Photothermal Deflection Spectroscopy of Collected Aerosols

Logan, Utah USA Elevation 4535 feet (1382 m) Population 42,670 (91,391 total valley) 80 miles from nearest population center- Salt Lake City ~ 250,000 popIndustry: AgricultureUp-wind: deserts- no industryAir Quality: Worst PM 2.5 in USA !– (Winter 2004/2005)Reason: Cars + Cows (NH 3 + HNO 3 → NH 4 NO 3 )– Some carbonaceous and sulfate aerosolsCurrent Analysis– Particle counting (laser scattering)– Particle collection and analysisUSA Today Posted 3/8/2005 4:04 PM“Northern Utah residents choke on bad air LOGAN, Utah (AP) — In thesummer, Cache Valley's verdant parks and riverside trails in theWasatch Range are a haven for outdoor enthusiasts who describe thisnorthern Utah mountain basin as a kind of Shangri-La.For about 40 days since November, at-risk residents like Koerner, 54— who make up 30% of the valley's population — have choked on anunrelenting pea soup of smoky haze, much of it belched by the enginesof the area's estimated 75,000 automobiles. …”