How is the air quality in Japan?

The below article talks about air quality and air pollution levels in Japan, the factors that contribute towards these levels, some policies issued or enforced to address air pollution concerns, along with some frequently asked questions about air quality in Japan. 

How is the air quality in Japan?

Current weather and air quality forecasts show that air quality in Japan is unhealthy, and is a cause of concern to vulnerable populations in the country such as the elderly, pregnant individuals, individuals diagnosed with chronic diseases, etc. While Japan does have periods of time within a year with good air quality, patterns show us that the majority of the year, the country experiences moderate to unhealthy levels of air quality. To address these concerns, the state government has taken several measures over the years, however, with rapid urbanization, the actions taken to address air quality are not in balance with the polluting activities in the state, thus does not adequately cover the air quality needs of the state and its citizens.  

Air Quality in Japan 

In accordance with global standards for air pollution and air quality levels set by the World Health Organization (WHO), Japan exceeds these limits and usually has air quality levels that are moderately poor to unhealthy levels of air quality (IAMAT, 2020). Air quality monitoring in the country shows that the dominant pollutant is particulate matter, and is currently two times higher than the recommended levels by the WHO (IQAir, 2022). 

The poor air quality levels in Japan can be attributed to rapid urbanization activities, haze, and pollutants blowing in from neighboring countries, petrochemical industries in the state, electricity generation plants, etc. Data shows us that the highest levels of air pollution in the state are experienced in the cities of Chiba, Tochigi, and Yamanashi. Other polluted cities include Kagoshima, Fukuoka, Osaka, Tokyo, and Okayama. 

Research tells us that air pollution in Japan originates from 3 sources: pollutants from industrial activities, vehicular emissions, and cross-border air pollution that blows into the country. While the country has taken significant measures to address these concerns are sources of air pollutants, the rapid development of the country has reduced the capacity for results towards cleaner air. Air pollution and air quality standards were not a concern for the country until the Meiji government when the government encouraged rapid development of the country, and this contributed to the intense economic growth in Japan by the 1950s. 

Power plants burnt large amounts of fossil fuels to generate electricity for citizens, as well as to provide for the growing industries in the state. This was crucial for a country that was recovering from war and helped to boost the national income. With increased pollution in the state, especially from sulfides, citizens began experiencing respiratory problems which came to be known as the Yokkaichi Asthma. As citizens started being more aware of the blatant destruction of natural resources and their health, movements to improve air quality had started to materialize in the country. Since then, various laws and policies have been implemented by the state through global and national agreements to address air quality concerns and achieve clean air. 

As mentioned earlier, though the country has taken large strides to address air quality concerns, levels of pollutants such as sulfur oxides and nitrogen oxides are still largely emitted from large industries and power plants. The laws in the state force these actors to install the required devices needed to filter out these pollutants from smoke or gas exhausts. However, increased particulate matter pollution is still observed widely in the country. The country also promotes activities such as desulphurization and flue gas denitrification to ensure healthier air quality. 

Technology to reduce emissions of air pollutants is advancing annually and so is their enforcement into different industries and general activities, but in order to reduce pollutants further, it is required to reduce the massive energy consumption in the country and reduce their dependence on fossil fuels for the same. Another concern for the country in air pollution is from the exhaust gases given off from vehicles, the increase in the number of cars owned, and the concentration of traffic in big cities, etc.

Japan Air Pollutant Standards and Limits

The Ministry of Environment in Japan under the Air and Transportation department has set put various laws, policies, and other regulations to curb air pollutants and control air quality levels in the state. In order to address these concerns in an encompassing manner, the ministry has set out regulations for different activities under air quality/ transportation, heat island, noise/ vibration, offensive odor, acid deposition, and dust & sandstorm. Below are the standards set by the ministry for different pollutants and their permissible concentrations. 

Source: MOE, n.d. 

SubstanceEnvironmental conditionsMeasuring method
Sulfur dioxideDaily average hourly values 0.04 ppmHourly values 0.1 ppm Conductometric method Ultraviolet fluorescence method
Carbon monoxideDaily average hourly values 10 ppmAverage hourly values for consecutive eight hour period 20ppm Nondispersive infrared analyzer method
Suspended particulate matterDaily average hourly values 0.10 mg/m3 Hourly values 0.20 mg/m3 Weight concentration measuring methods based on filtration collectionLight scattering methodPiezoelectric microbalance methodβ-ray attenuation method 
Nitrogen dioxideDaily average hourly values between 0.04 and 0.06 ppm Colorimetry employing Saltzman reagent Chemiluminescent method using ozone.
Photochemical oxidantsHourly values 0.06 ppm Absorption spectrophotometry Ultraviolet absorption spectrometryChemiluminescent method using ethylene.
BenzeneAnnual average 0.003 mg/m3 Preferred method: gas chromatograph-mass spectrometer 
TrichloroethyleneAnnual average 0.2 mg/m3 
TetrachloroethyleneAnnual average 0.2 mg/m3 
DichloromethaneAnnual average 0.15 mg/m3 
Dioxins(PCDDs, PCDFs, and coplanar PCBs)Annual average 0.6pg-TEQ/m3High-resolution gas chromatograph – high-resolution mass spectrometry (HRGC-HRMS). 
Fine Particulate Matter (PM2.5)Annual standard for PM2.5 is 15.0 μg/m3. 24-hour standard 35μg/m3.Mass measurement with filter sample collection.

Air Quality Policies and Regulations

A full list of all policies and regulations set up in Japan to address air quality concerns can be found here

The state government is continually introducing tighter regulations on primary sources of air pollutants such as automobile exhaust gases, industrial activities, power plants, etc. However, these have yielded unsatisfactory results in terms of capacity. Analysis conducted by the Ministry of Environment in the country shows that the rate of reduction of various pollutants is quite slow and has very low levels of change yearly. It is to be noted that the country did make significant reductions in the levels of particulate matter (PM10) and nitrogen dioxide and is very close to reducing PM2.5 levels, as well. 

Strengthening state policies and aligning to global agreements for climate ambition and action has put forward increased hopes to achieve clean air in the country. 

Frequently Asked Questions (FAQs): How is the air quality in Japan?

Which cities in Japan have the worst air quality?

Source: IQAir (2022, January 23). 

1Yokoshiba, Chiba137
2Hiraidemachi, Tochigi134
3Honcho, Tochigi117
4Tawarada, Chiba114
5Aramachi, Tochigi110
6Goi, Chiba107
7Yachimata, Chiba 107
8Kohokudai, Chiba105
9Tsuiheiji, Chiba105
10Chuo, Yamanashi102

Which cities in Japan have the cleanest air?

Source: IQAir (2022, January 23).

1Asahigaokacho, Hyogo0
2Gotsucho, Shimane0
3Ishigaki, Okinawa0
4Izumimachitakijiri, Fukushima0
5Obama, Fukui0
6Fukuicho, Tokushima1
7Higashikushira, Kagoshima1
8Hisage, Fukuoka1
9Iehisacho, Fukui1
10Ishibashicho, Fukui1

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International Association for Medical Assistance for Travellers (IAMAT). (2020, April 16). Japan General Health Risks: Air Pollution. Viewed on 01-23-2022. 

IQAir. (2022, January 23). Air Quality in Japan. Viewed on 01-23-2022. 

IQAir. (2022, January 23). Real-time Japan Most polluted city ranking. Live AQI City Ranking. Air Quality in Japan. Viewed on 01-23-2022. 

IQAir. (2022, January 23). Real-time Japan cleanest city ranking. Live AQI City Ranking. Air Quality in Japan. Viewed on 01-23-2022. 

Ministry of Environment (MOE). (n.d.). Air & Transportation. Viewed on 01-23-2022.  

Ministry of Environment (MOE). (n.d.). Environmental Quality Standards in Japan – Air Quality. Government of Japan. Viewed on 01-23-2022. 

United Nations Environment Program (UNEP). (2015, November 30). Air Quality Policies in Japan. Viewed on 01-23-2022. 

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