[EPID] - Allergies To Cedar Pollen In Tokyo Double In A Decade

TOKYO, Dec 31 (Reuters) - A survey recently released by the Tokyo Metropolitan Government found that the number of people allergic to cedar pollen doubled over the past 10 years. Currently, one out of every five persons has such an allergy.

In the only previous survey of allergies, conducted by Tokyo's Environmental Health Division from 1983 to 1987, 10% of Tokyo citizens had allergies to cedar pollen.

The survey also showed that an increasing number of children and adolescents younger than 15 years of age suffer from pollen allergies, including a sensitivity to pollen from two kinds of grasses. The percentage of allergy patients in that age bracket in Chofu, one the surveyed areas, increased in the decade 1987 to 1997 almost threefold -- from 7.6% to 21.5%.

In 1996, health department officials mailed questionnaires to 3,600 people in Ota Ward, Chohu and Akiruno cities (all within greater Tokyo), with a response rate of 58%. Tokyo government Environmental Health workers visited the 2,078 respondents in person. In March 1997, the Tokyo health department chose the respondents suspected of having the allergy to cedar pollen and recommended examinations and tests to determine whether the subjects had the antibody in their blood.

Results showed that 19.4% citizens were allergic to cedar pollen in 1996. People aged 30 to 44 had the highest incident of the allergy. More than 30% of this age group in each of the three cities surveyed reported allergy problems.

The city of Akiruno, Tokyo, has five times more pollen in the air than the other two cities surveyed because of nearby forests, and 41.4% of its inhabitants aged 30 to 44 have allergies, compared with 25.7% of all respondents in the city, according to the survey.

There were no reports of cedar pollen allergy in these areas until 1963, according to the government report. Environmental Health officials suspect that a sudden release of cedar pollen on wind currents caused a sudden increase in allergy symptoms. Large numbers of cedar trees planted in the 1950s in Tokyo and near its western side have started to mature and release pollen.

The Bureau of Public Health established a section of allergy specialists in 1982 to counteract the increase in allergy to cedar pollen in Tokyo that year. In March 1997, the allergy section examined survey respondents with suspicious symptoms for sensitivity to four allergens -- cedar pollen, two types of grasses and ticks. Among the 2,078 respondents to the questionnaire, 647 reported running noses, sneezing and clogged noses from February to June and from August to October. Physicians examined 162 of these possible allergy patients. The cedar and grass pollen counts were high during those months.

The allergy section is conducting studies to develop methods for a new system to establish the prevalence of allergies and to find ways to reduce allergy to cedar pollen, the Environmental Health Division reported.

by Sandra Katzman