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Temporal Trend of POPs Residue in Japanese Agricultural Soils

Temporal Trend of POPs Residue in Japanese Agricultural Soils. National Institute for Agro-Environmental Sciences, Japan. Nobuyasu SEIKE. Preserved Soils.

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Temporal Trend of POPs Residue in Japanese Agricultural Soils

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  1. Temporal Trend of POPs Residue in Japanese Agricultural Soils National Institute for Agro-Environmental Sciences, Japan Nobuyasu SEIKE

  2. Preserved Soils Agricultural soils (paddy and upland) periodically collected from all over Japansince 1960s are preserved in the National Institute for Agro-Environmental Sciences(NIAES). Sampling Sites (15 sites) Dioxins and Dioxin-like PCBs 7 sites Air-dried and sieved (<2 mm) soils were preserved in polyethylene bottles at room temperature. Organochlorine Pesticides 15 sites

  3. Topics ● Temporal changes of dioxins and dioxin-like PCBsconcentrations associated with their sourcesin paddy soils ● Temporal changes of organochlrine pesticides concentrations in paddy soils ● In order to provide the factors for the decline of POPs in soils, half-lives for the disappearance of POPs in paddy soils were calculated.

  4. Dioxins (PCDD/Fs) PCDDs PCDFs (x + y = 1~ 8) (x + y = 1~ 8)

  5. PCDD/Fs concentrations ware increased drastically during the 1960s, began decreasing in the 1970s gradually. Temporal Change of PCDD/Fs Conc. in Japanese Paddy Soils Max. *Ministry of Environment and Ministry of Agriculture, Forestry, and Fisheries (2001) Mean Min. pg-TEQ g-1-dry Sampling Year

  6. Emission of PCDD/Fs, and OCDD 1,3,6,8-TeCDD Concentration OCDD Conc. 1368/1379-TeCDD Conc. PCP CNP Year Rapid increasing of PCDD/Fs concentrations are due to use of PCP and CNP

  7. PCDD/Fs produced from combustion processes was thought to be the major source before PCP was used The PCDD/F profiles in the paddy soils changed significantly after using PCP and CNP in the 1960s and the 1970s There were few significant changes in the PCDD/Fs profiles. Namely, another important PCDD/Fs source have not existed since 1980s. PCA Plot Site 2

  8. Quantitative Source Identification by CMB* *developed by Kashiwagi (2002) J. Appl. Statist. ~1960 (before PCP use): originated from combustion processes early-1960s ~ mid-1960s:PCP end-1960s ~:PCP and CNP (exceed 95%)

  9. Mass Balance of PCDD/Fs in Japanese Paddy Fields (1958-2000) Half-lives: 17.6 yr *Runoff : 2% / yr *Masunaga et al. ES&T (2001) Cumulative Input Disappearance from Paddy Field *Ministry of Environment and Ministry of Agriculture, Forestry, and Fisheries Nationwide Survey* （1999-2002）

  10. Dioxin-Like PCBs non-ortho PCBs mono-ortho PCBs 12 Congeners Known major source - Commercial PCBs (Kanechlors) Total PCBs use in Japan 50 ×106 kg banned at 1974 - Combustion Processes

  11. PCDD/Fs pg-TEQ g-1-dry Dioxin-like PCBs Dioxin-like PCBs concentrations are decreased during 1970s, and then, began to increasing gradually. Year Temporal Trend of Dioxin-like PCBs Concentrations in Paddy Soils Max. Mean pg-TEQ g-1-dry Min. Year Dioxin-like PCBs concentrations were considerably lower than PCDD/Fs.

  12. The Ratio of #126 to ΣPentaCBs The ratio of #126 toΣPentaCBshave been increased since 1970s = Dioxin-like PCBs originated from combustion processes have been increasing gradually

  13. Organochlorine Pesticides (OCPs) Compounds Usage in Japan (A.I base) Banned Year 1975 1975 1975 1968 1986 1971 1971 1975

  14. HCHs DDTs Drins Temporal Change of OCPs Conc. in Japanese Paddy Soils Chlordanes HCB HPCLs Mirex Temporal changes in OCPs concentrations in paddy soils reflected the use of pesticides.

  15. Temporal Change of OCs Conc. in Human Breast Milk from Osaka, Japan

  16. Half-lives in Paddy Soils

  17. Kow vs Half-lives

  18. Correlations between Half-lives and

  19. Concluding Remarks ● In Japan, use of OCPs was already banned in the early 1970s. ● PCP and CNP was also banned in the 1990s. ● The content of PCDD/Fs is checked at the agricultural chemicals registration ● The emission gas controls on waste incinerators and improvements of incineration facilities have been imposed since end of 1990s by the Japanese government It is, therefore, expected that further POPs contamination on agricultural soilwill not occur, and POPs concentrations in agricultural soil as well as air, water and biota, will decrease gradually.

  20. Acknowledgments I thank Dr Otani, T. and Dr Eun, H. National Institute for Agro-Environmental Sciences, for useful discussions. This work was supported in part by a Grant-in-aid (Hazardous Chemicals and Environmental Research) from the Ministry of Agriculture, Forestry and Fisheries and the Ministry of Environment, Japan, respectively.

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