[The radon risk in Lombardy]

Area of Science:

• Environmental Health
• Epidemiology
• Geology

Background:

• Lung cancer mortality rates exhibit significant geographical and gender disparities in Italy.
• Previous studies suggest a correlation between male lung cancer rates and cigarette smoking.
• Elevated lung cancer incidence in specific northern Italian regions necessitates investigation into environmental risk factors.

Purpose of the Study:

• To investigate the geographical distribution of lung cancer mortality in Italy, focusing on Lombardy and Emilia-Romagna.
• To assess the potential risk of indoor radon exposure as a contributing factor to lung cancer mortality.
• To correlate radon levels with regional geological characteristics and lung cancer rates.

Main Methods:

• Utilized death certificate data from the Central Institute of Statistics (ISTAT) for 1980-1988 to calculate mortality rates.
• Analyzed geographical variations in lung cancer mortality, comparing northern and southern regions, and male versus female populations.
• Assessed indoor radon exposure levels in dwellings and correlated them with regional geology (granite in Lombardy, calcareous in Emilia-Romagna) and lung cancer excess events using a National Academy of Sciences model.

Main Results:

• Lung cancer mortality rates were higher in northern Italy and significantly higher in males (>10x).
• Male mortality rates showed a linear correlation with past cigarette smoking.
• Lombardy, with radon levels around 100 Bq/m3 originating from granite-rich Alps, exhibited lung cancer mortality rates over 50% higher than estimated, aligning with radon risk models.
• Emilia-Romagna, with lower radon levels (around 50 Bq/m3) from low-uranium calcareous rocks, showed a less significant radon risk factor.

Conclusions:

• Indoor radon exposure, particularly in Lombardy, is a significant contributing factor to elevated lung cancer mortality rates, especially in males.
• Geological factors influencing radon concentration in dwellings play a crucial role in regional lung cancer risk.
• The study highlights the importance of considering indoor radon as an environmental carcinogen in public health strategies for lung cancer prevention.