Composition and sources of fine and coarse particles collected during 2002–2010 in Boston, MA

Figures & data

Figure 1. Relative contributions of coarse and fine particles to total PM₁₀ mass.

Figure 2. Mass closure results for (a) fine and (b) coarse particles.

Table 1. Source contributions to fine particle mass and elemental concentrations (ng/m³) at Harvard Supersite

	Regional pollution	Motor vehicles	Sea salt	Crustal/road dust	Oil combustion	Wood burning	Estimated	Measured	%MRE
BC	105	350	1	3	81	43	583	658	12
Na	69	0	18	5	30	21	174	195	11
Al	9	7	0	29	1	1	47	47	1
Si	3	12	0	52	0	0	67	67	0
S	729	151	2	10	66	12	971	980	1
Cl	0	1	14	0	0	0	15	15	2
K	6	0	1	7	0	23	37	37	0
Ca	1	9	1	13	4	1	28	29	3
Ti	0	1	0	1	0	0	3	3	0
V	0	0	0	0	3	0	3	3	1
Fe	0	37	0	17	6	0	61	61	1
Ni	0	0	0	0	2	0	2	3	2
Cu	0	2	0	1	0	1	3	4	8
Zn	0	5	0	0	2	3	10	11	9
Pb	1	1	0	1	1	1	5	5	9
PM2.5	4,220	1,836	48	383	663	1,648	8,798	9,353	6

Table 2. Source contributions to coarse particle mass and elemental concentrations (ng/m³) at Harvard Supersite

	Crustal/road dust	Motor vehicles	Sea salt	Estimated	Measured	%MRE
Na	21	17	99	137	155	12
Al	98	14	5	117	115	2
Si	235	40	0	275	273	1
Cl	3	9	245	258	263	2
K	38	8	5	51	52	1
Ca	24	101	0	125	125	0
Ti	9	3	0	12	12	0
Mn	2	1	0	4	4	12
Fe	143	56	4	203	211	4
Cu	2	2	0	3	3	6
Zn	2	2	0	4	5	10
Br	1	1	0	2	3	21
Ba	11	9	1	21	27	21
PM2.5–10	2,782	981	732	4,495	5,049	11

Figure 3. Annual average concentrations and standard deviations of (a) fine and (b) coarse particles.

Figure 4. Seasonal average concentrations of (a) fine and (b) coarse particles.