Sakiyama T 1, Weber R 2 *, Behnisch P 3, Nakano T 4 1 Osaka City Institute of Public Health and Env. Sciences, Tohjo-cho 8-34, Tennoji- ku, Osaka , Japan; 2 POPs Environmental Consulting, Ulmenstrasse 3, Göppingen, Germany 3 BioDetection Systems BV (BDS), Kruislaan 406, 1098 SM Amsterdam, The Netherlands, 4 Osaka University, Research Center for Environm. Preservation 2-5 Yamadaoka, Suita, Osaka , Japan

 Dioxins and pesticide history in 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

Masunaga et al Pesticide production, use and disposal have contributed significantly to polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) emissions in the past.

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

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

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

 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, (2003)

 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.

Relative abundance of 2,3,7,8-TCDD-pyridine-analogues formed in thermal experiments (ampoule; air;15 min) 2378-TCDD-pyridine- analogue (1)* 2378-TCDD-pyridine- analogue (2)** 300ºC340ºC380ºC 300ºC340ºC380ºC chlorpyrifos001x10^5003x10^5 chlorpyrifos- methyl 006x10^5003x10^6 3,5,6-trichloro-2- pyridinol 1x10^56x10^63x10^7 1x10^51x10^71x10^8 *trans-isomer of 2,3,7,8-TCDD-Py; **cis-isomer of 2,3,7,8-TCDD-Py

2,3,7,8-TCDD- N-analogues TriCDD N-analogue TriCDD N-analogues DiCDD N-analogue 2,3,7,8-TCDD N-analogues PentaCDD N-analogue

 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).

 Dioxin-like toxicities were assessed with the DR-CALUX TM 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.

 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.

 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.

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. PCDD PCDF PCBs Dieldrin Aldrin DDT PCB HCB Chlordane Heptachlor Mirex Toxaphene Endrin “The dirty dozen” “The nasty nine” alpha-, beta-, gamma-HCH, PeCB, Chlordecone, PeBDE, OBDE, HBB, PFOS Evil Endo sulfan

 Litres of herbicides sprayed over 1962–1971. The data are taken from the corrected HERBS file Stellmann et al., Nature 422, (2003)