Citizen Participatory Dioxin Monitoring Campaign by Pine Needles As Bio-Monitor Of Ambient Air Dioxin Pollution

The needle-type leaves of Japanese black pine trees (hereafter abbreviated as pine needles) have been used as an effective bio-monitor of ambient air pollution. Miyata Laboratory of Setsunan University has reported that the pine needles accumulate PCDDs and PCDFs (hereafter abbreviated as D/F) through photosynthesis and respiration during their lifetime. On the basis of this study, we have revealed the correlation between ambient air and pine needle concentrations to be estimated at or near 1:10 by analyzing long term continuous ambient dioxin monitoring data and that of pine needles sampled from the same area as ambient air in the Kanagawa Prefecture in 1999. Since then, the citizen groups of each local area all over Japan have started monitoring the ambient air dioxin concentration levels by using pine needles. Samples analyzed during these 5 years totaled more than 650 throughout Japan. The results of these citizen participatory environmental monitoring activities are the tremendous effects achieved in reducing the dioxin levels. This occurs through observation of the dioxin emission sources such as Municipal Solid Waste Incineration Plants as well as the Industrial Waste Incineration plants, which exist in numbers exceeding several thousands in Japan. This short paper will present the results of 56 municipalities of western Japan where ambient air dioxin levels have improved steadily against local averages during these 5 years.