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Dioxins and Related Persistent Organic Pollutants (POPs)

Dioxins and Related Persistent Organic Pollutants (POPs). Professor, Division of Environmental and Occupational Health Sciences, University of Texas School of Public Health, Dallas, TX, USA Vietnam July 26-30,2010 Email: arnold.schecter@utsouthwestern.edu. Arnold Schecter, MD, MPH.

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Dioxins and Related Persistent Organic Pollutants (POPs)

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  1. Dioxins and Related Persistent Organic Pollutants (POPs) Professor, Division of Environmental and Occupational Health Sciences, University of Texas School of Public Health, Dallas, TX, USA Vietnam July 26-30,2010 Email: arnold.schecter@utsouthwestern.edu Arnold Schecter, MD, MPH

  2. Dibenzo-p-dioxins 2,3,7,8-tetrachlorodibenzo-p-dioxin

  3. Introduction • Dioxins are in all humans. • Elevated dioxins can persist in people 35+ years. • Patterns of dioxins varies by source: • Paper and pulp bleaching: TCDF and TCDD. • Agent Orange: 2,3,7,8-TCDD. • Pentachlorophenol: 5-8 Cl PCDD/PCDF. • Incineration: All congeners, especially OCDD. • PCB transformer fires: PCDFs predominate.

  4. Introduction (cont.) • Toxicity of dioxins understood by: • Toxicology – in vivo animal studies. • Toxicology – in vitro mechanistic studies. • Human epidemiology • “Safe” exposure level: • US EPA: 0.01 pg TEQ/kg BW per day x 70 yrs. • World Health Organization: 1 - 4 pg/kg BW per day x 70 yrs.

  5. Major incidents • Agent Orange in Vietnam: TCDD, 1962 - 1971 • Times Beach, USA: TCDD, 1970-1972 • Binghamton, USA: Transformer fire. PCB, PCDF/D 1981 • Seveso, Italy, TCDD: 1976 • Yusho rice oil poisoning, Japan: PCB, PCDF, 1968 • Yucheng rice oil poisoning, Taiwan: PCB, PCDF, 1976. • Belgium “dioxin” food poisoning: PCB/PCDF. 1990s.

  6. Diagnosis • Potential Environmental Exposure • Certain signs and symptoms (e.g., skin rash) • Blood Dioxin Measurements (By gas chromatography-mass spectroscopy)

  7. Known Dioxin Sources • Incineration (e.g., Household Garbage; Toxic Waste; Hospitals) • Herbicides (e.g., Phenoxyherbicides) • Pesticides (e.g., Chlorinated Phenols)

  8. Known Dioxin Sources (cont.) • Smelters (e.g., Aluminum and Copper) • Paper and Pulp Bleaching with Chlorine • Reservoir Sources (e.g., Sediment; Soil) • Cement kilns • Other

  9. Agent Orange • Agent Orange: Sprayed in Vietnam 1962-1971 • Spraying stopped due to science but mostly public outcry • Agent Orange was half 2,4-D and half 2,4,5-T • 2,4,5-T phenoxyherbicide contaminated with 2,3,7,8-TCDD (the most toxic dioxin) • Spraying was in parts of southern Vietnam only

  10. Ranch Hand Herbicide Spraying MissionsRed Area Indicates Sprayed Areas

  11. Barrels of Agent Orange

  12. History of Dioxin Exposure Determination • The Beginning: Harvard University • Research in the 1970’s: • Baughman, Meselson, Constable • Most toxic dioxin found in very high levels in: • Vietnamese nursing mothers’ milk (1345, now 1.0 parts per trillion, lipid) • Vietnamese fish from sprayed area • Not detected in US nursing mothers’ milk • US fish were not studied

  13. Vietnam/US Agent Orange History • 1983-92: Agent Orange Conferences (Vietnam) • 1984-2010: J. Constable & A. Schecter with the 10-80 Committee, Vietnam Red Cross and Committee 33

  14. Worldwide Research • Dioxin can cause: • Cancer • Immune deficiency • Nervous system problems • Reproductive problems • Developmental problems

  15. Worldwide Research (Continued) • Endocrine system damage • Skin pathology (including chloracne) • Liver damage • Elevated blood lipids • Heart attacks • Others

  16. Vietnam and U.S. Human Milk Dioxin (TCDD) Levels- 1970-80’s 1Baughman RW. Tetracholodibenzo-p-dioxins in the environment: high resolution mass spectrometry at the pictogram level. Cambridge, MA: Harvard University; 1974. PhD thesis. 2Olie K, Schecter A, Constable JD, Kooke RMM, Serné P, Slot PC, deVries P. Chemosphere. 1989; 19(1-6): 493-496. 3Schecter A, Dai LC, Thuy LTB, Quynh HT, Minh DQ, Cau HD, Phiet PH, Phuong NTN, Constable JD, Baughman R, Päpke O, Ryan JJ, Fürst P, Räisänen S. American Journal of Public Health. 1995;85(4):516-522.

  17. 2,3,7,8 TCDD levels in Vietnamese fish, crustaceans, and U.S. imported Vietnamese food 1Baughman RW, Meselson M. Environ Health Perspect. 1973;5:27-35. 2Schecter A, Pavuk M, Malisch R, Ryan JJ. Journal of Toxicology and Env. Health. 2003;66(15), 1391-404

  18. 2,3,7,8 TCDD and Dioxin Toxic Equivalents (TEQ) (lipid, ppt) in Vietnamese Pooled Blood Collected 1991-92 Schecter A, Dai LC, Thuy LTB, Quynh HT, Minh DQ, Cau HD, Phiet PH, Phuong NTN, Constable JD, Baughman R, Päpke O, Ryan JJ, Fürst P, Räisänen S. American Journal of Public Health. 1995;85(4):516-522.

  19. TCDD and TEQ in Food From Bien Hoa, 2003 ( pptww ) *ChannaStriatta (snakehead) Schecter AJ et al. J Occup Environ Med. 2003; 45:781-788

  20. Recent TCDD TEQ from Bien Hoa City and Aluoi Valley ‘hot spots’ (ppt) *EU Maximum Level 4 ppt (lipid) ** EU Max Level 8 ppt (ww) *** EU Max Level 1.5 ppt (lipid) 1. Dwernychuk L, et al. Chemosphere 2002. 47:117-137. 2 Schecter A et al. J Occup Environ Med. 2003; 45:781-788.

  21. Recent Dioxin concentrations (>90% TEQ 2,3,7,8-TCDD) in soil and lake sediment at three airport “dioxin hotspots” 1. Son LK, Sau TK, Lanh DN, Net NX, Truong NX, Minh NV, Tam TN. Organohalogen Compounds. 2007; 69:881-883. 2. Hoai, DX, Tam, TN 2009 Organohalogen Compounds 71, 85-87

  22. Da Nang Airbase1 (2009) • High TCDD levels in localized areas: • Soil up to 365,000 ppt TEQ • Sediment up to 6,270 ppt TEQ • Fish up to 3,000 • Vegetables up to 2,174 • However, newest data is not public. 1. Le Thi Haoi 2009 Organohalogen Compounds. Dioxin 2009

  23. Remediation Da Nang Airbase (2008) • $ Ford Foundation + USEPA + US Congress • Progress: • Construction of integrated facilities: • Preventing infiltration and land erosion • Monitoring • Special filtration systems • New reservoir and overflow dam • Warnings and bans in contaminated areas Canh, P.N. Organohalogen Compounds, Volume 70, 2008, 547-549.

  24. Bien Hoa City Residents (2008) • Knowledge of dioxins is limited • Unaware of routes of exposure • Little concern for health impacts of dioxins • Few are taking preventive measures • 65.5 % of people surveyed did not care or did not know the sources of foods that they consumed daily. Le Vu Anh et al. Organohalogen Compounds Volume 70, 2008, 535-538.

  25. Pesticides, PCDFs, and PCBs in Vietnam: Milk and Food (pptww) • α-HCH (α-hexachlorocyclohexane) • β-HCH (β-hexachlorocyclohexane) • γ-HCH (γ-hexachlorocyclohexane or lindane) • Hexachlorobenzene • DDT • DDT metabolites • PCBs • Dibenzofurans Schecter AJ et al. J Occup Environ Med. 2003; 45:781-788. Shelepchikov, AA et al. Organohalogen Compounds 2009; 71, 538-543

  26. Long Term Remediation Technologies for Dioxin Contamination After Fong VS, Coakley W, Farland W, Tien NQ, Ha DTC, L PH, Minh DV, Portier C, Brown D, Ball G, Killeen D, Sweeney MH, Son LK, Duong NN. Organohalogen Compounds. 2007; 69:898-901.

  27. Seveso TCDD Site at Present http://www.legambienteseveso.org/html/circolo/Foto/sito.jpg

  28. Current Vietnam/US Collaboration – Da Nang • Vietnam Ministry of National Defense, and Office of National Steering Committee 33, Hatfield Group, Ford Foundation • Assess environmental contamination and effectiveness of current mitigation efforts • Measure bio-accumulation of dioxin in the food chain and in people • Enhance awareness, government management, scientific exchange

  29. University of Texas Agent Orange and TCDD Research • US Vietnam Veterans, Agent Orange Sprayer Ranch Hands • TCDD alters human thyroid axis1 • TCDD associated with prostate and skin cancers2 • TCDD associated with lower incidence rates of benign prostate hyperplasia (BPH) • TCDD found in semen could suggest a possible mechanism for male-mediated adverse reproductive3 1 Pavuk M, Schecter AJ, Akhtar FZ, Michalek JE. Ann Epidemiol. 2003 May;13(5):335-43; 2Pavuk M, Michalek JE, Schecter A, Ketchum NS, Akhtar FZ, Fox KA. J Occup Environ Med. 2005 Apr;47(4):335-42; 3Schecter A, McCee H, Stanley J, Boggess K, Brandt-Rauf P. AJIM. 1996 (30):647-654.

  30. Other US TCDD Research Findings • WHO IARC: TCDD is a human carcinogen1 • WHO IARC: TCDD associated with multiple human pathologies1 • National Toxicology Program: TCDD is a human carcinogen2 • US EPA: Dioxin is a human carcinogen3 • US EPA: Dioxin causes multiple human effects3 1WHO IARC Monograph 69, PCDD/F, 1997 ; 2NTP. 9th Report of Carcinogens. 2000, Rev. 2001; 3US EPA Draft Dioxin Reassessment. http://www.epa.gov/ncea/pdfs/dioxin/nas-review/

  31. (US) “Veterans and Agent Orange, Update 2009” Institute of Medicine (IOM) US National Academy of Sciences (NAS) Sufficient Evidence of Association A. Soft-tissue sarcoma (including heart) B. Non-Hodgkin’s lymphoma C. Chronic lymphocytic Leukemia (CLL)(including B cell leukemias, such as hairy cell leukemia) D. Hodgkin’s Disease E. Chloracne

  32. Veterans and Agent Orange Update 2009, IOM/NAS (Continued) Limited Evidence of Association A. Laryngeal cancer B. Cancer of the lung, bronchus or trachea C. Prostate cancer D. Multiple myeloma E. Light Chain (AL) amyloidosis F. Early-onset transient peripheral neuropathy

  33. Veterans and Agent Orange Update 2009, IOM/NAS (Continued) Limited Evidence of Association G. Parkinson’s disease H. Porphyriacutaneatarda I. Hypertension J. Ischemic heart disease K. Type 2 diabetes (mellitus) L. Spina bifida in offpsring of exposed people

  34. Current Vietnam Activities (?) • Remediation- planning and implementation • Assistance to “Agent Orange Victims” • Education of the public, exposed and others • Agent Orange health research • Agent Orange remediation research • Agent Orange environmental research • Scientific publications and presentations • Government to Government cooperation

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