. Author manuscript; available in PMC: 2020 Jul 14.

Published in final edited form as: J Air Waste Manag Assoc. 2019 Jan 9;69(3):373–390. doi: 10.1080/10962247.2018.1537985

Table 4.

2011 CAMx-PSAT apportionment of U.S. anthropogenic and U.S. background (natural plus international) contributions to ammonium sulfate and ammonium nitrate concentrations.

CAMX PSAT 2011 annual average concentration, μg/m³
Class I national parks	Ammonium sulfate total	Ammonium sulfate: U.S. anthropogenic	Ammonium sulfate: U.S. background	Ammonium nitrate total	Ammonium nitrate: U.S. anthropogenic	Ammonium nitrate: U.S. background
Olympic	1.254	0.226	1.028	1.027	0.668	0.360
Glacier	0.780	0.133	0.648	0.468	0.234	0.234
Yellowstone	0.584	0.128	0.456	0.232	0.179	0.053
Mesa Verde	0.789	0.245	0.545	0.128	0.119	0.009
Grand Canyon	0.749	0.165	0.585	0.024	0.016	0.008
Joshua Tree	0.873	0.175	0.698	0.657	0.611	0.046