ASSESSMENT OF AGENT ORANGE- DIOXIN IN SOIL AND ON THE AQUATIC PRODUCTS IN HO CHI MINH CITY Departement of Research and development Center of Analytical service and experimentation (CASE) HoChiMinh city, Vietnam
INTRODUCTION
Between 1962 and 1971, Seventy two million litres of herbicides named Agent orange dioxin were sprayed on more than 3.6 million hectares of forest and villages in central and southern Vietnam with the aim of killing all the vegetation [1 ].
Dioxin is described as the most toxic subtance discovered by mankind up to this time. It is very persistence in human tissues and the environment
Research on American ex-servicemen from the vietnam war has shown significant associations between dioxin exposure and certain kinds of cancer.the effect of herbicides on the health of the Vietnamese population, the U.S.National Academy of sciences (NAS) report was quite specific.
Interviews with the montagnard people, conducted by Dr. Gerald Hickey of Cornell University, provided remarkably consistent reports of the range of effects on children following spray missions; diarrhea, skin rashes resembling insect bites, abdominal pain, and death [2 ]. Dr. Le cao Dai-Vietnam Red Crossdemontrated that over five percent of children of Vietnamese ex-soldiers exposed to agent orange were born with defects, compared to only one percent among soldiers who remained in the north Vietnam and avoided exposure [ 3].
Up to now, there are four researchs about dioxin residues in the environment and in the food at the areas most heavily sprayed with Agent Orange of Ho Chi Minh city during the Chemical war in Vietnam:
The first, in 1973, just after stopping spraying programs, M. Meselson and R.Baughman analysed the TCDD level in the samples of fish, shrimp of the Dong Nai river, Saigon river and on the CanGio coast [ 4]. The second, in 1986-1987, analysed the TCDD level in the soil samples of cangio district, conducted by group of Prof. Nguyen duc Hue [5 ].
The third, in 1989-1991, determination the TCDD level in the 111 soil samples ( Ho Chi Minh city: 9 samples), realised by group of Prof M.Matsuda and Prof Hoang dinh Cau [6 ]. The fourth, in 1988-1993, K.Olie and Committee 10-80, Vietnam analysed the PCDDs/PCDFs in some aquatic samples such as sheat fish, shrimp, crab, eal [ 7].
All analytical results of TCDD levels were carried out by the foreign laboratories ( in Japan, Holland, Germany, USA)
In 2002, following a projet research, supported by Department of Scienc e and technology Ho Chi Minh city [8 ]; CASE collected 29 samples: soil, food and aquatic product. The aim of our reseach was to identify the dioxin residues in the areas most heavily sprayed with agent orange of Ho chi minh city, after 30 years the defoliant operation was halted by the US military. We present our results in comparison with those of others authors before
INSTRUMENTAL ANALYSIS
All analyses were performed on HRGC- HRMS system: Chromatographic separations were achieved using Hewlett-Packard 5890 Series II high resolution gas chromatograph, utilising a 60m-0,35mm-0,25µm film thickness- DB5 capillary column. The HRMS was operated in the electron impact ionization mode using selected ion monitoring (SIM). The mass spectrometer was tuned and calibrated prior to all analysis. It was tuned to a resolution of 10,000ppm using m/z 330.9792
ANALYTICAL RESULTS
A. ON SOILS SAMPLES
Year Sample location Sample depth (cm) Concentration 2,3,7,8 TCDD (ppt) Author Laboratory of analysis 1986 1987 Tam thon Hiep (CanGio) Rung Sat (Can Gio) 0-5 20 30 60 0-5 0-5 30,5 45,0 5,4 Not detected 22,7 6,0 Ng-ñ-Hueä Japan and Holland 1989-1991 Hanoi city Hue province Binh Phuoc province TayNinh province Ho Chi Minh city 0-10 0-10 0-10 0-10 0-10 Not detected 8,6 6,0 14,0 31,0 M.Matsuda & Hoang dinh Cau Japan 2002 in HoChi Minh city Ly Nhon, CanGio ThanhAn,CanGio TanNhat,BinhChanh BinhLoi,BinhChanh AnnhonTay,CuChi PhamvanCoi,CuChi PhumyHung,CuChi LinhXuan,ThuDuc 15-30 15-30 15-30 15-30 15-30 15-30 15-30 15-30 1,74 3,18 0,42 0,27 0,16 0,71 2,05 0,48 Departmen t R&D CASE, Vietnam
B-ON AQUATIC PRODUCTS
Year 197 3 Sample location DongNai river Saigon river CanGio coast Sample Sheatfish Carp Sheatfish Shrimp Shrimp Frog Concentratio n 2,3,7,8 TCDD (ppt)/sample 668 540 70 42 18 79 Author Meselson & Baughma n Laboratory of analysi s USA 198 8 Hanoi city DongNai province DongNai province DongNai province DongNai province Sheatfish Sheatfish Sheatfish Snake Tortoise -Muscle -Gallblader -Liver -Ovary 0.13 0.33 0.46 11.58 1.3 2.2 19.0 60.2 K.Olie et al Holland
Year 199 3 Sample location Hue province DongNai province HoChiMinh city Sample Fish Fish, eal Fish, eal,crab Concentratio n 2,3,7,8 TCDD (ppt)/sample Total: 14 samples with averagetcdd = 0.77 Author Committee 10-80 Laborator y of analysis Holland Germany 200 2 CanGio,HCM city CuChi,HCM city Shrimp Oyster Arca Crab Eal Sheatfish Not detected (LOD=0.1) Not detected (LOD=0.1) Not detected (LOD=0.1) 0.18 0.10 0.31 CASE, HoChiMinh city Vietnam
OBSERVATION AND CONCLUSION
Samples of fish, shrimp,frog collected in the early 1970s showed very high levels of dioxin. This evidence confirming that dioxin had entered the food chain in Dong Nai and CanGio In the late 1980s, the levels of dioxin in fish decreased but still higher than those of reference sample in Hanoi city. Especially, concentration of TCDD were very high in the nake and tortoise sample
In the early 1990s, the average level of dioxin in some aquatic produits were still higher than normal level of Hanoi sample 0.77ppt/ 0.13ppt In the early 2000s, ours results showed that the concentration of TCDD were normal in comparison with those of the same type of sample in the foreign country
For soil samples, we received same results, the level of dioxin decreased from 45ppt in the late 1980s to 3.18ppt in 2002, the contamination of dioxin on the Cangio district still higher than others areas of HoChiMinh city 3.18/ 0.16
REFERENCES
1-NATIONAL ACADEMY OF SCIENCES; The effects of herbicides in South Vietnam; Part A: Sumary and Conclusions; Washington D.C; p-s-3; 1974 2-NORMAN, C.,Academy reports on Vietnam s herbicide damage; Nature, London; 248;p.186-188,1974
3-LE CAO DAI et al.; A comparison of infant mortality rates between Vietnamese villages sprayed by defoliants in wartime and one unsprayed village; Paper presented at herbicides in war, Hanoi, November, 1993 4-BAUGHMAN. R.,AND MESELSON.M., An analytical method for detecting TCDD (Dioxin): Levels of TCDD in samples from Vietnam; Environmental Health perspective 5; p.27-36 ;1973
5-NGUYEN DUC HUE et al., Analytical results of 2,3,7,8-TCDD in some soils sample in the South vietnam. 2nd International symposium report, Hanoi, November 1993 6-M.MATSUDA et al., Herbicides in war. The long term effects on man and nature, p.61-63, Hanoi, November, 1993
7-OLIE.K., et al; Chlorinated dioxin and dibenzofuran levels in food and wildlife samples in the North and South of Vietnam; Chemosphere Vol 19, Nos 1-6; p.493-496, 1989 8-CASE of HoChiMinh city; An investigation on PCDDs-PCDFs levels in soils, food and aquatic products in HoChiMinh city, Vietnam; September 2003
Vice Director Dr. Dinh Cong Tuan