Frequently asked questions
- What is PM2.5 ?
- A fine substance with a diameter of 2.5μm or smaller.
PM2.5 is included in tobacco smoke, exhaust gas,
photochemical smog, soot which is generated
in the combustion (such as a stove), etc.
- What density level is dangerous to our health?
- The current guideline provides the following guide calling for caution.・Level１：Daily average under70μg/㎥‐No restrictions on activities.・Level２：Daily average 70μg/㎥ plus‐People should refrain from going outside.People should not engage in rigorous exercise.(“Interim guideline of warnings”of the Bureau of Environment of Japan website.)
- What kind of health effects is expected?
- PM2.5 particles are extremely small particles that can penetrate deep into the lungs,
causing respiratory diseases such as asthma and bronchitis as well as increasing
the risk of lung cancer and circulatory diseases.