awmapres041905

Slide1: 

California Ambient Dioxin Air Monitoring Program (CADAMP) Kathy Gill Air Resources Board Monitoring and Laboratory Division California Environmental Protection Agency April 19, 2005

Background: 

Background Program initiated in 2000 - funding for two years of ambient monitoring Sampling began in December 2001 with 10 sites. Sampling conducted by BAAQMD, SCAQMD and ARB staff Monitoring for dioxins/furans, dioxin-like PCBs, and PBDEs (flame retardants) Data will be used to help understand dioxin levels in ambient air and prioritize risk management strategies

U.S. EPA Site Locations: 

U.S. EPA Site Locations U.S. EPA established a national dioxin air monitoring network (NDAMN) to estimate rural ambient air concentrations of dioxins/furans and PCBs throughout the U.S. Operated from 1998 through 2002 with up to 30 sites. CADAMP design similar to NDAMN (1/28 days vs. 1/3 months) NDAMN sites in California located in: - Bay Area (Fort Cronkhite, San Francisco) - Central Valley (Rancho Seco Park)

Sampling : 

Sampling Based on U.S. EPA Method TO-9A PS-1 type high volume sampler normally used for 24-hour samples Each sample 1 PUF/XAD/PUF sandwich in glass cartridge 4 Quartz Fiber Filters (QFF) CADAMP extended sampling periods of 28 days Four sub-periods (5-6 days on, 1-2 days off) QFF changed each week to prevent overloading and maintain flow rate PUF/XAD/PUF remains in place for all 28 days

Slide6: 

Sampling Head Chart Recorder Timer and Flow Controller Magnehelic Gauge

Benefits of Long Duration/Large Volume Sampling: 

Benefits of Long Duration/Large Volume Sampling Collecting 6000 - 8000 L of air Provides low detection limits (~0.2 fg/m3 for 2,3,7,8-TCDD) Minimizes the non-detects Provides comprehensive temporal coverage (representativeness) Minimizes number of samples collected Reduces lab costs

Analysis: 

Analysis U.S. EPA Established Procedures Method TO-9A/1613A for 17 dioxins/furans Method 1668A for 14 PCBs Draft Method 1614 for 44 PBDEs Single sample; extract split 3 ways Dioxin/Furans PCBs and PBDEs Archive portion

Valid Results: 

Valid Results Extensive field and laboratory validation criteria applied to data 2002 101 valid samples (84% completeness) 21 valid field blanks (88% completeness) 2003 145 valid samples (93% completeness) 25 valid field blanks (96% completeness)

Toxicity Equivalence Factors (TEFs): 

Toxicity Equivalence Factors (TEFs) Concentrations for dioxins expressed as toxicity equivalence (TEQ) TEFs are numerical factors that express toxicity of each dioxin, furan or PCB relative to the toxicity of 2,3,7,8-TCDD 1997 WHO TEFs Adopted by California in 2003 - replaced the I-TEFs Used in NDAMN, making data comparisons between the two networks possible

Concentration Results: 

Concentration Results Lab results reported as picograms/sample (pg = 10-12) Calculate air concentration femtograms/cubic meter (fg = 10-15) Convert to Toxicity Equivalence fg TEQ/cubic meter

2002/2003 QC: 

2002/2003 QC Collocated Samples Average Field Blank Concentrations 0.48 fg TEQ/m3 for D/F 0.04 fg TEQ/m3 for PCBs

San Francisco Bay Area Sampling Period TEQ Averages 2002 2003: 

San Francisco Bay Area Sampling Period TEQ Averages 2002 2003 Includes all valid samples for each sampling period

South Coast Area Sampling Period TEQ Averages 2002 2003: 

South Coast Area Sampling Period TEQ Averages 2002 2003 Includes all valid samples for each sampling period

CADAMP Averages: 

CADAMP Averages PCB contribution to Total TEQ was up to 50%

Comparison of CADAMP Results: 

Comparison of CADAMP Results Key Factors to Consider in Comparing Data to Other Studies TEFs (which scheme used?) Detection limits (DL) factored as DL, 1/2 DL or zero for TEQ calculation if elevated (due to volume collected or analytical technique) can impact TEQ Blank corrections Short vs. long duration sampling CADAMP annual averages vs. few data points Remote - rural - urban - source impacted?

2004/2005 Monitoring: 

2004/2005 Monitoring 2004 continued as 2003 with 10 sites and 2 collocated samplers 2005 - Retained one Bay Area site (Livermore) and one South Coast site (Rubidoux) Installed sampler in San Joaquin Valley at Fresno in January 2005 Will add rural San Joaquin Valley site to conduct high population urban vs. rural comparison and obtain rural PBDE data Continue for 13 sampling moments

ARB Web Pageswww.arb.ca.gov/aaqm/qmosopas/dioxins/dioxins.htm: 

ARB Web Pages www.arb.ca.gov/aaqm/qmosopas/dioxins/dioxins.htm Web pages contain: Maps and site histories QAPP, FOP, methods, sampling schedules Individual congener concentrations and TEQ for both D/F and PCB at each site Quarterly and annual averages for each site Regional and statewide averages Downloadable data - Excel format 2003 PBDE and all 2004 data expected to be released and on web in near future

ARB Dioxin Web Site: 

ARB Dioxin Web Site www.arb.ca.gov/aaqm/qmosopas/dioxins/dioxins.htm