1 THE NATIONAL DIOXIN AIR MONITORING NETWORK MEASUREMENTS OF CDDs, CDFs AND COPLANAR PCBs AT 18 RURAL, 8 NATIONAL PARKS, AND 2 SUBURBAN AREAS OF THE UNITED STATES: RESULTS FOR THE YEAR 2000 David H. Cleverly National Center for Environmental Assessment Office of Research and Development U. S. Environmental Protection Agency Washington, DC DIOXIN 2002: 22 st International Symposium on Halogenated Organics and POPs, Barcelona, Spain August 12– 16, 2002 The views presented in this paper are those of the authors and may not represent the the US Environmental Protection Agency

2 nNDAMN was established in 1998 to measure atmospheric levels of CDDs, CDFs and cp-PCBs in rural and agricultural areas, and to: n Establish background levels n Determine temporal and geographical variability n Investigate long-range transport and transboundary movement n Verify/calibrate air transport models Objectives of the National Dioxin Air Monitoring Network (NDAMN)

3 Measured Analytes

4 National Parks 4,19,23,24,25,26, 27,30

5 HI-VOL Dioxin PUF Sampler Magnehelic Gauge (0 – 100”) Sampling Head Venturi Voltage Variator Blower Motor 7-day Timer Exhaust Hose Aluminum Housing Airflow

6 Sampling Frame nSampling Period: l 24 hrs/d; 5 d/wk l 28 days n All stations operate simultaneously with 4 sampling periods/year

7 Detection Limits (fg/m 3 ) In order to meet these detection limits, it is necessary to sample 6000 – 8000 m 3 of air

8 Sampling Moments

9

10 2,3,7,8-TCDD

11 Rural DF TEQ: 14.6 fg/m3 Parks DF TEQ: 2.0 fg/m3 Rural PCB TEQ: 1.1 fg/m3 Parks PCB TEQ: 0.2 fg/m3

12

13

14 Conclusions §The mean TEQ DF –WHO 98 and PCB-TEQ air concentration measured at 18 rural areas is 14.6 fg m -3, and 1.1 fg m -3, recpectively. §The mean TEQ DF –WHO 98 and PCB-TEQ air concentration measured at 8 national parks is 2.0 fg m -3 and 0.2 fg m -3, respectively. §There was no change in CDD/CDF and PCB air concentrations from 1999.

15 Conclusions All 2,3,7,8-substituted CDD/CDF congeners were detected in ambient air at the 18 rural stations. l CDD/CDF compounds were detected in over 70% of the samples. l Excluding PCB 169, PCB compounds were detected in all samples. l In general, these results indicate that NDAMN sampling and analytical procedures are appropriate for generating sufficient data to assess background levels of CDD/CDFs and PCBs in rural areas of the united states.

16 Conclusions §The two suburban site (stations 13 and 31) had a mean TEQ DF –WHO 98 and PCB-TEQ of 15.5 fg m -3 and 2.0 fg m -, respectively. Thus the suburban sites had similar air concentrations of DF-TEQ as rural areas, but 10-fold higher mean PCB levels as compared to rural areas.

17 Conclusions §There was a 28-fold range in TEQ DF – WHO 98 annual average air concentrations at the rural sites: 60 to 2.5 fg m -3. §PCB-TEQ air concentrations ranged from 0.2 fg m -3 to 9.9 fg m -3, a range of approximately 50.

18 Conclusions §The lowest mean annual air concentration of dioxin-like compounds has consistently been observed at the Grand Canyon national park (site 24), with a mean of 0.3 fg m -3 DF- TEQ and 0.1 fg m -3 PCB-TEQ.

19 NDAMN Stations in 2000

20 Grand Canyon National Park, Arizona

21 Grand Canyon

22 Grand Canyon

23 Conclusions §The articulation of “background” concentrations of CDDs, CDFs and PCBs requires prolonged measurements taken annually over the course of several years. Furthermore, “background” should be associated with at least 3 distinct classifications of human habitation: rural, wilderness, and urban/suburban.

24 Acknowledgements YEPA: Dwain winters, Joe Ferrario, Chris Byrne, Aubrey Dupuy YBattelle: Karen Riggs, Pamela Hartford, Darrell Joseph, Tony Wisbith