1995 integrated monitoring study: temporal variability of particulate matter-preliminary results

摘要

During the winter portion of the 1995 Integrated Monitoring Study (IMS95), 3-hour PM_(10) and PM_(2.5) sampling was conducted at four sites in the central and southern San Joaquin Valley. The objectives of the monitoring were to assess the diurnal variations in particulate matter (PM) concentrations and to provide information on the optimal averaging times to be used in future monitoring in the Valley. Data on PM_(10) and PM_(2.5) mass and composition (ions, OC/EC, and elements) were collected at Bakersfield, Fresno, Kern Wildife Refuge, and Chowchilla from Decmber 9, 1995 through January 6, 1996. Prelimiary analysis of the mass data show that highest concentrations were observed at Fresno, with a maximum 24-hour PM_(10) concentration of 125 ug/m3 and a maximum 24-hour PM_(2.5) concentration of 104 ug/m3. In general, PM_(2.5) comprised 70