1. AO/Dioxin in Three Former US Airbases (South Vietnam): Environmental Level, Human Exposure and Stages of Remediation
Nguyen Hung Minh
Dioxin Laboratory Project, Vietnam Environment Administration
556 Nguyen Van Cu Street, Long Bien, Ha Noi

2. INTRODUCTION
• Use of herbicides by US started in 1962 for defoliation and crop destruction in Vietnam.
• Between millions litter of herbicides contaminated by Dioxin were used in South Vietnam in Ranch Hand Operation
• The application was ceased in 1971 and
Pacer Ivy Operation was followed to revoke
and re-drum unused herbicide barrels and transported back to US

3. Herbicides in Da Nang Airbase
RANCH HAND (May Jan. 1971)
Total transport and handling amount:
• Agent Orange: 52,700 barrels (10,961,600 L)
• Agent White: 29,000 barrels (6,032,000 L)
• Agent Green: 5,000 barrels (1,040,000 L)
PACER IVY (Dec Mar. 1972)
• Collected and re-drumed 8,220 barrels Agent Orange
• The herbicides were transported to Johnston Island, Central Pacific Ocean

4. Leakages of Herbicides in Da Nang
Report 1: Chief, CORDS/ New life development (March 27, 1969)
“...the method used by ARVN personnel to transfer the herbicide from drums to larger tanks results in two to three gallon residue being left in each. These drums are then allegedly sold to local citizens for300
piasters each...”
Report 2: Defoliant Damage in Da Nang” - Col. Harold C. Kinne. March 29, 1969”
“... primary cause of damage was not from aircraft, but rather, the spread of small amounts of herbicide throughout the area by means of empty herbicide drums...”

5. Contaminated sites in Da Nang Airbase
Other Areas
of Concern

6. RESULT: CONTAMINATION IN DA NANG
< 6 ppt TEQ
6 - 10,000 ppt TEQ
1, ,000 ppt TEQ
10, ,000 ppt TEQ
> 150,000 ppt TEQ

7. Comparison for soils inside & outside of Da Nang Airbase
TCDD and TEQ in the airbase soil
TCDD and TEQ in soil & sediment
far from the airbase
TCDD
TEQ
TCDD
TEQ

8. Dioxin Distribution in Soil Column in Da Nang Airbase
0 - 15
0 - 30
90-120
2000
4000
6000
8000
10000
12000
Concentration ppt TEQ
1,000 ppt TEQ as guideline
• Vertical migration of dioxin to deeper soil layers probably caused by movement of diesel used as solvent for herbicides
• About 47,500 m3 of contaminated soil (excluded sediment) need to be contained/treated

9. Da Nang airbase – dioxin concentrations in fish
Survey in 2006 & 2009
10000
Max. allowable level:
1000
US FDA, Health Canada, EU
100
50 pg/g TEQs wet wt
20 pg/g TEQs wet wt 10
4 pg/g TEQs wet wt 1
0.1
0.01

10. Da Nang airbase – dioxin concentrations in human blood in some areas 2006

11. Herbicides in Bien Hoa Airbase
RANCH HAND (Dec Feb. 1970)
Total transport and handling amount:
• Agent Orange: 98,000 barrels (20,384,000 L)
• Agent White: 45,000 barrels (9,360,000 L)
• Agent Blue: 16,300 barrels (3,390,000 L)
PACER IVY (Apr Mar. 1972)
• Re-druming of 11,000 barrels Agent Orange and site cleanup occurred between Dec Mar. 1972

12. Spills of Herbicides in Bien Hoa
• December March 1970: Four spills from
28,000-liter tanks occured.
- Two spills of Agent White: 2,500 L
- Two spills of Agent Orange: 25,000 L

13. Bien Hoa City and The Airbase
Bien Hoa Airbase
• Bien Hoa City belongs to Dong Nai provinces, 35 km north west of Ho Chi Minh City
• Population: 548,860 (Bien Hoa city only)
• Economy Composition: Industry & construction (70.1%); Agriculture & Forestry (28.72%); Services (1.18%)

14. CONTAMINATED SITES IN BIEN HOA AIRBASE

15. DISTRIBUTION OF DIOXIN RESIDUES (ppt TEQ)
South runway
Number of sample: 16
Range: ,000
Site Z1
South-West runway
Mean: 4,800 Median: 190
Number of sample: 19 Range: x 106 Mean: 32,000
Number of sample: 15
Range: ,000 Mean: 2,800
Z1-Perimetering land
Number of sample: 31 Range: ,300 Mean: 1,100
Median: 2,500
Median: 780
Median: 220
Z1- ponds/lakes
Number of sample: 5 Range: ,300 Mean: 960
Median: 750

16. Dioxin Distribution in Soil Column in Bien Hoa Airbase
0 - 20
5000
10000
15000
20000
25000
30000
At least 51,900 m3 of contaminated soil in Bien Hoa airbase need to be contained/ treated

17. Dioxin Contamination in Fish
Bien Hoa Airbase

18. Dioxin Contamination in Serum of Selected Group Living in BH Airbase

19. Herbicides in Phu Cat Airbase
RANCH HAND (Jun May. 1970)
Total transport and handling amount:
• Agent Orange: 17,000 barrels (3,536,000 L)
• Agent White: 9,000 barrels (1,872,000 L)
• Agent Blue: 2,900 barrels (603,200 L)

20. Contaminated sites in Phu Cat Airbase

21. Dioxin Contamination in Z3 & Nearby Areas

22. Dioxin Contamination in Pacer Ivy Site

23. Stages of Remediation Hot spots in Bien Hoa airbase
• Z1 area was contained in secured landfill
• Remaining areas are being under consideration (Testing
for bioremediation and ball milling technologies)
Hot spots in Phu Cat Airbase
• The contaminated soil will be contained in secured
landfill (similar to Z1 site in Bien Hoa)
Hot spots in Da Nang Airbase
• The contaminated soil will be treated by in-situ thermal
desorption to remove dioxin from soil and trap in carbon

24. Remediation of Contaminated Soil in
Da Nang Airbase

25. Remediation of Contaminated Soil in
Da Nang Airbase
Steel Sheeting
60 m
Insulation Panel
Insulated Cap
6.0 m
Excavated Soil
Clean Soil
Heater-Only Well Existing Grade
Drain Gravel
Heater-Vacuum Well Air Inlet Well
Piped to Layer
Sump Insulated Floor
Not to scale - Only a Subset of Wells are Indicated