About 70 substances are thought to be hormone disruptors, including dioxin, polychlorinated biphenyl (PCB), and bisphenol A, a plastic material widely used in daily life. Dioxin, in particular, is found in large quantities in the atmosphere surrounding Japanese cities--about 10 times more than in the urban areas of the United States and Europe--because Japan mainly relies on incineration for garbage disposal, a method that greatly reduces the volume of waste.

Abnormalities in Reproductive Functions
The impetus for the current global concern in environmental hormones came in 1996 with the publication in the United States of Our Stolen Future, which became a bestseller. Among other things, the book by Theo Colburn, Dianne Dumanoski, and John Peterson Myers reported that the reproductive organs of male alligators in a U.S. lake polluted by agricultural chemicals were half the normal size and that the number of alligators had declined sharply. It also told of hermaphroditic carp in Britain thought to have been contaminated by decomposed detergent.

Many similar cases have been reported in and around Japan, such as female snails with male genitalia. Also, at a meeting of the Japan Fisheries Society held in Tokyo in April 1998, it was reported that 30% of male carp in Tokyo rivers had abnormal seminal glands and that male flatfish in the sea off Tokyo's coast had been producing egg-yolk protein, which is a characteristic of females. A suggestion was made that these creatures in the wild were affected by environmental hormones.

As for how environmental hormones have affected humans, medical researchers at Teikyo University announced in March that a survey of the sperm of 34 men in their twenties revealed that only one man cleared all the standards of the World Health Organization for sperm volume, density, liveliness, and other factors, raising speculation that environmental hormones might be involved.

Surveys conducted by research institutes on polychlorinated containers, such as nursing bottles and tableware for infants and schoolchildren, have all revealed that when hot water, oil, or alcohol is poured on them, they produce the suspected environmental hormone bisphenol A. Although concentrations were lower than the level allowed by the Food Sanitation Law, concern is spreading among parents and others.

Government Gets Involved
Alarmed by the situation, the government has begun encouraging research in earnest. In 1997 the Ministry of Health and Welfare published the results of a survey conducted on 1,496 incineration facilities nationwide, revealing that many of these facilities were emitting abnormal quantities of dioxin into the atmosphere. The Environment Agency has conducted animal experiments to study the relationship between dioxin and reproductive functions. The government will also set up a special research facility using allotments from a supplementary budget to enhance knowledge of environmental hormones, carrying out a comprehensive survey of the air, soil, water, and living creatures around Japan to fully ascertain the kinds of pollutants the nation's residents are being exposed to.