Size and composition distribution of airborne particulate matter in northern California: I--particulate mass, carbon, and water-soluble ions.
J Air Waste Manag Assoc
; 55(1): 30-51, 2005 Jan.
Article
en En
| MEDLINE
| ID: mdl-15704538
ABSTRACT
The San Joaquin Valley (SJV) in California has one of the most severe particulate air quality problems in the United States during the winter season. In the current study, measurements of particulate matter (PM) smaller than 10 microm in aerodynamic diameter (PM10), fine particles (PM18), and ultrafine particles (PM0.1) made during the period December 16, 2000-February 3, 2001, at six locations near or within the SJV are discussed Bodega Bay, Davis, Sacramento, Modesto, Bakersfield, and Sequoia National Park. Airborne PM1.8 concentrations at the most heavily polluted site (Bakersfield) increased from 20 to 172 microg/m3 during the period December 16, 2000-January 7, 2001. The majority of the fine particle mass was ammonium nitrate driven by an excess of gas-phase ammonia. Peak PM0.1 concentrations (8-12 hr average) were approximately 2.4 microg/m3 measured at night in Sacramento and Bakersfield. Ultrafine particle concentrations were distinctly diurnal, with daytime concentrations approximately 50% lower than nighttime concentrations. PMO.1 concentrations did not accumulate during the multiweek stagnation period; rather, PMO.1 mass decreased at Bakersfield as PM1.8 mass was increasing. The majority of the ultrafine particle mass was associated with carbonaceous material. The high concentrations of ultrafine particles in the SJV pose a potential serious public health threat that should be addressed.
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Bases de datos:
MEDLINE
Asunto principal:
Contaminantes Atmosféricos
/
Nitratos
Tipo de estudio:
Etiology_studies
/
Risk_factors_studies
Límite:
Humans
País/Región como asunto:
America do norte
Idioma:
En
Revista:
J Air Waste Manag Assoc
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2005
Tipo del documento:
Article
País de afiliación:
Estados Unidos