Japan plans to make it mandatory to charge for plastic shopping bags at supermarkets, convenience stores, drugstores and department stores as the country combats marine pollution from plastic waste.

Environment Minister Yoshiaki Harada said at a news conference Monday his ministry plans to introduce a new law banning the practice of providing single-use plastic bags for free, while leaving the price of a plastic bag up to retailers.

“The proportion of plastic bags among plastic waste is not big, but charging would be symbolic” of Japan’s efforts to reduce such waste, said Harada.

“We should do it in time for the Tokyo Olympics,” Harada added.

On Tuesday, Harada said Prime Minister Shinzo Abe told him the measure is following the right direction and urged him to “thoroughly listen to the opinions of the people.”

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Japan produces the largest amount of plastic waste per capita after the United States and has lagged behind other countries in curbing the use of plastics.

The ministry expects retailers to charge between several yen to ¥10 per bag. Harada said the price should be effective in reining in the use of plastic bags.

The ministry also intends to request that retailers put the revenue toward environmental measures including afforestation and spreading awareness about marine pollution.

In addition, it will consider whether to expand targeted retailers to include small and midsize business operators, and to exclude biodegradable plastic bags.

Charging for plastic bags was among the measures included in the ministry’s draft strategic plan on plastic resource recycling compiled last year, but the specifics had been left undecided.

Over 8 million tons of plastic waste is estimated to flow into the oceans every year and cause microplastic pollution, in which tiny pieces of degraded plastic absorb harmful chemicals and accumulate inside fish, birds and other animals as they make their way up the food chain.

Among retailers, supermarkets have taken the initiative in moving away from free plastic bags, while convenience stores, where customers tend to visit the stores without reusable bags, are now looking to replace plastic bags.

Seiyu has been charging for plastic bags in all stores since 2012, and Aeon Co. made all of its stores charge for plastic bags by 2013. Ito-Yokado Co. and York Benimaru Co., both of which are affiliates of Seven & I Holdings Co., have also been implementing the same practice.

Seven & I Holdings announced in May its plan to completely stop the use of plastic bags by 2030. In April, 7-Eleven stores in Yokohama started offering paper bags in addition to plastic bags, with plans to proceed with plastic bag alternatives depending on their practicality.

Lawson Inc. is seeking to develop new reusable bags to catch up with the environmental trend.

Convenience stores and supermarkets are not the only sources of plastic bags. “It is necessary to gain the understanding of the various bodies concerned” in order to completely ban the use of such bags, an Environment Ministry official admitted.