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Tokyo’s Air is Clearer Than Before, Weathermen Find

February 4, 1986

TOKYO (AP) _ Every three hours for the past 26 years weathermen have strolled out on the roof of their nine-story building to gaze out over Tokyo. They say the view, once blurred by pollutants, has vastly improved.

In 1960, when ″visual observatons″ by the Japan Meteorological Agency began, Japan’s postwar economic resurgence had filled the air with factory and auto emissions.

Since then, Japan has enforced some of the toughest air pollution control laws in the world, ″and the skies are much clearer,″ said Osamu Katsuyama, a weather agency official who has compiled data from the quarter-century of skygazing.

Tall buildings now block the view to the east and north, but to the south and west stretch the vast, moat-encircled grounds of the Imperial Palace, giving the weathermen a panoramic view of 50-story skyscrapers four miles to the west, the western foothills 18 away and the Tokyo Tower 2.5 miles to the south.

During winter, when the skies are at their clearest, snow-capped Mount Fuji juts up on the horizon, 60 miles to the southwest. At sunset on some crisp evenings, snow blowing off its 12,385-foot peak gives the impression that the long-dormant volcano is erupting.

In the first years of observation, these landmarks were often hidden behind chemical dust and other airborne pollutants. Katsuyama said that in 1961, observers could see 20 kilometers (12.4 miles) or more at the 9 a.m. sighting only two days the entire year.

In 1964, when visitors to the Tokyo Olympics found many residents wearing surgical-type face masks to ward off the fumes, there were still fewer than 10 clear days.

Visibility improved dramatically after 1968 when the strict air pollution control law was enacted. Through the 1970s, some of the world’s toughest restrictions were applied to auto emissions of carbon monoxide, nitrogen oxides and other gases.

In 1975, with energy conservation being spurred by the oil crisis, the weathermen could see 20 kilometers or more a record 113 days. In the 1980s, greater use of oil accompanying a return of plentiful supplies has pushed down the number of 20-kilometer days to about 80. Last year there were 87.

The weathermen make no claim to scientific veracity, acknowledging that results vary, depending on the eyesight of the viewer. The survey also does not take into account pollutants, such as nitrogen oxide, that are invisible.

″It’s always a judgment call,″ said Mikio Mayuzumi, who has been checking visibility along with other weather factors at three-hour intervals for the past five years. ″But we find that with experience there’s not that much difference in our conclusions.″

The viewings continue throughout the night, he said, with identifiable building lights used to measure distances.

Scientific data tends to bear out the weathermens’ views. Average levels of sulfur dioxides in the air dropped from 0.06 parts per million in Tokyo and other cities in 1967 to 0.012 in 1984. Carbon monoxide fell from 5.0 parts per million in 1968 to 1.0 while nitrogen dioxide has remained steady at a fairly low 0.025 level.

People complaining of discomfort from photochemical smog numbered 46,081 in 1975, but only 446 in 1982.

According to the Organization for Economic Cooperation and Development, Tokyo’s concentration of sulfur dioxide in 1983 was 29.5 micrograms per square meter, compared to 33.2 in New York, 60.27 in London, 61 in Paris and 88.7 in Rome.

For ″suspended particulate matter,″ Japan stood at 47.8 micrograms, on a par with New York’s 43.4 but well under Amsterdam’s 65.1 or Lisbon’s 159.4.

The national Environment Agency in February will begin a program under which volunteer groups throughout the country will make daily sightings of nearby landmarks and submit their findings to the agency.

Akira Shimazaki, an agency official involved in the program, said 88 towns and villages have agreed to join what is being called ″blue sky watch.″

″We want to get as many people as possible involved,″ he said. ″This is a good way to make people more aware of their environment.″

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