the so-called Fuochi Land ( Land of Fires) in the Campania region), even though they enjoy better health, have higher incomes, consume more plant-based foods than animal-based foods, and have easier access to health care .
The entire decennial database (2009-2018) on cancer mortality rates developed by researchers from the ISTAT (Italian National Institute of Statistics) registers has been published in open access. In the database, 23 cancer macro categories in Italy at municipal, provincial and regional level are taken into account. “We want to make a complete, up-to-date and ready-to-use source of data on cancer mortality in Italy easily accessible for consultation by interested bodies and local and national authorities, and to provide researchers with useful data to carry out well-studied,” Cazzola Gatti concludes.
The study has been published in open access in the review Total Environmental Science under the title “The spatial association between environmental pollution and long-term cancer mortality in Italy”, while the dataset is in Nature science data. The authors of the study are Roberto Cazzola Gatti (University of Bologna), Arianna Di Paola (CNR – National Research Council, Institute of BioEconomics), Alfonso Monaco (University of Bari ‘Aldo Moro’), Alena Velishevskaya (Tomsk State University, Russia), Nicholas Amoroso (INFN – National Institute of Nuclear Physics, Bari Section), Roberto Bellotti (University of Bari ‘Aldo Moro’).
Total Environmental Science
The title of the article
The spatial association between environmental pollution and long-term cancer mortality in Italy