Estimated dioxin emissions in Japan dropped to between 2,620 grams and 2,820 grams in 1999, a roughly 63 percent fall from 1997 levels, according to Environment Agency figures released Thursday.

Agency officials attributed the decline to a new law addressing dioxin pollution that went into effect in January, as well as to stricter emissions standards for waste incinerators.

Publicly run waste incinerators accounted for around 50 percent of the total, or 1,350 grams of dioxin, while industrial waste incinerators emitted 690 grams and small-scale incinerators 481 grams.

All of these figures were down from 1997 and 1998 levels, according to the agency.

However, U.N. figures indicate that even with the reduction, Japan is almost certainly still the largest emitter of the chemical in the world.

As designated by the recently enacted dioxin law, coplanar PCBs (polychlorinated biphenyls) — chemicals similar to dioxins — were also included in the measurements.

The inventory incorporated coplanar PCBs for the first time. The agency said that if they had been included in the 1997 figures, it would have raised the total estimated amount of dioxin emitted that year to between 7,300 grams and 7,550 grams.

Government projections estimate that dioxin emissions should drop to around 600 grams by 2002, allowing the government to reach its stated goal of a 90 percent reduction in emissions from 1997 levels.

Sources of dioxin other than incinerators include metal production facilities, tobacco smoke, car exhaust, crematoriums and runoff from garbage dumps.

Dioxin is a known carcinogen and on the nation’s list of suspected endocrine disrupting chemicals. Such chemicals are believed to mimic hormones and impair immune functions, mental development in children and sexual function in humans.

Gas goal said feasible

The government can meet its pledge to reduce greenhouse gas emissions under an international climate treaty solely through domestic measures such as coal and carbon taxes, rather than relying on yet-to-be established international mechanisms, a citizen’s group said Thursday.

Kiko Network, a Kyoto-based nongovernmental organization that focuses on climate change, released a preliminary proposal contending that Japan can trim its greenhouse gas emissions by 6 percent from 1990 levels by reducing energy-related carbon dioxide emissions.