The Yomiuri ShimbunThe Land, Infrastructure, Transport and Tourism Ministry will embark on an investigation into the extent to which tiny plastic pieces, known as microplastics, are contained in sewage from ships in order to prevent marine pollution, The Yomiuri Shimbun has learned.
Plastics drifting in the sea do not completely decompose and it is feared that they are eaten by fish and other marine life, causing adverse effects on the ecosystem. The ministry plans to include costs related to the fact-finding survey in its initial budget for fiscal 2019, according to sources.
Microplastics are broken down mainly by ultraviolet rays and waves into 5 millimeter pieces or smaller. An international treaty bans the discharge of sewage from a ship directly into the sea if it contains garbage that includes plastic or excrement.
However, there is no regulation for the discharge of “gray water,” daily-life sewage generated by passengers on cruise ships and ferries or crew members on fishing boats and cargo ships when they take a shower or wash their face on vessels. Therefore, gray water is often released into the ocean.
It is said that some face wash and body soap contain very fine particles of microplastics as exfoliation agents. The ministry’s survey will collect gray water from ships for examination by a special institute. It will also examine any flow into the sea of plastic particles contained in the materials coating ships.
According to the ministry, following an increase in the number of foreign tourists visiting Japan from South Korea, China and other countries, the number of cruise ship calls to Japan has increased by about 2.5 times from five years ago to 2,764 in 2017.
Due to the economic growth of emerging economies, the number of cargo and passenger ships in the world has been on the rise. The volume of microplastics is believed to be on the rise along with this increase in the number of ships.
Atsuhiko Isobe, a professor of marine physics at Kyushu University’s Research Institute for Applied Mechanics, said: “Tiny garbage such as fine particles of exfoliation agents contained in face wash and other cleansers, as well as polyester lint, are not fully recovered and are released into the sea from ships. No data is available on how much of this type of garbage has been discharged so far. In that sense, it’s meaningful to conduct such a survey.”Speech