CORRELATION OF THE RATIO OF NON-METHANE HYDROCARBON AND NITROGEN OXIDES CONCENTRATION IN THE ATMOSPHERE AND OUTDOOR ENVIRONMENT

The correlation of atmospheric pollution by VOC and NMHC/NOX ratio has been found. By usingNMHC/NOX ratio, the source of NMHC in the region can be presumed without effects from the diffusionand the dilution by the meteorological conditions. At general measurement station in A city OsakaPrefecture, the NMHC/NOX ratio shows high value in summer though NMHC and NOX concentrationshow high value in early winter. As opposed to city A, traffic measurement station C doesnt show thispattern. It suggests that the amount of the exhaust of NMHC increases along with the temperature. Thewaste plastic processing facility was able to become a non-combustion system source in city A . Bycomparing the transition annual NMHC/NOX ratio at measurement station A and B, the waste plasticprocessing facility resulted to increase NMHC/NOX ratio. Ventilation is not useful for the improvement ofindoor air quality when outdoor pollution level is higher than indoors. Therefore, the NMHC/NOX ratiocan show the amount of the NMHC generation of non-combustion origin without receiving the influenceof meteorological conditions. NMHC/NOX ratio is a useful index to evaluate the change in the regionalenvironment by the VOC? pollution. This ratio of outdoor air can be adapted to ventilation control.