A new source of fuel in aging Japan: adult incontinence
The restorative waters that flow into the public baths in this town near the coast of western Japan originate from hot springs more than two-thirds of a mile below ground. At the surface, before the water bubbles out of the spouts, it is further heated to 107 degrees Fahrenheit an ideal temperature for cleansing and soaking weary muscles.
But unbeknown to most bathers, the boiler heating the water runs on a fuel with the uncleanliest of origins: pellets recycled from soiled adult diapers.
In rapidly aging Japan, more diapers are used by older, incontinent people than by babies. As the country groans under the weight of ever-rising mountains of this waste, the town of Houki has become a pioneer in trying to reduce it. By recycling the diapers, which represent about onetenth of the town’s trash, it has diverted garbage that would otherwise be dumped in incinerators and add emissions to the atmosphere.
With many other nations facing a similar demographic implosion, adult diaper waste is a stealthy challenge that looms alongside labor shortages in nursing homes and insufficiently funded pension systems.
“When you think about it, it is a difficult and big problem,” said Kosuke Kawai, a senior researcher at the National Institute for Environmental Studies. “Japan and other developed countries will face similar problems in the future.”
In Houki, a town of just over 10,500 people in Tottori prefecture, officials were worried about the fast-growing diaper waste and looking at the costs to upgrade an outdated
incinerator. They decided to convert one of the town’s two incinerators into the diaper recycling plant and produce fuel that would help reduce natural gas heating costs at the public bathhouse as well.
At the baths, there is nothing advertising the provenance of the boiler fuel. Satomi Shirahase, 45, who was visiting with her husband from Kyoto, was unperturbedwhenshelearned of the source of the heat.
The recycling effort “sounds pretty good to me,” she said in the dressing room after hiking on nearby Mount Daisen, which strongly resembles the more renowned Mount Fuji. “I am not creeped out. It was good water.”
The diaper challenge is especially great in Japan, where more than 80% of the country’s waste goes to incinerators — higher than in any other wealthy nation — despite a near obsession with sorting trash. While most other sources of waste are declining in volume as the Japanese population shrinks, incontinence products for seniors are growing by the ton.
The amount of adult diapers entering the waste stream in Japan has increased by nearly 13%, to almost 1.5 million tons annually, in the past five years, according to data from the environment ministry. It is
projected to grow a further 23% by 2030, when those 65 and older will represent close to one-third of the population.
Because diapers contain so much cotton pulp and plastic, and swell to four times their original weight after soiling, they require much more fuel to burn than other sources of waste. That leads to costly waste management bills for local municipalities and high volumes of damaging carbon emissions.
And unlike with other products, such as single-use plastics, the use of diapers cannot be restricted without compromising sanitation and health care.
“We can easily eliminate straws and umbrellas on top of cocktails,” said Kremena M. Ionkova, a senior urban development specialist at the World Bank. “But we can’t eliminate diapers.”
Acknowledging the growing problem, Japan’s environment ministry convened a working group last year to discuss alternatives to incineration for diapers. A handful of other municipalities are following Houki and turning the diapers into fuel pellets, while some are experimenting with converting them into material that can be mixed with cement for construction or road paving.