Environmentally sound management (ESM) practices on cleaning up obsolete stockpiles of pesticides for Central European and EECCA Countries

Pesticide use and deposition of pesticide production residues contribute to environmental PCDD/PCDF contamination, in particular on a historical scale. Despite potentially substantial quantities of PCDD/PCDF emission, and remaining depositions via this route, only limited information is available on the resulting environmental contamination load or pathways. The total dioxin emission from the use of pesticides in Japan during the past 40 years (1955-1995) was estimated to 540 tonnes of PCDD/PCDF or 250 kg of TEQ from PCP (with predominant OCDD/OCDF and other highly chlorinated congeners), and 380 tonnes of PCDD/PCDF or 210 kg TEQ from 2,4,6-trichlorophenyl-4’-nitrophenyl ether (CNP) (with 1,3,6,8/1,3,7,9-TCDD as dominant congeners). The PCDD/PCDF impurities from PCP and CNP pesticides still contribute a large part of today’s PCDD/PCDF contamination in Japanese soil and sediments. A comparison of PCDD/PCDF loads derived from PCP/CNP application and their deposition in sediments of the Tokyo bay showed that only a small portion of PCDD/PCDF agrochemical impurities have been deposited in the Tokyo Bay sediment during the past 45 yeas. This indicates that a large part of the PCDD/PCDF load still exists in the terrestrial soil or river sediments of this area, which results in future runoff into Tokyo Bay. This highlights the pertinence of assessing pesticide contamination and application history for the understanding of environmental PCDD/PCDF loads and risk assessment. Information from former pesticide production sites and associated landfills present another example for emissions of large quantities of PCDD/PCDFs to the environment in the past and future. In particular, the residues from production of various chlorinated pesticides (e.g. 2,4,5-T, PCP, PCPNa, HCH ) were contaminated with high concentrations of PCDD/PCDFs and were found to leach from deposits together with pesticides, other chlorinated aromatics and aliphatics. This highlights the necessity of monitoring, containment and possibly remediation of such hotspots. The present paper summarises and discusses available data and estimates from two case studies in Japan and Germany on pesticide application and production-derived PCDD/PCDF contamination in order to highlight the potential significance of such, predominantly past actions, to environmental PCDD/PCDF loads of the future.