## (7) Dioxins Emission Control

### A. What Are Dioxins?

Dioxins are substances generated naturally in the process of substance incineration (by-product).

Polychlorinated dibenzo-para-dioxin (PCDD) has 75 types of isomers, polychlorinated dibenzofuran (PCDF) has 135 types of isomers, and coplanar polychlorinated biphenyl (coplanar PCB) has a dozen types of isomers. Among these types of isomers, 29 types are regarded as being toxic.

### B. Position of Waste Incinerators in the Dioxin Problem

The main generation source of dioxins is garbage incineration. In addition to this, there are various generation sources, such as electric furnaces for steelmaking, cigarette smoke, and automobile emissions. It is said that dioxins are also generated in the natural world by forest fires, volcanic activities, etc. In addition, a research report says that dioxins contained in once used PCB and some types of agrochemicals as impurities may be accumulated in the environment, such as in mud found at the bottom of rivers or the sea.

The movement of dioxins after they have entered the environment is not known clearly. However, it is known, for example, that dioxins that have stuck to particles in the air fall to the ground and contaminate the soil and water. It is also known that dioxins including ones that have already been accumulated in the environment over a long time, including bottom mud, are taken up by plankton, fish and shellfish and on through the food chain into other animals.

### C. Details of the Dioxin Problem

In November 1983, newspapers drew attention to the dioxin problem when they reported that dioxins had been detected from ashes in a municipal solid waste incinerator.

The dioxin problem in waste treatment was discussed earlier, and measures were taken according to “Guidelines for Prevention, etc. of Dioxins Generation Related to Waste Treatment” (new guideline) created by the former Ministry of Health and Welfare in January 1997.

In the new guidelines, an emission concentration of $ 80 \, ng-TEQ/m^{3} $ was set as a criterion for judging the necessity of urgent measures. The new guidelines were positioned as a new structural standard and maintenance management standard, etc. through the revision in August 1997 of the Enforcement Ordinance of the Waste Management and Public Cleansing Law and the Implementation Ordinance of the same law, and was enforced in December of the same year. The Ministry of the Environment also decided to impose legal regulations on dioxins as designated substances of the Air Pollution Control Law and established emission control standards for emissions from incinerators and electric furnaces for steelmaking in December 1997, thereby regulating emissions of dioxins. Due to these regulations, dioxin concentration in emissions was required to be measured in December 1997, and the concentration standard to be met was applied in December 1998. In December 2002, it was decided that a stricter concentration standard would be applied.

In addition, the national government held its first Ministerial Conference on Countermeasures against Dioxin in February 24, 1999. In the Ministerial Conference on Countermeasures against Dioxin held in March 30, 1999, “Basic Guidelines of Japan for the Promotion of Measures against Dioxins” were laid down, which urged the national government as a whole to vigorously pursue various countermeasures, such as considerably decreasing the emission amount of dioxins. According to the guidelines in particular, it was decided that the total emission amount of dioxins would be reduced by “about 90%” by the end of March 2003, compared to the amount in 1997.

In 1999, the “Law concerning Special Measures against Dioxins” was enacted. In 2000, based on the same law, a target reduction amount was set by the “Plan for Reducing the Amount of Dioxins Emitted Through Business Activities in Japan”, and the plan required an emission inventory of dioxins to be drawn up every year. It was confirmed that the estimated emission amount of dioxins in 2003 was about 95% smaller than that in 1997, and the plan was evaluated because the target emission amount was achieved.

According to the report by the Central Environment Council (in November 2004) it was stated that the risk of dioxins needs to be continuously controlled, the plan was changed in June 2005 in order to take further measures for reducing dioxins, and a new reduction target for 2010 was set. The total estimated emission amount in 2008 fell below this target, and it is considered that dioxins have been steadily reduced (Table 2-12).

In addition, the total amount of dioxins emitted from waste incinerators in 2008 was about 98% less than that in 1997. This is probably because many of the incinerators that could not meet the emission standard and other structural and maintenance management standards, were either suspended or closed their operations due to the support measures, etc. related to tighter regulations and the development of standard-meeting incinerators, and because new incinerators that met the standards were developed. The achievement rate in fiscal 2008 of the environmental quality standards set according to the Law concerning Special Measures against Dioxins was 100.0% for the atmosphere, and the environmental quality standards were met for all measurement points.

## (8) Other Measures against Hazardous Wastes

In March 2009, a guideline on response to Pandemic Influenza was formulated for safe and stable treatment of wastes even during Pandemic Influenza season, and an infectious waste treatment manual (revised version) was summarized and notified in May 2009 in order to deal with revision, etc. of the Waste Management and Public Cleansing Law or the Infectious Disease Law.

In addition, proper treatment measures against wastes containing hazardous chemical substances such as mercury and persistent organic pollutants (POPs) have been studied responding to international movement.

Moreover, regarding wastes with safety from the viewpoint of radiation protection, information management system is operated to ensure the traceability.

## (9) Transboundary Movement of Hazardous Wastes

According to the “Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal” (hereafter referred to as the “Basel Convention”.