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

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

LAKE SEDIMENT CORE INVENTORY

TEMPORAL TRENDS IN SEDIMENT DIOXIN CONCENTRATION

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

 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?

Measured Analytes

Locations of NDAMN Stations = Rural Site = Remote Site

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

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

NDAMN Sampling Moments

2000 NDAM Annual Average

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

COMPARING 2001 RESULTS WITH POPULATION DENSITY NDAMN 2001 Population Density 2000

General Observations for NDAMN from 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.

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.

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.

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

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.

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.

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

Soil Survey Results

HRMS CDD/CDF TEQs for all 27 sites.

HRMS PCB TEQs for all 27 sites

AIR COMPARED TO SOIL