cost benefit analysis of co control strategies in seoul metropolitan area ies korea phase iii part 2 yeora chae yrchae kei re kr contents o research scope and tasks preliminary results future air pollution trends 0 000 005 010 015 020 025 030 035 040 045 050 055 1990 1991 1992 1993 1994 1995 1996 1997 199 8 1999 2000 2001 year ppm 10 20 30 40 50 60 70 80 90 m pm10 no so why quality problem is serious smpa too many people cars category unit national total incheon gyeonggi km 99 852 11 700 5 12 605 958 137 population thousand 48 289 22 525 47 331 582 9 612 density person 483 1 925 4times 17 062 634 948
