Across Japan, as gusty wintry winds give way to balmy breezes and the birds of spring begin to chirp, this is the sound of the season.

Japanese are expected to be sneezing more and more frequently over the next few months, with forecasters predicting an unusually high volume of pollen from cedar and cypress trees. The problem exists in the countryside, and also in the cities.

Japan's Environment Ministry says the pollen count is expected to be 13 times higher than last year in Tokyo, and 23 times higher in Osaka - matching levels seen during the miserable spring of 1995.

Cedar and cypress allergies are so prevalent this time of year that the pollen count becomes part of the daily weather report.

When they hear the news, millions of Japanese will don surgical masks and plastic goggles. In some communities between one-fourth and one-half of the population is estimated to be allergic to pollen from one or both of the offending trees.

These pollen allergies are relatively new to Japan. The first cases were not even reported until the early 1960s. A decade before that, Japan carried out a huge reforestation effort. By the time it was completed, cedar trees covered 12 percent of the Japanese archipelago, resulting in huge waves of pollen wafting through the air.

While Japan was planting the trees, it was also modernizing. Dr. Ruby Pawankar teaches at the Nippon Medical School and is on the Board of Directors of the World Allergy Organization. She says improved hygienic conditions are probably to blame for the Japanese becoming sensitized to pollen on such a wide scale. "There has been a reduction in infections, and that's what we call the hygiene hypothesis. So when the infections decrease, the suppressive factor is removed. The tendency to be more exposed to becoming allergic is increasing. Other factors are, like, urban style of living, wall-to-wall carpeting, closed houses with less ventilation, also dietary changes," she says.

The pervasiveness and severity of this spring's pollen count is forecast to take a significant economic toll. Toshihiro Nagahama is senior economist at the Dai-Ichi life insurance company's research institute. Mr. Nagahama says if this season's pollen forecast is accurate, Japan's gross domestic product will be pushed down six-tenths of a percent on an annualized basis.

The research institute expects that millions of Japanese, holding tissues at the ready for weeks on end, will generally just want to curl up in a ball - and sneeze. Mr. Nagahama, who suffers from cedar pollen allergy himself, says leisure and travel spending will be the hardest hit - down nearly four percent - and spending on food will drop more than two percent.

Dr. Pawankar estimates that pollen allergies cost Japan several billion dollars a year. She says it would be even higher, except that the Japanese appear so reluctant to call in sick. "If you look at the Japanese culture, people are so dedicated to the work, so the absenteeism from any disease is relatively less…. However, if you look at the direct costs, on an average, is about, say, $2 billion and the indirect costs - that is due to absenteeism - is about, say, $0.6 to $1 billion.

There is an upside to this allergy epidemic - if you happen to be making or selling drugs for the treatment of allergy symptoms. Japanese spend $2 billion a year to try to alleviate their suffering, about 20 percent of global sales.

Researchers say they are hard at work trying to reduce the nation's misery. The Agriculture Ministry says it is even considering allowing the first genetically modified product to be grown in Japan: a new strain of rice, containing a gene that produces the allergy-causing compound. Eating the rice would allow the body to build up a gradual resistance - similar to taking a series of allergy shots.

One of the most promising solutions, however, would get right to the root of the problem - scientists are working to grow cedar and cypress trees that produce no pollen.