Sources of indoor PM2.5 gross α and β activities measured in 340 homes

Particle radioactivity (PR) exposure has been linked to adverse health effects. PR refers to the presence of α- and β-emitting radioisotopes attached to fine particulate matter (PM2.5). This study investigated sources contributing to indoor PM2.5 gross α- and β-radioactivity levels. We measured activity from long-lived radon progeny radionuclides from archived PM2.5 samples collected in 340 homes in Massachusetts during the period 2006–2010. We analyzed the data using linear mixed effects models and positive matrix factorization (PMF) analysis. Indoor PM2.5 gross α-activity levels were correlated with sulfur (S), iron (Fe), bromine (Br), vanadium (V), sodium (Na), lead (Pb), potassium (K), calcium (Ca), silicon (Si), zinc (Zn), arsenic (As), titanium (Ti), radon (222Rn) and black carbon (BC) concentrations (p