Table 3.

Random forest ranking of exposure components for each respiratory function outcome. Relative importance ranking of each measured component in predicting differences between exposed and control animals.

	F	Ti	Te	Tv	Mv	PIF	PEF	EF50	PAU	EIP	EEP	Penh
Mass	18	17	16	16	6	15	6	4	4	5	10	3
PN	16	18	10	9	9	12	5	7	6	4	2	5
Total SO4	13	11	5	12	12	20	15	11	2	6	14	2
Acidic SO4	1	1	1	13	14	18	8	12	22	7	16	20
Neutralized SO4	11	12	6	10	7	13	9	8	11	8	4	11
NH4	14	13	4	7	8	10	3	6	10	9	6	6
OC	8	7	17	11	11	8	20	18	13	17	7	16
EC	10	10	9	2	1	1	1	1	9	13	20	14
TC	7	6	12	14	2	2	12	2	14	15	8	13
Al	2	4	2	18	21	19	17	19	16	2	9	18
Si	6	5	11	23	17	17	21	21	20	23	18	21
Fe	3	2	14	8	20	6	19	15	3	16	12	12
Ni	9	9	18	5	22	11	14	13	8	18	13	8
Zn	20	20	22	3	16	16	16	16	19	11	17	9
Pb	21	21	19	22	18	22	2	22	23	21	23	22
Mg	19	19	20	6	19	4	11	10	18	1	21	19
Na	23	23	21	1	5	3	13	17	17	3	5	15
O3	15	8	7	4	3	5	2	3	12	12	1	4
NO	4	15	3	15	10	9	18	20	5	22	22	7
NO2	12	16	13	20	4	7	4	5	1	14	11	1
NO3	17	22	15	19	15	14	10	14	15	20	15	17
SO2	22	14	23	21	23	23	23	23	21	19	19	23
Pinene	5	3	8	17	13	21	7	9	7	10	3	10