Levels of Polonium-210 in brain and pulmonary tissues: Preliminary study in autopsies conducted in the city of Sao Paulo, Brazil.

The accumulation of detectable amounts of radon progeny in human tissues may be a risk factor for development and progression of chronic diseases. In this preliminary study, we analyzed the levels of alpha-emitting radon progeny Polonium-210 (210Po) in the olfactory epithelium, olfactory bulb, frontal lobe, and lung tissues in cadavers from the city of Sao Paulo, SP, Brazil. We also assessed the association between 210Po levels and exposure parameters for urban air pollution using linear regression models adjusted for age, sex, smoke, time living in Sao Paulo, daily commuting, socioeconomic index, and anthracosis (traffic-related black carbon accumulation in the pleural region and in lymph). Our findings show that the concentration of 210Po was associated with anthracosis in lungs of non-smokers (coefficient = 6.0; standard error = 2.9; p = 0.04). Individuals with lower socioeconomic status also had significantly higher 210Po levels in lungs (coefficient = -1.19; standard error = 0.58; p = 0.042). The olfactory bulb had higher 210Po levels than either olfactory epithelium (p = 0.071), frontal lobe (p < 0.001), or lungs (p = 0.037). Our findings of the deposition of 210Po in autopsy tissues suggest that airborne radionuclides may contribute to the development of chronic diseases, including neurodegenerative diseases.