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FORMATION OF THE PYRIDINE-ANALOGUE OF 2,3,7,8-TCDD

FORMATION OF THE PYRIDINE-ANALOGUE OF 2,3,7,8-TCDD. BY THERMAL TREATMENT OF CHLORPYRIFOS, CHLORPYRIFOS-METHYL AND THEIR MAJOR DEGRADATION PRODUCT 3,5,6-TRICHLORO-2-PYRIDINOL. Sakiyama T 1 , Weber R 2 *, Behnisch P 3 , Nakano T 4

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FORMATION OF THE PYRIDINE-ANALOGUE OF 2,3,7,8-TCDD

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  1. FORMATION OF THE PYRIDINE-ANALOGUE OF 2,3,7,8-TCDD BY THERMAL TREATMENT OF CHLORPYRIFOS, CHLORPYRIFOS-METHYL AND THEIR MAJOR DEGRADATION PRODUCT 3,5,6-TRICHLORO-2-PYRIDINOL Sakiyama T1, Weber R2*, Behnisch P3, Nakano T4 1Osaka City Institute of Public Health and Env. Sciences, Tohjo-cho 8-34, Tennoji-ku, Osaka 543-0026, Japan; 2 POPs Environmental Consulting, Ulmenstrasse 3, 73035 Göppingen, Germany 3BioDetection Systems BV (BDS), Kruislaan 406, 1098 SM Amsterdam, The Netherlands, 4Osaka University, Research Center for Environm. Preservation 2-5 Yamadaoka, Suita, Osaka 565-0871, Japan

  2. Content of Presentation** • Dioxins and pesticide history Japan • Dioxin and pesticide screening Australia (2010) • 2,4,5-T and chlorpyrifos as Twins? • Chlorpyrifos as • Formation of Pyridin analogue 2,3,7.8-TCDD in thermal experiments • Analytical behaviour of 2,3,7.8-TCDD-Py • Dioxin-like toxicity of thermal experiments • Possible practical experience 2,3,7.8-TCDD-Py

  3. g TEQ/Jahr 70000 PCDD/PCDF in PCP PCDD/PCDF in CNP 60000 co-PCB Other Chlororganics 50000 Industrial Waste Incineration Municipal Waste Incineration 40000 PCP 30000 IWI CNP 20000 MWI 10000 co-PCB 0 1988 1958 1963 1968 1973 1978 1983 1993 PCDD/F Contamination - A Historic Legacy ! Pesticide production, use and disposal have contributed significantly to polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) emissions in the past. Masunagaet al. 1998

  4. DIOXIN IMPURITIES IN PESTICIDE FORMULATIONS UNEP Emission Factor for 2,4,5-T Active Ingredient basis (AI) Formulation basis (FL) Holt et al. ES&T. 44, 5409–5415 (2010)

  5. O O Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl O O Cl Cl Cl Cl N N OR N Chlorpyrifos (R=Phosphor acid ester) 3,5,6-trichloro-2-pyridinol (R=H) 2,4,5-T und Chlorpyrifos-derivate - Dioxinrisiko In 2,4,5-T production and in product high 2,3,7,8-TCDD level OR 2,3,7,8-TCDD (Seveso-Dioxin; in Agent Orange) 2,4,5-Trichlorphenol (R=H) 2,4,5-T (R=Essigsäure)

  6. Structural similarity of Chlorpyrifos and 2,4,5-T Production Thermal Stress 2,3,7,8-TCDD (Seveso Dioxin) 2,4,5-Trichlorophenol (R=H) 2,4,5-T (R=Acetic Acid) (in Agent Orange) Production? Thermal Stress? Smiles Rearrangement Chlorpyrifos (R=Phosphor acid ester) 3,5,6-trichloro-2-pyridinol (R=H) 2,3,7,8-TCDD-pyridin-analogue

  7. Chlorpyrifos a High Volume Pesticide • Highest sales of chlorpyrifos of all organophosphate pesticides worldwide, and the third among all pesticides. • In 2010, the consumption of chlorpyrifos globally (converted into technical) reached 80,000 tonnes with CAGR of about 12% in the past five years (2005 to 2010). • Chinese production capacity was 116,000 tonnes (2010). Chlorpyrifos Chlorpyrifos-Methyl • In Vietnam about 37,000 tonnes of 2,4,5-T have been sprayed in total containing 366 kg TEQ to 1123 kg TEQ (Stellmann et al., Nature 422, 681-687 (2003)

  8. Thermal experiments with Chlorpyrifos and 3,5,6-trichloro-2-pyridinol • All pyrolysis experiments were carried out in sealed brown glass ampoules (10 ml; air) with about 2 mg of respective chemical chlorpyrifos, chlorpyrifos-methyl and the major degradation product of chlorpyrifos, 3,5,6-trichloro-2-pyridinol (TCPy) at temperatures between 300ºC and 380ºC. Chlorpyrifos Chlorpyrifos-Methyl Analytical grade chlorpyrifos, TCPy (both Dr. Ehrenstorfer GmbH, Augsburg/Germany) and chlorpyrifos-methyl (Wako Pure Chemicals, Osaka/Japan) were used.

  9. Thermal experiments with Chlorpyrifos and 3,5,6-trichloro-2-pyridinol Relative abundance of 2,3,7,8-TCDD-pyridine-analogues formed in thermal experiments (ampoule; air;15 min) *trans-isomer of 2,3,7,8-TCDD-Py; **cis-isomer of 2,3,7,8-TCDD-Py

  10. Condensation Products of Chlorpyrifos and 3,5,6-trichloro-2-pyridinol

  11. GC retention behaviour 2,3,7,8-TCDD-Py versus TeCDD

  12. DiCDD N-analogue DiCDD N-analogue TriCDD N-analogue TriCDD N-analogues 2,3,7,8-TCDD- N-analogues 2,3,7,8-TCDD N-analogues GC retention behaviour PCDD-Py PentaCDD N-analogue

  13. Clean-up column behaviour 2,3,7,8-TCDD-Py • The 2,3,7,8-TCDD-Py does not elute gogether with PCDD/PCDF in the following clean-up columns: (mention which columns • The Pyridin-analogues as base are adsorbed on the column and need specific elution in the clean-up • Therefore PCDD-Py are not transfered to GC/MS with (most?) current clean-up columns and would therefore not be detected in GC/MS (even in scan mode).

  14. Dioxin Toxicity (DR-CALUX) • Dioxin-like toxicities were assessed with the DR-CALUXTM assay. • Extremely high dioxin-like toxicity was detected from the treatment at 380ºC of TCPy (143,000 ng 2,3,7,8-TCDD bio-TEQ/g treated TCPy). • The 48 h kinetic indicated that the dioxin-like active compounds were stable.

  15. Conclusion/Recommendation • 2,3,7,8-TCDD-Py (having dioxin-like toxicity) is formed from chlorpyrifos, chlorpyrifos-methyl and in particular their major degradation product (TCPy) in heating experiments highlighting the need to investigate the formation of 2,3,7,8-TCDD-Py in real world scenarios with thermal stress e.g. • cigarette smoking (chlorpyrifos used in tobacco cultivation) • the combustion of post-harvest residues • fires in pesticide production or storage.

  16. Conclusion/Recommendation • Furthermore, 2,3,7,8-TCDD-Py is a high volume pesticide used for e.g. should be screened in chlorpyrifos pesticide formulations. With the background that 2,4,5-TCP based pesticides (Agent Orange, Pink, Purpule, White contained extreme high 2,3,7,8-TCDD levels). • Such assessments should include bio-assays for quantitative toxicity information on the extent of dioxin-like activity considering that also compounds other then 2,3,7,8-TCDD-Py seem to have dioxin-like activity in thermal treatment of chlorpyrifos.

  17. Thank you for your attention! Assessment: PFOA, PFXSi, PFHxS DeBDE,HBCDD,PBB, PBDD/F, HBBz, PBP, TBBPA, TBPAE, SCCP, MCCP, PCN, HCBD, OCS, PCP, PCNB PAHs, Nitro-PAH Halogenated PAHs PT-Pesticides, PT-Biocides PT-Pharmaceuticals PT-Siloxanes Sn-Organics Hg, Cd. Pb et al. “The dirty dozen” EvilEndosulfan PCDD PCDF PCB • PCBs • Dieldrin Aldrin Chlordane DDT Dieldrin Endrin HCB Heptachlor Toxaphene Mirex “The nasty nine”alpha-, beta-, gamma-HCH, PeCB, Chlordecone, PeBDE, OBDE, HBB, PFOS www.pops.int www.saicm.org www.ipen.orghttp://www.springerlink.com/content/0q10km8582605r1x/fulltext.pdf

  18. 2,4,5-T Herbicide mixtures used in Vietnam • Litres of herbicides sprayed over 1962–1971. The data are taken from the corrected HERBS file Stellmann et al., Nature 422, 681-687 (2003)

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