Photochemical Oxidants (Ox)

A type of pollutant produced by chemical reactions that occur between nitrogen oxide and organic compounds in the atmosphere due to the effect of UV rays from the sun. Not only does it cause photochemical smog, but it may also irritate mucosa at high concentrations and have negative effects on respiratory organs as well as on plants, including agricultural products.

Measuring unit: ppm

Photochemical Smog Advisory

Yamanashi prefecture announces photochemical smog alert when the level of photochemical oxidant exceeds 0.12ppm and such level is forecast to continue. There are four levels to the alerts declared by the prefecture according to the concentration level of the photochemical oxidant: 1. forecast, 2. advisory, 3. warning, and 4. emergency warning.

Sulfur Dioxide (SO2)

Sulfur dioxide is generated when sulfur-containing fuels such as petroleum and coal are oxidized through the process of combustion. Highly concentrated sulfur oxide may cause negative effects on respiratory organs, and it may also become the cause of acidic precipitation which has a negative impact on forests and lakes.

Measuring unit: ppm

Nitric oxide (NO)

Nitrogen Oxides refer to a compound of nitrogen and oxygen generated by chemical reactions including general combustion. They primarily take the form of nitrogen oxide (NO) or nitrogen dioxide (NO2) in the atmosphere, and they are produced from various sources including factories/industry, automobiles, and homes. The majority of the nitrogen oxides in the air is first emitted in the form of nitric oxide, and it later turns into nitrogen dioxide through the oxidization process in the atmosphere. Highly concentrated nitrogen dioxide may cause negative effects on respiratory organs, and it may also become the cause of acidic precipitation and photochemical oxidants.

Measuring unit: ppm

Nitrogen Dioxide (NO2)

Nitrogen Oxides refer to a compound of nitrogen and oxygen generated by chemical reactions including general combustion. They primarily take the form of nitrogen oxide (NO) or nitrogen dioxide (NO2) in the atmosphere, and they are produced from various sources including factories/industry, automobiles, and homes. The majority of the nitrogen oxides in the air is first emitted in the form of nitric oxide, and it later turns into nitrogen dioxide through the oxidization process in the atmosphere. Highly concentrated nitrogen dioxide may cause negative effects on respiratory organs, and it may also become the cause of acidic precipitation and photochemical oxidants.

Measuring unit: ppm

Nitrogen Oxides (NOx)

Nitrogen Oxides refer to a compound of nitrogen and oxygen generated by chemical reactions including general combustion. They primarily take the form of nitrogen oxide (NO) or nitrogen dioxide (NO2) in the atmosphere, and they are produced from various sources including factories/industry, automobiles, and homes. The majority of the nitrogen oxides in the air is first emitted in the form of nitric oxide, and it later turns into nitrogen dioxide through the oxidization process in the atmosphere. Highly concentrated nitrogen dioxide may cause negative effects on respiratory organs, and it may also become the cause of acidic precipitation and photochemical oxidants.

Measuring unit: ppm

Non-methane Hydrocarbon (NMHC)

Hydrocarbon is a collective term for the organic compounds of carbon and hydrogen. Non-methane hydrocarbon involved in photochemical reaction is used for evaluating the concentration of hydrocarbon in the atmosphere.

Measuring unit: ppmC

Methane (CH4)

Hydrocarbon is a collective term for the organic compounds of carbon and hydrogen. Non-methane hydrocarbon involved in photochemical reaction is used for evaluating the concentration of hydrocarbon in the atmosphere.

Measuring unit: ppmC

Total Hydrocarbons (THC)

Hydrocarbon is a collective term for the organic compounds of carbon and hydrogen. Non-methane hydrocarbon involved in photochemical reaction is used for evaluating the concentration of hydrocarbon in the atmosphere.

Measuring unit: ppmC