Historical trends in the mass and chemical species concentrations of coarse particulate matter in the Los Angeles Basin and relation to sources and air quality regulations

Figures & data

Table 1. Samping location, sampling time and frequency, sampling instrument and method, analytical method, and other background information of the seven studies analyzed

	1986, CARB	Chow et al., 1994	Kim et al., 2000a	Sardar et al., 2005	Polidori et al., 2009	Arhami et al., 2009	Cheung et al., 2011
Location	AQMD Los Angeles (DLA)	AQMD Los Angeles (DLA)	AQMD Los Angeles (DLA)	USC in Los Angeles			USC in Los Angeles
	AQMD Rubidoux (RUB)	AQMD Rubidoux (RUB)	AQMD Rubidoux (RUB)	UCR in Riverside	Riverside retirement home (RIV)	S3in Long Beach	AQMD Van Buren (VBR)
	AQMD Long Beach (NLB)	Long Beach City College (LBCC)					AQMD Long Beach (HUD)
Sampling period	Jan–Dec 1986	11 days in Jun–Sep, 6 days in Nov–Dec in 1987	Jan 1995–Feb 1996	USC: Oct 2002–Sep 2003; UCR: Mar–Jun 2001	Aug–Oct 2006, Jan–Feb 2007	Mar–May 2007	Apr 2008–Mar 2009
Sampling time	Once every 6th day, daily samples	Sequential samples for each episode (5 in summer, 3 in winter)	Once every 3rd or 6th day, daily samples	Once every week, daily samples	7 weekly samples	6 weekly samples	Once every week, daily samples on Wednesday
Filter type	PTFE and quartz	Teflon and quartz	Teflon and quartz	Teflon and aluminum	Zefluor	Zefluor and quartz	Zefluor and quart
Sampling method	PM10: 16.7 lpm through a PM10 inlet, 5.6 lpm through each filter	PM10: 110 lpm through a PM10 inlet, 30 lpm through each filter	PM10: 97 lpm through a PM10 inlet, 10 lpm through each filterPM2.2	Micro-Orifice Uniform Deposition Impactor (MOUDI) operated at 30 lpm; Partisol sampler with PM10 and PM2.5 inlets operated at 16.7 lpm	Personal Cascade Impactor Sampler (PCIS) operated at 9 lpm with a PM10 inlet	PCIS operated at 9 lpm with a PM10 inlet	USC Virtual Impactor (VI) operated at a total flow of 50 lpm and a minor flow of 2 lpm with a PM10 inlet; PCIS operated at 9 lpm with a PM10 inlet
	PM2.2: 24.8 lpm to a cuclone separator with a cut point of 2.2 μm; 3–4.6 lpm through each filter	PM2.5: 110 lpm to a cyclone separator with a cut point of 2.5 μm; 35 lpm through each filter	PM2.5: 112 lpm to a cyclone separator with a cut point of 2.5 μm; 20 lpm through each filter
Analytic method (For elements, ions, and carboneous contents)	X-ray fluorescence	X-ray fluorescence	X-ray fluorescence	X-ray fluorescence	ICP-MS	ICP-MS	ICP-MS
	Ion chromatography.	Ion chromatography. Automated colorimetry, atomic absorption	Ion chromatography	Ion chromatography	NA	Ion chromatography	Ion chromatography
	Thermal desorption/ optical transmission	Thermal manganese oxidation	Optical thermal carbon analyzer	Thermal disorption/ optical transmission	Thermal disorption/ optical transmission	NA	Thermal disorption/ optical transmission
CPM calculation	Indirect, difference between PM10 and PM2.5	Indirect, difference between PM10 and PM2.5	Indirect, difference between PM10 and PM2.5	Direct	Direct	Direct	Direct
Statistics	Average	Average	Average	Average	Average	NA, composites	Average

Figure 1. Map of the samplings sites in downtown Los Angeles (DLA and USC), Long Beach (NLB, HUD, LBCC, and S3), and Riverside (RUB, VBR, UCR, and RIV). Sites operated and maintained by the SCAQMD are represented in triangles.

Figure 2. Annual concentrations of (a) PM₁₀ from 1988 to 2009 and (b) CPM/PM_2.5 from 1999 to 2009 in downtown Los Angeles.

Figure 3. Annual concentrations of (a) PM₁₀ from 1988 to 2009 and (b) CPM/PM_2.5 from 1999 to 2009 in Long Beach.

Figure 4. Annual concentrations of (a) PM₁₀ from 1988 to 2009 and (b) CPM/PM_2.5 from 1999 to 2009 in Riverside.

Figure 5. CPM concentrations of (a) mass, organic, and elemental carbon, and inorganic ions; (b) elements of crustal origins; and (c) elements of anthropogenic origins in downtown Los Angeles. Error bars show standard errors of the average when available.

Figure 6. CPM concentrations of (a) mass, organic and elemental carbon, and inorganic ions; (b) elements of crustal origins; and (c) elements of anthropogenic origins in Long Beach. Error bars show standard errors of the average when available.

Figure 7. CPM concentrations of (a) mass, organic and elemental carbon, and inorganic ions; (b) elements of crustal origins; and (c) elements of anthropogenic origins in Riverside. Error bars show standard errors of the average when available.

Table 2. Selected meteorological parameters from 1994 to 2009 in (a) downtown Los Angeles, (b) Long Beach, and (c) Riverside

	Temperature		Relative Humidity		Dominant Wind
	Avg. (°C)	SD	Avg. (%)	SD	Direction (%)	Speed (mps)
(a) Downtown Los Angeles
1994	17.5	5.7	53.0	16.1	NA
1995	17.7	5.1	57.1	15.9	W (19.2%)	2.6
1996	18.0	5.3	55.3	15.8	W (19.2%)	2.8
1997	NA		46.3	13.4	W (16.3%)	2.9
1998	NA		NA		NA
1999	17.3	5.3	51.4	15.2	W (21.0%)	3.0
2000	18.1	5.4	51.0	16.2	NA
2001	17.7	6.3	64.9	17.7	W (23.0%)	2.8
2002	17.8	6.0	60.3	18.8	NE (21.2), W (21.2%)	1.9 / 2.8
2003	16.4	5.3	59.0	20.1	NA
2004	18.3	5.9	60.9	18.9	S (19.4%), W (19.1%)	2.5 / 3.6
2005	18.2	5.5	53.8	25.7	NE (20.2%)	2.3
2006	18.4	6.3	61.7	18.6	NA
2007	18.1	6.3	60.5	19.3	W (22.0%)	2.7
2008	18.5	6.5	60.2	19.4	W (23.4%)	2.7
2009	18.4	6.2	59.3	18.8	W (27.9%)	3.1
	Temperature		Relative Humidity		Dominant Wind
	Avg. (°C)	SD	Avg. (%)	SD	Direction (%)	Speed (mps)
(b) Long Beach
1994	17.1	4.9	52.0	13	NA
1995	17.1	4.3	58.3	14	W (23.4%)	2.1
1996	16.0	5.7	45.1	20	W (22.4%)	2.2
1997	NA		69.1	22	W (20.9%)	2.0
1998	17.7	5.1	68.5	27	NA
1999	16.8	4.9	59.8	27	W (27.8%)	2.0
2000	17.6	4.9	72.5	21	NA
2001	16.8	4.8	72.5	17	W (24.9%)	1.8
2002	17.1	4.7	70.6	18	W (21.9%)	1.8
2003	17.8	4.9	64.2	29	W (20.7%)	1.8
2004	17.4	4.9	70.2	22	W (26.2%)	2.2
2005	17.5	4.6	71.4	24	W (29.2%)	2.3
2006	17.7	5.4	70.2	24	NA
2007	17.3	5.2	67.8	25	W (30.5%)	2.3
2008	17.7	5.5	69.1	25	W (31.5%)	2.2
2009	17.1	5.2	68.6	25	W (28.7%)	2.3
	Temperature		Relative Humidity		Dominant Wind
	Avg. (°C)	SD	Avg. (%)	SD	Direction (%)	Speed (mps)
(c) Riverside
1994	17.7	7.3	48.9	18	NA
1995	18.1	7.1	48.2	17	W (22.7%)	1.7
1996	18.4	7.2	48.4	19	W (26.4%)	1.9
1997	NA		69.1	22	NA
1998	19.9	8.1	NA		NA
1999	18.1	7.6	44.3	30	NW (24.1%)	2.3
2000	18.7	7.5	60.8	26	NA
2001	18.3	7.8	64.3	25	W (30.6%)	2.5
2002	18.3	7.4	63.4	27	W (27.2%)	2.4
2003	18.9	7.8	61.1	28	W (24.5%)	2.3
2004	18.7	7.4	60.0	25	NW (22.4%)	2.3
2005	18.8	7.0	67.8	27	NW (25.5%)	2.2
2006	19.1	7.9	63.6	28	NA
2007	19.0	7.8	61.6	28	NW (26.4%)	2.3
2008	19.5	8.1	62.2	27	NW (26.8%)	2.3
2009	19.1	7.7	59.6	27	W (24.0%)	2.4

Table 3. Linear regression analysis of PM data (PM₁₀ from 1988 to 2009, PM_10-2.5 and PM_2.5 from 1999 to 2009) in (a) downtown Los Angeles, (b) Long Beach, and (c) Riverside

		Linear Regression	R ^2	P
(a) Downtown Los Angeles
PM10	99th percentile	y = −3.71 (±0.39) x + 136 (±5.2)	0.82	<0.001
	98th percentile	y = −3.21 (±0.36) x + 124 (±4.8)	0.80	<0.001
	50th percentile	y = −1.19 (±0.12) x + 54.0 (±1.6)	0.83	<0.001
	Average	y = −1.33 (±0.12) x + 57.4 (±1.6)	0.86	<0.001
PM10-2.5	99th percentile	y = −0.02 (±1.1) x + 37.5 (±7.1)	0.00	0.98
	98th percentile	y = −0.42 (±0.82) x + 36.4 (±5.6)	0.03	0.62
	50th percentile	y = −0.54 (±0.23) x + 19.5 (±1.6)	0.37	0.05
	Average	y = −0.39 (±0.23) x + 18.9 (±1.5)	0.25	0.11
PM2.5	Average	y = −0.92 (±0.09) x + 24.6 (±0.64)	0.91	<0.001
		Linear Regression	R ^2	P
(b) Long Beach
PM10	99th percentile	y = −2.60 (±0.64) x + 110 (±8.1)	0.46	<0.001
	98th percentile	y = −2.46 (±0.60) x + 103 (±7.5)	0.47	<0.001
	50th percentile	y = −0.62 (±0.11) x + 40.5 (±1.3)	0.64	<0.001
	Average	y = −0.76 (±0.11) x + 44.8 (±1.4)	0.72	<0.001
PM10-2.5	99th percentile	y = −0.50 (±0.69) x + 41.0 (±4.7)	0.06	0.48
	98th percentile	y = −0.59 (±0.30) x + 34.9 (±2.0)	0.31	0.08
	50th percentile	y = −0.37 (±0.14) x + 17.1 (±0.96)	0.43	0.03
	Average	y = −0.22 (±0.11) x + 17.0 (±0.74)	0.31	0.07
PM2.5	Average	y = −0.87 (±0.09) x + 22.4 (±0.61)	0.91	<0.001
		Linear Regression	R ^2	P
(c) Riverside
PM10	99th percentile	y = −5.38 (±0.85) x + 207 (±11)	0.67	<0.001
	98th percentile	y = −4.72 (±0.77) x + 189 (±10)	0.65	<0.001
	50th percentile	y = −1.59 (±0.21) x + 82.2 (±2.8)	0.74	<0.001
	Average	y = −1.76 (±0.23) x + 84.6 (±3.0)	0.75	<0.001
PM10-2.5	99th percentile	y = −2.36 (±1.1) x + 93.8 (±7.7)	0.32	0.07
	98th percentile	y = −1.77 (±0.98) x + 84.2 (±6.7)	0.27	0.11
	50th percentile	y = −0.56 (±0.37) x + 35.2 (±2.5)	0.21	0.16
	Average	y = −0.57 (±0.29) x + 35.7 (±2.0)	0.30	0.08
PM2.5	Average	y = −1.69 (±0.12) x + 33.5 (±0.84)	0.96	<0.001
Notes: Values in parentheses represent standard errors of the slope and intercept.

Figure 8. Crustal enrichment factors in (a) downtown Los Angeles, (b) Long Beach, and (c) Riverside.

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