earth’s surface, of which 10% to 20% has already degraded (desertified), and about 1% to 6% of people who live in the arid areas (approximately 20 million to over 120 million people) are estimated to be living in the areas affected by desertification. In addition to climate factors including drought and aridification, deforestation caused by overgrazing, excessive cultivation and excessive harvest of fuel wood, and salt accumulation on farmlands by inappropriate irrigation are also stated as causes of desertification. The backgrounds of this issue are related to social and economic factors such as population growth, poverty and the progress of market economy in the developing countries.

## F The environment in Antarctica

Antarctica is the part of the earth least destroyed by human activities or pollution, which has irreplaceable value as a place for global environment research. In recent years, increasing environmental impacts due to an increase in activities at research stations and tourism has become a concern.

## (2) Current status of the atmospheric environment

## A Photochemical oxidant

Prefectures and municipalities issue photochemical oxidant warnings and alarms based on the Air Pollution Control Law, in case the concentrations of photochemical oxidant increase and may cause damage.

## B Nitrogen oxide

The annual mean nitrogen dioxide level from all valid monitoring stations (monitoring stations with annual monitoring of at least 6,000 hours, the same hereinafter) in FY2007 was 0.013ppm at ambient air pollution monitoring stations (AAPMSs) and was 0.025ppm at roadside air pollution monitoring stations (RAPMSs). AAPMSs have nearly leveled off, and RAPMSs have

Figure2-3 Changes in the Number of Monitoring Stations by Photochemical Oxidant Concentration Level (AAPMSs and RAPMSs) (FY2003-FY2007)

Changes in the Number of Monitoring Stations by Photochemical Oxidant Concentration Level (AAPMSs and RAPMSs) (FY2003-2007)

Source: Ministry of the Environment, FY2007 Report on the State of Air Pollution

Source: Ministry of the Environment, FY2007 Report on the State of Air Pollution

showed a gradual improving trend (Figure2-4).

## C Suspended Particulate Matter (SPM)

The annual mean level for SPM in FY2007 from all valid monitoring stations was $ 0.024mg/m^{3} $ at ambient air pollution monitoring stations (AAPMSs) and was $ 0.027mg/m^{3} $ at roadside air pollution monitoring stations (RAPMSs), showing gradual improvements in recent years (Figure2-5).

The ministry consulted the Central Environment Council in December 2008, regarding the setting of the environmental quality standards (EQSs) for fine particulate matter (PM 2.5), and the “expert committee on environmental standards for Fine Particulate Matter” and the “expert committee on monitoring methods for Fine Particulate Matter” have been established and discussions have been progressed under the Council’s Atmospheric Environment Committee.

## D Hazardous air pollutants

According to the results of hazardous air pollutants monitoring research in FY2007, in terms of the four substances that have environmental quality standards in place, levels of benzene exceeded the environmental standards at 0.7% of monitoring points, however, the other three substances met the standards at all monitoring points. Out of the seven substances that have the guideline values set, nickel compounds

Figure2-5 Changes in Annual Average SPM Concentration (FY1974–FY2007)

Source: Ministry of the Environment, FY2007 Report on the State of Air Pollution