Japan's environment ministry says the pollen season has started early this year.

The allergy season usually starts in February, but this year airborne cedar pollen was observed in Tokyo on January 8, the earliest date on record.

An environment ministry survey found that nationwide the number of male cedar flower buds, which produce the pollen, slightly exceeds the average recorded in the last 10 years.

The figure was especially high in the western Kinki region. It was 5.6 times the average in Kyoto, and nearly 5 times that of Osaka's average.

The ministry also forecasts higher-than-usual levels of airborne particles, which can cause people who are allergic to suffer itchy eyes, sneezing and congestion.

Saito Hiroshi is a Senior Researcher at the Kanagawa Prefectural Natural Environment Conservation Center. He says" With high pollen dispersion, many people newly develop an allergy, while those who are already allergic may suffer heavier symptoms."

The expert warns that even those who have never experienced hay fever symptoms may feel irritation this year.

Saito calls on people to take precautions now as there are drugs that are more effective when you start taking them early.

One Tokyo drug store set up its anti-pollen products section two weeks earlier than usual.