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Press Release

Results of the Fourth Initial Environmental Risk Assessment of Chemicals

August 9, 2005

To prevent human health and ecosystem from adverse effects via environmental pollution of chemical substances, Ministry of the Environment (MOE) performed the fourth Initial Environmental Risk Assessment. The results were discussed at the ninth meeting of the Expert Committee on Chemical Substances of the Environmental Health Committee, the Central Environment Council. Consequently, it was agreed that one chemical substance each for health risk assessment and ecological risk assessment would be a candidate for further work.

In this assessment, continuous efforts were made to improve assessment methods and a new summary document for each assessed chemical, called "profile", would be prepared.


It is said that approximately 100,000 chemical substances are available in the world and about the half in Japan. Many of them are hazardous to human health and ecosystem and may cause adverse effects via environmental pollution.

To prevent these effects, it is necessary to assess environmental risk quantitatively, "the possibility that the chemicals which may cause an adverse effect on human health and ecosystem via environmental media such as air, water and soil may obstruct environmental protection", and to take appropriate risk reduction measures.

Therefore, the MOE started the Initial Environmental Risk Assessment in FY 1997. The results have been compiled into and publicized as "Environmental Risk Assessment of Chemicals" (Vol. I - Vol. III). For the chemical substances identified as "candidates for further work" in these assessments, appropriate administrative measures have been taken in cooperation with departments concerned.

2. Initial Environmental Risk Assessment

(1) Outline of Initial Environmental Risk Assessment
Initial environmental risk assessment of chemicals is performed according to the following ways: (i) "hazard assessment" - to specify hazard to human health and ecosystem and estimate the dose (concentration) - response (effect) relationship, (ii) "exposure assessment"- to evaluate the exposure of the chemical substances in environment to human and ecosystem, and (iii) to compare the results of both of the above assessment for risk characterization.

Considering risk management, "initial environmental risk assessment" for health risk and ecological risk is conducted to screen the chemical substances which may contain the possibility of relatively high environmental risk out of numerous ones. This initial assessment is conducted on the safe side to minimize the overlook of chemical substances with high environmental risk by utilizing maximum detected concentration for exposure assessment and information with higher sensitivity for hazard assessment.

(2) Chemical substances subject to the assessment
Chemical substances subject to the assessment are the chemicals which are anticipated to have high priority for initial assessment. They are selected on the condition that they have not been conducted risk assessments and risk management and that they are PRTR (Pollutant Release and Transfer Register) chemicals, designated chemical substances (currently Type II Monitoring Chemical Substances) in Chemical Substances Control Law, suspected endocrine disruptors and so forth.

(3) Number of the chemical substances subject to the assessment
For the implementation of the effective and systematic initial assessment, the following assessments were conducted.
Initial environmental risk assessment for health risk and ecological risk (20 chemicals).
Initial ecological risk assessment conducted separately from the initial environmental risk assessment (9 chemicals).

(4) Assessment methods
"Guideline of Initial Environmental Risk Assessment of Chemicals" was revised based on assessment methods which had been improved in the course of the third assessment. The revised guideline was utilized for the fourth assessment.

This assessment is improved by the following items.
Basic information of chemical substances subject to the assessment such as physicochemical properties were systematically collected and utilized for the model estimation and risk assessments.
The latest publicized PRTR data under the Law Concerning Reporting, etc. of Release to the Environment of Specific Chemical Substances and Promoting Improvements in Their Management (PRTR Law) was utilized for exposure assessment.
Reliability of collected data was evaluated more in detail and the result was reflected on the initial ecological risk assessment documents.
The necessity of data collection was discussed for the chemical substances whose risk could not be characterized currently because of insufficient information.

(5) Notes
The initial environmental risk assessment is conducted to select candidate chemicals for further work based on the limited information. Therefore, these candidate chemicals should not be directly interpreted as the substances which require risk reduction measures immediately.

3. Results of Initial Assessment

(1) Initial environmental risk assessment
The results of initial environmental risk assessment are shown in Table 1.

(2) Results of initial ecological risk assessment conducted separately from the initial environmental risk assessment
In addition to 20 chemicals of initial environmental risk assessment, 9 chemicals in PRTR chemicals, which are suspected their high ecotoxicity, were identified as the chemicals which require ecological risk assessment. The same assessment methods as those in initial environmental risk assessment were adopted in this assessment. The results of the chemicals whose ecological risk could be characterized are shown in Table 2.

4. Future Actions

(1) Providing information of assessment results
The assessment results is to be compiled into "Environmental Risk Assessment of Chemicals Vol. IV" with the "Profile", in which the outlines of assessment document for each assessed chemical is to be summarized, and be publicized on internet.

(2) Implementation of further work
For the candidate chemicals for further work, departments concerned is to collaborate each other to take measures including implementation of further work.
i. One candidate chemical for further work identified by initial health risk assessment.
Since risk of inhalation exposure to indoor air could be high, organization concerned is to be informed of this assessment result and their countermeasures is to be watched.
ii. One candidate chemical for further work identified by initial ecological risk assessment
With the accumulation for information of ecotoxicity, emission source, etc., further ecological risk assessment for this candidate is to have priority. Concretely, information acquired from the initial ecological risk assessment is to be utilized for the examination of additional environmental quality standards for water for preservation of aquatic organism.

(3) Information collection
For the chemical substances which will need collecting more information, and for those whose risk was not characterized, information is to be collected and the initial assessment is to be conducted.

(4) Systematic implementation of environmental risk assessment and its extensive application
i. Initial environmental risk assessment is to be systematically carried out in close cooperation with policies and investigation of environmental risk management for chemicals.
ii. Extensive scientific information in the initial environmental risk assessment process is to be utilized for many occasions such as selecting high-priority chemicals requiring risk management from PRTR chemicals, evaluating existing chemicals, and introducing GHS (Globally Harmonized System) for classification and labelling of chemicals in Japan.

(5) Future issues
i. Accumulation of physicochemical information is to be promoted and exposure assessment is to be improved by making use of PRTR data.
ii. The latest information of testing and assessment methods abroad, such as one in OECD, is to be obtained and the new information must be reflected immediately to initial environmental risk assessment. In the case an assessment method is revised, reassessment must be conducted for the chemicals for which initial environmental risk assessment had been already carried out. Based on domestic and international trend of risk assessment, assessment method is to be reexamined for initial ecological risk assessment.


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