Total National Emissions
of Carbon Monoxide, 1970–2006*
(million short tons)
| Source category | 1970 | 1980 | 1990 | 1995 | 2000 | 2006 | Percent of Total 2006 |
|---|---|---|---|---|---|---|---|
| Highway vehicles | 163.23 | 143.83 | 110.26 | 83.88 | 68.06 | 54.10 | 53.8% |
| Other off-highway | 11.37 | 16.69 | 21.45 | 23.88 | 24.18 | 23.93 | 23.8% |
| Transportation total | 175.01 | 160.98 | 132.17 | 108.25 | 92.74 | 78.03 | 77.6% |
| Stationary fuel combustion total | 4.63 | 7.30 | 5.51 | 5.93 | 4.79 | 5.17 | 5.1% |
| Industrial processes total | 9.84 | 6.95 | 4.77 | 4.61 | 2.63 | 2.39 | 2.4% |
| Waste disposal and recycling total | 7.06 | 2.90 | 1.67 | 1.19 | 1.85 | 1.67 | 1.7% |
| Miscellaneous total | 7.91 | 15.02 | 13.30 | 7.30 | 12.96 | 13.30 | 13.2% |
| Total of all sources | 204.45 | 193.15 | 157.42 | 127.27 | 114.97 | 100.56 | 100.0% |
Source: U.S. Environmental Protection Agency, National Emission Inventory Air Pollutant Emission Trends website www.epa.gov/ttn/chief/trends (Additional resources: www.epa.gov/oar/oaqps)
* The sums of subcategories may not equal total due to rounding.
