Dioxin: Levels high in incinerator-happy Japan
Last in a series
By MICK CORLISS
Take a look around you. Those disposable chopsticks that came with your lunch, the plastic container it came in, the credit card you used to buy itwhat do these all have in common?
They all likely contain chlorine or chlorine-based chemicals and will release dioxin when burned.
These repositories of chlorine will all eventually be thrown away. Some ultimately will find their way to a landfill in the mountains or on the coast. But chances are good that they will be burned like the overwhelming majority of Japans garbage, before being carted off to be buried out of sight and mind.
But even out of sight and out of mind might not be far enough.
On average, Japans air contains nearly 10 times the amount of dioxin found in other industrialized countries. This statistic is largely attributed to the countrys penchant for waste incinerationthe alleged source of roughly 90 percent of the estimated 5 kg or more of the toxic chemical released every year.
"It is hard to understand Japans dioxin situation today without looking at the past," said Masatoshi Morita, director of the National Institute for Environmental Studies and a foremost expert on dioxin analysis.
First discovered in Germany in 1872, dioxin is not manufactured and has no use. Dioxin is a catch-all word for a family of 75 chemicals that closely resemble each otherall chlorine-based and sharing the same basic carbon-oxygen framework.
Historically, dioxin was not an incinerator-related problem, Morita said. From the late 1940s until the 1970s, the dioxin problem was basically one of chemicals and pesticides.
However, in 1976, more than a century after it was concocted in a German lab, the seriousness of dioxin pollution grew when the substance was discovered in emissions from a municipal waste incinerator in the Netherlands.
Seven years later, Ryo Tachikawa, now president of Kochi University, detected the same phenomenon in Japan. "From this point, people began to realize that dioxin was not merely an issue of chemicals, but also a garbage issue," Morita said.
Incineration is a relatively new addition to Japans waste disposal repertoire.
After opening its borders to the West, Japan was inundated with more than trains, planes and new technology. It also opened itself to a variety of communicable diseases.
And the 19th centurys conventional method of disposalabandoning waste in the most convenient spot at handwas begrudgingly forsaken.
With industrialization, workers flocked to the cities. Limited space and a need for disease prevention prompted the government to embrace incineration.
But although its history is short, its legacy is strong: Japan has the distinction of being the worlds largest burner of garbage. And not just by a nose. Many observers would say Japan is far and away the most dioxin-polluted of any developed country.
Experts estimate that Japan is home to nearly 70 percent of the worlds waste incinerators. And nearly three-quarters of the nations waste is burned in these facilities.
Over time, the amount and content of Japans garbage has changed. Today on average, more than 1 kg of garbage is produced per citizen per day, and experts maintain that Japan probably has the highest percentage of polyvinyl chloride plastic in its municipal wastes of all industrialized nations.
In an effort to allay dioxin concerns, the government has tightened emission standards and devised a subsidy program for the construction of large incinerators that can operate continuously at high temperatures, which helps reduce dioxin emissions.
But it is important to grasp the scale of the problem to reduce dioxin emissions. To this end, the government is in a tizzy compiling an inventory, or calculation of emissions, of the toxin. A report is scheduled to be released in June in line with government guidelines announced in March.
"The new inventory will be much more accurate and reliable," said Yasuo Yanagibashi of the air pollution control division of the Environment Agencys Air Quality Bureau. This will in turn facilitate policymaking by clarifying exactly what steps must be taken, ensuring the gradual reduction of dioxin emissions, he added.
And while dioxin debacles of recent months have thrust the incineration industry into the limelight, this attention may shift with the government cracking down on the burning of garbage.
"If the government succeeds with its plan to cut emissions by more than 80 percent, I think the focus may shift to other (dioxin) emitterssuch as industry," said Kuniaki Makiya of the agencys Office of Environmental Risk Assessment.
Up to now, the government has estimated that about 5.3 kg of dioxin is emitted annually in Japana figure borrowed from a Kyoto University professor who calculated it in 1991 by simply applying emission information from the United States, where incinerators generally burn cleaner, to Japans volume of trash.
While 5 kg may not sound like much, animal testing has shown that just 1 gram of the toxin is enough to kill 10,000 people, according to Toshikazu Fujiwara, director of the citizens group Kanto Network to Stop Dioxin Pollution.
Fujiwara challenges the governments figure, arguing that citizens groups and professors generally believe it to be ridiculously conservative. They estimate the figure to be closer to 15 or 20 kg per year, he says.
Fujiwara and others said they are encouraged to see the government tackling the dioxin issue in earnest, but added they are alarmed at the way in which it is being carried out.
Although a regulatory net is gradually being tightened around dioxin emissions themselves, there are no restrictions on incinerator ash, which is known to contain very high levels of the toxin, according to Teiichi Aoyama, president of the Tokyo-based Environmental Research Institute, a private research firm.
In addition, the governments plan to consolidate incinerators into large-scale facilities is also problematic, according to Aoyama.
These need waste to operate, and this is bound to pose problems in rural areas where keeping a garbage supply big enough to run the facilities may be difficult. Eventually, the need to collect enough garbage to keep them running may snowball into a huge financial burden, critics say.
Ultimately, large-scale incineration is not the solution, agrees Fujiwara, who preaches the merits of a society that is PVC-free and where municipalities process their own waste.
Incineration at high temperaturesover 800 Cmay reduce dioxin emissions, but comes with a host of other problems, he said, such as increasing output of global-warming gases and heavy metals. Also, finding municipalities willing to accept such a facility and process neighboring areas trash will not be easy, he added.
Fujiwara also challenges the governments attempt to come up with a more accurate inventory of dioxin emissions data, maintaining that its survey method is fundamentally flawed.
Nearly half of the dioxin released by incinerators is released while they are warming up and cooling down, he said. But because government surveys are taken during peak operating hours, the levels recorded may be misleading, he added. "I really question whether this (new inventory) will translate into effective policy," Fujiwara said, stressing the need to look beyond incinerators for an effective solution.
Some municipalities, however, have reduced the amount of dioxin their incinerators release through extensive and aggressive recycling and garbage separation campaigns, he said.
"I am convinced that the increases in dioxin emissions are due largely to PVC products," he said, citing industries production patterns and societys consumption patterns as major obstacles to effectively whittling down dioxin emissions.
Clearly the dioxin problem is deeply rooted in our way of life. But with citizens and the government both clearly concerned, one unexpected byproduct of the potential dangers posed by this toxin may be a novel form of cooperation between the two to resolve this environmental dilemma.