Since the second quarter of 2002, Motor Vehicle Emission Research Laboratory (under the National Institute of Environmental Research) conducted a study on five domestic oil refineries and seven import oil refineries, for the sulfur and benzene content in diesel fuels and gasolines. The following are the results for the fourth quarter (Oct.-Dec.) of 2002.

-For benzene content in gasolines, domestic oil refineries maintained 0.2~ 0.7% (0.4% in average), which was similar to that of the third quarter, and for the import refineries, the content increased at an average of 0.9%, maintaining a range of 0.6~1.4% (1.1% in average).

-Sulfur-content in gasolines for domestic oil refineries was significantly decreased (about 8%) from the third quarter, maintaining a range of 13~34 ppm (23ppm in average). Import refineries maintained 26~127ppm (83ppm in average), which was also a decrease (9%) from the third quarter.

-For sulfur content in diesel fuels, import oil refineries had a decrease of 25% from the third quarter, down to a range of 106-321ppm(average of 202ppm), whereas domestic refineries had a significant increase of 21% from the third quarter's average of 128 ppm, maintaining a range of 96~240ppm (155 ppm in average).

The analysis of the results revealed that, pollutants emitted by motor vehicles, such as hydrocarbon and nitric oxide were reduced to about 1%~4.4%. Also, benzene emitted by motor vehicles were reduced as much as 45%. The increase in sulfur content for domestic refineries for the fourth quarter can be contributed to the increase in the use of oil for heaters during the months of October to December.