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Slide 1

A Mass Budget of Polybrominated Diphenyl Ethers in San Francisco

Bay, CA

John J. Oram, Lester J. McKee, Christine E. Werme, Mike S. Connor,

and Daniel R. Oros

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Slide 2

Introduction• Flame retardants in plastics and textiles• Ubiquitous environmental pollutants• Only recently included in environmental assessments• Appear to be exponentially increasing throughout the

world• Transport pathways not fully understood

– Thought to be similar to PCBS, OC Pesticides.

• This paper is first of its kind for– PBDEs in urban rivers– PBDE mass budget for urbanized estuary

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Slide 3

Source: Kim Hooper et al. Cal EPA

SF Bay is Global Hot SpotPBDE-47 in Human Tissues

0

5

10

15

20

25

30

35

1981 1983 1985 1987 1990 1992 1994 1996 1998 2000

PB

DE

-47,

ng/

g li

pid

s

U.S. (San Francisco, adipose)Sweden (adipose)Germany (whole blood)Canada (milk)Finland (milk)Japan (milk)Sweden (milk)

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Slide 4

Pieces of the Mass Budget

• Bay water and sediment– Inventory

• Unfiltered water at Mallard Island, Coyote Creek, Guadalupe River, and Zone 4 Line A– Tributary loads

• Effluent and sludge from 3 tertiary plants– Wastewater loads

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Slide 5

Bay Inventory

Mean Lower 95% CI Upper 95% CIBDE 047 31.44 28.89 33.99BDE 209 97.98 54.61 141.37

Total Mass in Water and Sediment (kg)

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Mallard IslandB

DE

-47

(ng/

L)

SSC (mg/L)

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Guadalupe River

WY 2005

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Comparison of Tributaries

Min Max FWMC Min Max FWMC Min Max FWMCBDE 047 1.69 26.50 7.99 1.25 3.53 2.63 0.17 0.22 0.18BDE 209 8.50 115.00 43.30 7.29 22.40 14.66 0.12 0.26 0.15BDE 047 0.56 18.40 5.29 0.13 0.35 0.14BDE 209 1.74 119.00 32.32

WY 2006

Guadalupe Coyote MallardCongener

WY 2005

BDE 047 : BDE 209Guadalupe = 0.2Coyote = 0.2Mallard = 1.2

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Slide 9

• Why more BDE 047 @ Mallard?– Two hypothesis are emerging:

1. Atmospheric deposition to Central Valley• 47 more volatile than 209 = greater potential for

long-range atmospheric transport & deposition

2. Dissolved loads greater• 47 more soluble than 209; Combined with long

residence time of Delta (weeks to months) may make dissolved loads more important

BDE 047 : BDE 209Guadalupe = 0.2Coyote = 0.2Mallard = 1.2

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Slide 10

Location PBDEs - BDE 209 BDE 047 BDE 209

Canada (Columbia River)1 3.8 - 90.9

China (Pearl River Delta)2 0.04 - 94.7 0.4 - 7340

China (Yangtze River Delta)8 ND - 0.55 0.16 - 94.6

China3 0.1 - 5.5

Denmark3 0.53 3.67 - 21.5

Japan3 8 - 352 <25 - 11600

Korea3 1.1 - 33.8

Kuwait7 0.08 - 3.8

Netherlands3 0.6 - 17.6 4 - 510

Portugal 0.5 - 203 0.03 - 9.9112

Spain 0.4 - 34.13 0.1 - 0.29 2.1 - 1323

Sweden 8 - 503 <1.611 68 - 71003

UK 1.3 - 1270.83 <0.3 - 36810 0.6 - 31903

USA <0.5 - 63.63,4 <0.5 - 52.313 29 - 15483,5

This Study

Coyote Creek, CA6 19.3 - 128.8 4.6 - 31.9 17.1 - 202.9

Guadalupe River, CA6 29.1 - 1248.4 7.4 - 219.9 23.3 - 1997.6

Mallard Island, CA6 5.5 - 9.6 2.4 - 3.7 2.2 - 6.5

SF Bay, CA ND - 21214 0.05 - 3.84 0.1 - 12.6

PBDE concentrations (ng/g) in San Francisco river and bay sediments compared to world river and coastal sediments.

* Normalized to SSC

***

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Slide 11

Summary of Loads

Source PBDEs BDE 047 BDE 209Sacramento-San Joaquin Delta 13 3 3Local Tributaries 33 3 17Municipal Wastwater 12 - 58 4 - 21 1 - 3Atmospheric Deposition 1 - 2 ~1 ~1Total 59 - 106 11 - 28 22 - 24

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Mass Budget ModelHindcast – Estimation/Verification of Loads

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Mass Budget ModelForecast – Plausible Future Trajectories

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Mass Budget ModelLoss Pathways Under Zero Loads Scenario

Outflow and Degradation Are Most Important Loss Pathways

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Conclusions

• SF Bay is global hot spot

• Loads dominated by local tributaries (stormwater runoff) and wastewater

• Model provides useful framework for integrating / synthesizing information

• SF Bay at critical juncture in terms of recovery