1. ENVIRONMENTAL MONITORING OF DIOXIN LIKE COMPOUNDS IN THE UNITED STATES Commission for Environmental Cooperation of North America Fourth Workshop on Sources and Measurements of Dioxins, Furans and Hexachlorobenzene October 28-29, 2010 Dwain Winters Winters Environmental Bethesda, Maryland

2. CRITICAL AREAS FOR ENVIRONMENTAL MONITORING  DIOXIN IN LAKE SEDIMENT  DIOXIN IN AMBIANT AIR  DIOXIN IN SOIL

3. LAKE SEDIMENT CORE INVENTORY

4. TEMPORAL TRENDS IN SEDIMENT DIOXIN CONCENTRATION

5. NATIONAL DIOXIN AIR MONITORING NETWORK (NDAMN)  A nationally based ambient air monitoring network  The target analytes are vapor and particulate phases of dioxin-like compounds  32 stations operated in rural and non-impacted sites  Network started in 1999 and ended in 2004

6.  Establishing background levels  Determining temporal and geographical variability  Investigating long-range transport and transboundary movement  Verify/calibrating EPA’s air models  Providing data to determine exposures \ WHY WAS NDAMN CREATED?

7. Measured Analytes

8. Locations of NDAMN Stations = Rural Site = Remote Site

9. Dioxin Air Sampler Quartz Fiber Filter for particle bound dioxin PUF plug for vapor- phase dioxin

10. Sampling Frame Sampling period:  24 hrs/d; 7 d/wk  28 days All stations operate simultaneously with 4 sampling periods/year

11. NDAMN Sampling Moments

12. 2000 NDAM Annual Average

13. General increase observed in CDD/F TEQ in Late Fall/ Early Winter vs Summer Year Season Site (S) Summer (W) Winter

14. COMPARING 2001 RESULTS WITH POPULATION DENSITY NDAMN 2001 Population Density 2000

15. General Observations for NDAMN from 1999 - 2001 The dominant CDD/F congeners in ambient air were the OCDD>1,2,3,4,6,7,8-HpCDD> 1,2,3,4,6,7,8-HpCDF> OCDF.  This profile was constant over all NDAMN sites.  The 1,2,3,7,8-PCDD contributes over 40% of the dioxin TEQ.

16. General Observations for NDAMN from 1999 – 2001, continued  PCB-118 dominates coplanar PCBs in ambient air followed by PCB-105, PCB-77 and PCB-156.  PCB-126 dominates the TEQ.

17. NDAMN conclusions NDAMN conclusions 22 rural sites:  Annual mean dioxin TEQ (WHO method) air concentrations Range: 2 fg m 3 to 28 fg/ m 3 ; Overall mean: 12 fg m 3.  Mean annual PCB TEQ air concentrations Range: 0.15 – 9 fg/ m 3. Overall mean: 1 fg/ m 3.  These values are consistent with other studies of rural areas.

18. NDAMN CONCLUSIONS, continued 8 Remote Sites  Annual mean dioxin TEQ (WHO method) air concentrations Range: 0.5 to 3 fg/ m 3 Overall mean: 1.05 fg/ m 3  Mean annual PCB TEQ air concentrations Range: 0.05 – 1.0 fg/ m 3 Overall mean: 0.23 fg/ m 3

19. NDAMN CONCLUSIONS, continued  Dioxin concentrations at remote sites were on average one order of magnitude lower than what was measured at rural sites.  Although not statistically significant, PCBs were approximately 5-times lower in remote sites as compared to rural sites.

20. NDAMN CONCLUSIONS, continued NDAMN CONCLUSIONS, continued  CDDs and CDFs air concentrations have generally remained about the same from 1999 – 2001 when all NDAMN locations are considered.  CDD and CDF air concentrations have decreased from 1999 to 2001 at a few specific locations.

21. NATIONAL DIOXIN SOIL SURVEY NDAMN air sampling stations. Circles indicate stations included in soil survey and triangles are excluded stations.

22. Soil Survey Results

23. HRMS CDD/CDF TEQs for all 27 sites.

24. HRMS PCB TEQs for all 27 sites

25. AIR COMPARED TO SOIL