Industrial processes
			Petro-			Storage	Waste
	Chemical	Metals	leum	Other	Solvent	and	disposal	Total
	indus-	pro-	indus-	indus-	utili-	trans-	and	indus-
Year	tries	cessing	tries	tries	zation	port	recycling	trial
	million tons
1940	0.006	0.004	0.105	0.107	na	na	0.110	0.332
1950	0.063	0.110	0.110	0.093	na	na	0.215	0.591
1960	0.110	0.110	0.220	0.131	na	na	0.331	0.902
1970	0.271	0.077	0.240	0.187	na	na	0.440	1.215
1980	0.213	0.065	0.072	0.205	na	na	0.111	0.669
1989	0.273	0.083	0.097	0.311	0.003	0.002	0.084	0.852
1990	0.168	0.097	0.153	0.378	0.001	0.003	0.091	0.892
1991	0.165	0.076	0.121	0.352	0.002	0.006	0.095	0.816
1992	0.163	0.081	0.148	0.361	0.003	0.005	0.096	0.857
1993	0.155	0.083	0.123	0.370	0.003	0.005	0.123	0.861
1994	0.160	0.091	0.117	0.389	0.003	0.005	0.114	0.878
1995	0.158	0.098	0.110	0.399	0.003	0.006	0.099	0.873
1996	0.146	0.083	0.134	0.386	0.002	0.007	0.095	0.854
1997	0.149	0.088	0.138	0.404	0.002	0.007	0.096	0.884
1998	0.152	0.088	0.138	0.408	0.002	0.007	0.097	0.893
	Fuel combustion					Non-		Total
	Electric	Indus-			On-road	road	Miscel-	all
Year	utilities	trial	Other	Total	vehicles	sources	laneous	sources
	million tons
1940	0.660	2.543	0.529	3.732	1.330	0.991	0.990	7.374
1950	1.316	3.192	0.647	5.155	2.143	1.538	0.665	10.093
1960	2.536	4.075	0.760	7.371	3.982	1.443	0.441	14.140
1970	4.900	4.325	0.836	10.061	7.390	2.182	0.330	21.179
1980	7.024	3.555	0.741	11.318	8.621	4.011	0.248	24.866
1989	6.593	3.209	0.736	10.537	7.682	4.528	0.293	23.893
1990	6.663	3.035	1.196	10.895	7.089	4.804	0.369	24.049
1991	6.519	2.979	1.281	10.779	7.469	4.900	0.286	24.249
1992	6.504	3.071	1.353	10.928	7.622	4.934	0.255	24.596
1993	6.651	3.151	1.308	11.111	7.806	4.942	0.241	24.961
1994	6.565	3.147	1.303	11.015	8.075	5.015	0.390	25.372
1995	6.384	3.144	1.298	10.827	7.826	5.128	0.267	24.921
1996	6.057	3.072	1.224	10.354	7.848	5.167	0.452	24.676
1997	6.191	3.019	1.193	10.403	7.875	5.251	0.411	24.824
1998	6.103	2.969	1.117	10.189	7.765	5.280	0.328	24.454

Source:  U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, National Air Quality and Emissions Trends Report, 1998, Table A-4 (EPA, OAQPS, Research Triangle Park, NC, 2000), and earlier reports in this series.

Notes:  na = not available. Non-road sources include non-road gasoline engines, non-road diesel (e.g., construction and farm), aircraft, marine vessels, and railroads. Miscellaneous is not defined by the Source.

Last Updated on Tuesday, May 2, 2000