Air Pollution's Long Reach: China To Japan

China's air pollution has been a cause for concern for its neighbouring countries, including Japan, which is downwind of China. In 2013, a serious air pollution event in China caused hazardous particulate matter (known as PM2.5) to drift across the sea to Japan, causing worry among residents about potential health risks. While some believe that China is a significant contributor to Japan's air pollution, others argue that Japan's pollution is largely generated within the country due to industrial production, vehicle emissions, and other factors. According to Hiroshi Tanimoto of Japan's National Institute for Environmental Studies, China's contribution to Japan's fine-particle pollution ranges from 40% in the Tokyo area to 60% in Kyushu, the closest region to China. Overall, it is clear that China's air pollution does reach Japan, and international cooperation is needed to address this issue.

Transboundary air pollution

Japan, due to its proximity to China, is impacted by China's air pollution. In 2013, a severe air pollution event in China raised concerns in Japan, as hazardous particulate matter (PM2.5) drifted towards Japan, causing health worries. This event was caused by stable atmospheric conditions and high aerosol pollutant concentrations in Chinese cities. While China's pollution dilutes by the time it reaches Japan, it still affects air quality. Japan's National Institute for Environmental Studies estimates China's contribution to Japan's fine-particle pollution at 40-60% in different regions, with about 10-20% of springtime ozone originating from Chinese emissions.

However, Japan also has domestic sources of air pollution, including industrial production, vehicle emissions, and thermal power plants. These sources have led to pollutants such as nitrogen oxides (NOx) and sulphur oxides (SOx), which are regulated by the Air Pollution Control Law. Japan has also experienced improvements in air quality over the years, with a "good" US AQI reading of 47 in 2021.

To address transboundary pollution, Japan and China have considered cooperation. Environment ministers from both countries have held talks to reduce airborne pollution, recognizing the impact on their respective nations. Additionally, Japan has sought to improve domestic air quality through measures such as emission controls and the expansion of public transportation.

Impact on Japan's environment

Japan's air quality has been affected by China's air pollution, with transboundary pollution from China contributing to ground-level ozone levels in Japan. This is due to the emission of pollutants such as nitrogen oxides (NOx) and volatile organic compounds (VOCs) from the combustion of fossil fuels, which are not significantly reduced due to cross-border pollution. In 2013, Japan experienced the impact of China's pollution when hazardous particulate matter (PM2.5) drifted across the sea, causing health concerns and reduced visibility. According to Hiroshi Tanimoto of the National Institute for Environmental Studies, China's contribution to Japan's fine-particle pollution ranges from 40% in the Tokyo area to 60% in Kyushu.

However, it is important to note that Japan also has its own sources of air pollution, including industrial production activities, vehicle emissions, and population density. The country has implemented regulations and technologies to reduce pollution, such as the Air Pollution Control Law, which mandates dust collectors and smoke exhausts in factories, and the promotion of emission control measures. As a result, Japan's air quality has been improving, with a US AQI reading of 47 in 2021, classified as "Good" by the World Health Organization (WHO).

The impact of China's air pollution on Japan has led to diplomatic discussions between the two countries, as well as with South Korea, which is also affected by Chinese emissions. The environment ministers of Japan, China, and South Korea have held talks to seek solutions and reduce airborne pollution in the region. Japan has also received inquiries from abroad about its contribution to addressing China's pollution problems.

While China's pollution has had a significant impact on Japan's environment, it is not the sole cause of Japan's air quality issues. Domestic sources of pollution, such as industrial activities and vehicle emissions, also play a role. Japan's historical context, particularly the rapid development of industry during the Meiji government's policy era, has contributed to the country's pollution challenges. However, with the implementation of regulations and technologies, Japan has been making progress in improving its air quality in recent years.

Japan's air quality in 2021

Japan's air quality has been a concern for the country since the Meiji government's policy era encouraged the rapid development of industry, with pollution intensifying during the period of high economic growth in the 1950s. In recent years, Japan has seen an improvement in air quality, with 2021 being no exception. At the beginning of 2021, Japan enjoyed good air quality with a US AQI reading of 47, which fell within the "Good" category according to World Health Organization (WHO) standards. This positive trend continued throughout the year, with COVID-19 restrictions further contributing to improved air quality.

However, Japan's air quality is not uniform across the country. Imari, Saga has been identified as the most polluted area in Japan, possibly due to the widespread manufacture of porcelain in the region. In contrast, Obihiro in Hokkaido is the cleanest city in Japan, with a recorded level of 24, also falling into the “Good" category.

While Japan's air quality has shown improvement, the country is still susceptible to external factors, such as air pollution from China. Research suggests that China's contribution to Japan's average annual fine-particle pollution can range from 40% in the Tokyo area to 60% in Kyushu, the region closest to China. This pollution consists of soot, ozone-forming compounds, and other pollutants, which can have a significant impact on Japan's air quality, particularly during specific events such as volcanic eruptions.

Despite these challenges, Japan has made notable progress in improving its air quality over the last three decades. From 2003 to 2018, Nagoya, Japan, experienced a decrease in PM2.5 concentration, indicating a positive long-term trend. Overall, Japan's air quality in 2021 reflected a continuation of the country's efforts to enhance its environmental conditions, with a combination of domestic policies and international influences shaping the air pollution levels experienced by its citizens.

Sources of Japan's air pollution

Japan's air pollution is caused by a combination of factors, including industrial production activities, vehicle emissions, and cross-border air pollution. While China's air pollution does reach Japan, it is not the sole contributor to Japan's air quality issues. Here is a detailed look at the sources of Japan's air pollution:

Industrial Production Activities

The industrial sector plays a significant role in Japan's air pollution. Since the end of World War II, Japan has experienced rapid industrialization, with a substantial increase in manufacturing activities. This growth led to a rise in pollutants emitted by factories, particularly those located on waterfront areas for increased production efficiency. The concentration of pollutant sources resulted in severe pollution-related diseases, including Minamata disease and Yokkaichi asthma. To address these issues, Japan enacted the Basic Law for Environmental Pollution Control to implement comprehensive and systematic pollution control measures.

Vehicle Emissions

Vehicle emissions, particularly from automobiles, are a significant source of air pollution in Japan. The combustion of fossil fuels releases harmful pollutants such as nitrogen oxides (NOx) and volatile organic compounds (VOCs) into the atmosphere, contributing to ground-level ozone formation. Japan has introduced regulations to tighten vehicle emission standards and promote the use of low-emission vehicles. Additionally, encouraging the use of public transportation, walking, or biking can significantly reduce emissions and improve air quality.

Cross-Border Air Pollution

Japan also experiences cross-border air pollution, particularly from neighboring countries like China. According to studies, China's emissions contribute to fine-particle pollution in Japan, with levels ranging from 40% in the Tokyo area to 60% in Kyushu, which is closer to China. The impact of Chinese emissions on Japan's ozone levels is also notable, with about 10-20% of springtime ozone attributed to Chinese sources. The pollutants from China add to Japan's local air quality issues, and the international nature of the problem makes it challenging to find collaborative solutions.

Domestic Sources

In addition to cross-border pollution, Japan also faces air quality issues from domestic sources. Population density, traffic congestion, and industrial activities in specific regions contribute to localized air pollution. For example, Fukuoka and Tokyo have experienced high levels of air pollution, with some residents questioning whether it is solely due to Chinese emissions or if domestic sources play a significant role.

Porcelain Manufacturing

The widespread manufacture of porcelain in and around Imari, Saga, has led to increased air pollution in the region. According to Swiss air monitoring company IQAir.com, Imari has the most polluted air in Japan, possibly due to the high-quality porcelain production for export worldwide.

International cooperation

Air pollution is a severe issue that affects people's health and the climate. It is the leading environmental risk to human health, causing approximately 7 million premature deaths annually. Women, children, and older persons are more vulnerable to the negative health impacts of air pollution.

China's air pollution, which is caused by a combination of factors, including the country's energy mix, unsustainable development patterns, and population density, has impacted neighbouring countries, including Japan and South Korea. The extent of China's contribution to Japan's air pollution has been a topic of discussion, with some studies suggesting that it accounts for up to 60% of fine-particle pollution in certain areas of Japan.

Recognizing the impact of transboundary air pollution, Japan and China have taken steps towards cooperation to address this issue. Japan has shared its experiences and technologies for combating air pollution with China through official development assistance (ODA) programs and projects aimed at raising awareness. The two countries have also established committees and forums, such as the Japan-China Joint Committee on Environmental Protection and Cooperation, to foster dialogue and collaboration. They have agreed to cooperate on monitoring and managing hazardous chemicals, waste management, and preventing the illegal transboundary movement of waste. Additionally, they plan to enhance cooperation through regional environmental initiatives, including the Tripartite Environment Ministers Meeting (TEMM) and the Northwest Pacific Action Plan (NOWPAP).

Looking beyond the bilateral relationship, there are international efforts to tackle transboundary air pollution. The UNECE Convention on Long-range Transboundary Air Pollution, with its 40 years of experience, serves as a platform for countries to collaborate and address common challenges. The establishment of the Task Force for International Cooperation on Air Pollution in 2021 further demonstrates the global commitment to addressing this issue through enhanced collaboration and information sharing.

In conclusion, while China's air pollution does reach Japan, the two countries have recognized the importance of international cooperation to mitigate this issue. By sharing knowledge, technologies, and best practices, Japan and China are working together to reduce transboundary air pollution. Additionally, their participation in regional and global initiatives underscores their commitment to finding solutions that benefit not only their respective countries but also the wider region and the world.

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