Lung cancer cases attributable to PM2.5 in northeastern Italy

BACKGROUND: According to the International Agency for Cancer Research (IARC), outdoor pollution is a well established cause of lung cancer, with a prominent carcinogenic role attributed to particulate matter (PM) pollution. 2001 WHO guidelines on outdoor pollution includes a recommendation to reach a PM2.5 annual average of 5ug/m(3). The WHO recommendation is in sharp contrast with EU limits: thus, in the present study we estimated the number of incident lung cancer cases due to PM2.5 according to three different scenarios. METHODS: The number of newly incident lung cancer cases diagnosed in northeastern Italy from 2015 to 2020 was from the population-based cancer registry of the Friuli Venezia Giulia region. We considered three scenarios of average annual concentration of PM2.5: 25ug/m(3) according to EU legislation; 10ug/m(3) or 5ug/m(3) according to 2005 and 2021 WHO guidelines. An 8% increase in the risk of lung cancer for every 10ug/m(3) increase in PM2.5 was assumed. Data from outdoor average annual concentration of PM2.5 in northeastern Italy were from local air monitoring systems. RESULTS: 5131 lung cancer cases were registered in 2015-2020 in Friuli Venezia Giulia, (i.e., 855 cases/year). In the same period, an average annual concentration of PM2.5 of 18ug/m(3) was documented. According to EU legislation, there will not be an excess of future lung cancer cases attributable to PM2.5. Conversely, the projection of the excess cases ranged from 6.4%/year (WHO 2005) or 10.4% (WHO 2021). In absolute terms, we estimated that there will be an excess of future yearly lung cancer cases ranging from 55 cases to 89 cases due to PM2.5.air pollution exceeding WHO recommendations. CONCLUSIONS: According to WHO recommendations, PM2.5 air pollution will cause an excess of up to 89 yearly cases of lung cancer in Friuli Venezia Giulia, northeastern Italy, a projection in sharp contrast with EU limits. KEY MESSAGES: • An excess of up to 89 yearly cases of lung cancer are projected for the future years due to PM2.5 concentration exceeding WHO guidelines. • EU limits of PM2.5 average yearly concentration underestimate the risk of lung cancer in humans.