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

INTRODUCTION • Use of herbicides by US started in 1962 for defoliation and crop destruction in Vietnam. • Between 72 - 80 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

Herbicides in Da Nang Airbase RANCH HAND (May 1964 - 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. 1971 - Mar. 1972) • Collected and re-drumed 8,220 barrels Agent Orange • The herbicides were transported to Johnston Island, Central Pacific Ocean

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...”

Contaminated sites in Da Nang Airbase Other Areas of Concern

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

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

Dioxin Distribution in Soil Column in Da Nang Airbase 0 - 15 0 - 30 30 - 60 60 - 90 90-120 120-150 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

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

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

Herbicides in Bien Hoa Airbase RANCH HAND (Dec. 1966 - 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. 1970 - Mar. 1972) • Re-druming of 11,000 barrels Agent Orange and site cleanup occurred between Dec. 1971 - Mar. 1972

Spills of Herbicides in Bien Hoa • December 1969 - 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

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%)

CONTAMINATED SITES IN BIEN HOA AIRBASE

DISTRIBUTION OF DIOXIN RESIDUES (ppt TEQ) South runway Number of sample: 16 Range: 4.1 - 66,000 Site Z1 South-West runway Mean: 4,800 Median: 190 Number of sample: 19 Range: 40 - 5.1 x 106 Mean: 32,000 Number of sample: 15 Range: 80 - 23,000 Mean: 2,800 Z1-Perimetering land Number of sample: 31 Range: 6.2 - 1,300 Mean: 1,100 Median: 2,500 Median: 780 Median: 220 Z1- ponds/lakes Number of sample: 5 Range: 20 - 2,300 Mean: 960 Median: 750

Dioxin Distribution in Soil Column in Bien Hoa Airbase 0 - 20 20 - 30 30 - 40 40 - 60 60 - 90 90 - 120 120 - 150 5000 10000 15000 20000 25000 30000 At least 51,900 m3 of contaminated soil in Bien Hoa airbase need to be contained/ treated

Dioxin Contamination in Fish Bien Hoa Airbase

Dioxin Contamination in Serum of Selected Group Living in BH Airbase

Herbicides in Phu Cat Airbase RANCH HAND (Jun. 1968 - 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)

Contaminated sites in Phu Cat Airbase

Dioxin Contamination in Z3 & Nearby Areas

Dioxin Contamination in Pacer Ivy Site

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

Remediation of Contaminated Soil in Da Nang Airbase

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