FY 2003 Status of Air Pollution

September 10, 2004

The Ministry of the Environment published the air pollution monitoring results in FY 2003. In accordance with the Air Pollution Control Law, state of air pollution is constantly monitored throughout Japan at 2,101 monitoring stations by prefectural and ordinance-designated municipal governments. As of March 31, 2004, there are 1,660 ambient air pollution monitoring stations (hereinafter referred to as the "APMSs") and 441 roadside air pollution monitoring stations (hereinafter referred to as the "RAPMSs").

1.   Nitrogen dioxides (NO₂)

The environmental quality standard (EQS) achievement rate of NO₂ is relatively high just like FY 2002. The achievement rate is 99.9% for APMSs and 85.7% for RAPMSs. It improved slightly compared to FY 2002 (99.1% for APMSs and 83.5% for RAPMSs) (Table 1, Fig. 1-1). There is no major change in the annual average (Fig. 1-2).

2.   Suspended particulate matter (SPM)

Compared to FY 2002, the EQS achievement rate of SPM has improved. The achievement rate is 92.8% for APMSs and 77.2% for RAPMSs (52.5% for APMSs and 34.3% for RAPMSs for FY 2002) (Table 2, Fig. 2-1). In recent years, the annual average concentration has decreased slightly (Fig. 2-2).

3.   Photochemical oxidant (O_x)

The EQS achievement rate for O_x is only 0.3% combining APMSs and RAPMSs. The achievement rate is still extremely low (Fig. 3-1). On the other hand, the number of days on which the O_x warnings are issued decreased compared to FY 2002 (Fig. 3-2).

4.   Sulfur dioxide (SO₂)

The EQS achievement rate for SO₂ is 99.7% for APMSs and 100% for RAPMSs. The EQS is achieved in the majority of the monitoring stations in recent years (Figs. 4-1 and 4-2).

5.   Carbon monoxide (CO)

The EQS for CO is continuously achieved at all monitoring stations (Fig. 5).

Based on the monitoring results, the Ministry of the Environment will further enhance the comprehensive efforts to have an early achievement of EQSs through taking measures for emission from factories and business establishments, automobile exhaust gas, dissemination of low-emission vehicles, etc.

The Ministry of the Environment is providing real time information on nationwide status of air pollution obtained by Atmospheric Environmental Observation Regional System (nickname Soramame-kun) through the Internet and cellular phones.

Soramame-kun (only in Japanese)	http://w-soramame.nies.go.jp/
Cellular phones (only in Japanese)	http://sora.nies.go.jp/i/ (i-Mode) http://sora.nies.go.jp/j/ (J-SKY) http://sora.nies.go.jp/ez/ (EZ-WEB)

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* Table 1	Changes in Number of Valid Air Pollution Monitoring Stations, Number and Rate of Those Which Achieving Environmental Quality Standard (EQS) for Nitrogen Dioxide
* Fig. 1-1	Changes in Achievement Rate of Environmental Quality Standard for Nitrogen Dioxide
* Fig. 1-2	Changes in Nitrogen Dioxide (NO2) Concentration
* Table 2	Changes in Number of Valid Air Pollution Monitoring Stations, Number and Rate of Those Which Achieving Environmental Quality Standard (EQS) for Suspended Particulate Matter (SPM)
* Fig. 2-1	Changes in Achievement Rate of Environmental Quality Standard for Suspended Particulate Matter
* Fig. 2-2	Changes in Annual Average Concentration of Suspended Particulate Matter
* Fig. 3-1	Changes in Number of Monitoring Stations by Photochemical Oxidant Concentration
* Fig. 3-2	Changes in Number of Days of Photochemical Oxidant (Ox) Warning Issued
* Fig. 4-1	Changes in Achievement Rate of Environmental Quality Standard (EQS) for Sulfur Dioxide
* Fig. 4-2	Changes in Annual Average Concentration of Sulfur Dioxide
* Fig. 5	Changes in Annual Average Concentration of Carbon Monoxide