Elemental analysis of infant airborne particulate exposures.

Air pollution is hypothesized to have negative impacts on infant pulmonary health because of infants' increased rates of respiration and ongoing lung development. The severity and type of impact may differ depending on elemental concentrations. We conducted a study of 21 infants <6 months old whose parents carried a small personal particulate monitoring device (RTI MicroPEM) and GPS unit with the infant for 7 days in January and February 2015. The study area was Utah County, UT, USA. Real-time particulate exposure levels, as well as optical density and elemental analysis of the particulate matter (PM), were compared with levels from an outdoor stationary monitor. Infants spent an average of 87.4% of their time indoors. PM levels varied widely by infant and time of day (average=19.07 μg/m3, range=0.63-170.25 μg/m3). Infant particulate exposures were not well approximated by the outdoor monitor. Infants had lower exposures to Sb, Mn, Pb, W and Fe than the outdoor monitor and higher exposures to Cd, Ni and Na. Differences were most pronounced for Na. Brown carbon was only detected by personal monitors and not by the outdoor monitor. Further research is needed to understand the potential implications of indoor elemental exposures on early respiratory development.