Ambient PM_(2.5) Sources, Composition, and Contributions to Personal Exposure in Southern Delaware

摘要

Sampling conducted for PM2.5 during the fall of 2011 and 2012 indicated the geometric mean ambient PM_(2.5) concentrations of the Millsboro area was 9.3 μg/m~3. The semi-rural location of Seaford had an average PM_(2.5) concentration of 8.9 μg/m~3, both below the Federal Standard of 15 μg/m~3 and were not statistically different at a test value of α=0.01. Sampling conducted outdoors and indoors of 35 distinct participants (32 each season) resulted in average PM_(2.5) concentrations of 11.3 μg/m~3 and 11.8 μg/m~3 respectively. The higher elevated indoor concentration is expected due to the strength and proximity of PM_(2.5) sources found indoors (e.g. cooking, cleaning, candle burning, smoking, etc.). Personal level sampling conducted during both seasons revealed geometric mean PM_(2.5) concentrations of 20.3 μg/m~3 across both seasons. Similar to indoor PM_(2.5) measurements that were elevated with respect outdoor and ambient measurement, higher personal level concentrations were presumably due to personal proximity and strength of sources and is to be expected based on previous studies.