Emissions from Yokkaichi, Japan

THE EVENT: Heavy pollution of the air in the Yokkaichi area, caused by petrochemical plants

DATES: 1950s-1970s

The industrial pollution of the air in and around Yokkaichi, Japan, caused widespread health problems for residents and led to landmark court cases and legislation aimed at preventing and reducing air pollution.

Yokkaichi, a port city on Japan’s Ise Bay, developed as a major industrial and center in the early twentieth century. The demands of World War II and Japan’s postwar recovery led to further industrial expansion in the area, and an oil complex known as the Yokkaichi Kombinato was created in the 1950s. Although the complex was an economic success, the it generated was soon linked to breathing difficulties and a variety of other health problems in area residents. Researchers found a high correlation between airborne sulfur dioxide and the incidence of bronchial asthma in children and of bronchitis in older people. Nevertheless, in 1963, a second industrial complex was opened in the region, and a third was added in 1973. In one district of Yokkaichi, airborne sulfur dioxide levels were found to be 800 percent above normal. In the early 1960s, nearly one-half of the area’s young children, nearly one-third of its elderly, and approximately one-fifth of its young adults had developed respiratory abnormalities.

In 1967 a group of Yokkaichi residents filed a suit against the Shiohama Kombinato, which ran one of the petrochemical complexes, and in 1972 the plaintiffs were awarded nearly $300,000 in damages. The award marked the first time that a group of Japanese companies had been held liable for damages, setting a precedent that made other companies vulnerable to such litigation. As a result of the case and ensuing controversy, in 1967 Japan’s government enacted a basic antipollution law. Within the next several years, additional laws spelled out redress rights for victims from the Yokkaichi area and for residents of polluted areas near Kawasaki and Ōsaka. Regulations requiring refineries to adhere to pollution-abatement policies were also strengthened.

As a result of such measures, by the mid-1970s airborne sulfur dioxide levels in the Yokkaichi region had decreased more than 60 percent, and the rate of respiratory complaints among area residents had declined sharply. By the 1990s nearly 100,000 Japanese citizens had been declared eligible for compensation under the new laws.

"Citizens' Image of Asthma and Their Actions During and After the Yokkaichi Lawsuit." European Society of Medicine, 18 Aug. 2022, esmed.org/MRA/mra/article/view/2964. Accessed 24 July 2024.

Takemoto, Yukimasa, et al. "History of Yokkaichi Asthma and Its Anti-Pollution Measures." Journal of Materials and Science Engineering, 2017, www.davidpublisher.com/Public/uploads/Contribute/599e4e477dabe.pdf. Accessed 24 July 2024.