The average concentration of particulate matter (PM) in the air breathed by a person in Palo Alto is 25 μg/m3. Assume that 75% of PM (by mass) is 6 μm particles, 20% is 2 μm particles, and 5% is 0.1 μm particles.
The book "Exposure Analysis" (533p), edited by Wayne R. Ott, Anne C. Steinemann, and Lance A. Wallace, was published in 2007 by CRC Press, Boca Raton (Taylor & Francis Group). It is the first complete resource in the emerging scientific discipline of exposure analysis.