Temporal Analysis of PM₁₀ in Metropolitan Monterrey, México

Figures & data

Figure 1. Localization of MMA, México.

Figure 2. “Sistema Integral de Monitoreo Ambiental” network (Integrated Environmental Monitoring System).

Table 1. Descriptive statistics of PM₁₀ during 2006 –2008 (μg/m³)

Zone	Minimum	Maximum	Mean	SD
NE	56.17	116.30	81.47	14.61
CE	54.84	101.66	75.56	10.61
NW	68.60	135.62	91.89	17.15
SE	43.09	90.84	64.79	11.87
SW	66.83	158.90	106.42	22.74
Average	61.42	112.32	83.74	14.01

Figure 3. Monthly time series of PM₁₀ during 2006–2008 in five zones.

Figure 4. Frequency distribution of PM₁₀ in the (a) SE, (b) NE, (c) CE, (d) NW, and (e) SW zones.

Table 2. Descriptive statistics of PM₁₀ by season during 2006–2008 (μg/m³)

Season	Zone	n	Minimum	Maximum	Mean	SD
Spring	NE	277	17.88	201.83	78.98	24.00
	CE	267	14.29	162.63	75.84	25.39
	NW	259	12.21	185.48	86.19	27.76
	SE	239	14.62	149.96	66.66	22.56
	SW	275	17.10	227.08	98.12	34.43
Summer	NE	277	23.46	118.13	68.22	17.18
	CE	271	21.21	132.83	68.20	21.76
	NW	276	25.08	144.42	77.34	19.17
	SE	268	17.00	114.58	58.10	20.74
	SW	198	28.63	188.79	81.68	24.88
Autumn	NE	240	24.42	212.61	85.29	36.13
	CE	233	21.58	183.71	77.42	29.49
	NW	238	21.46	267.00	101.05	46.23
	SE	221	12.07	134.71	63.21	24.02
	SW	238	24.58	292.25	116.01	52.91
Winter	NE	263	15.58	319.58	94.24	43.22
	CE	265	13.25	247.61	81.29	35.21
	NW	264	13.36	318.68	103.99	45.98
	SE	246	11.58	241.00	69.44	31.79
	SW	260	21.08	294.09	123.39	52.56

Figure 5. Seasonal variation of PM₁₀ in (a) 2006, (b) 2007, and (c) 2008.

Figure 6. Day of the week variation of PM₁₀ in (a) 2006, (b) 2007, and (c) 2008.

Figure 7. Diurnal variation of PM₁₀.

Table 3. Pearson correlation coefficients between PM₁₀ and meteorological variables

Zone	Test	Wind Speed	RH	Temperature
SE	Pearson correlation	−0.007	−0.303^b	0.186^b
	Significance (two-tailed)	0.838	0.000	0.000
	N	955	955	955
NE	Pearson correlation	−0.177^b	−0.428^b	0.077^a
	Significance (two-tailed)	0.000	0.000	0.014
	N	1035	1039	1039
CE	Pearson correlation	−0.272^b	−0.178^b	0.149^b
	Significance (two-tailed)	0.000	0.000	0.000
	N	1019	1019	1019
NW	Pearson correlation	−0.191^b	−0.423^b	0.065^a
	Significance (two-tailed)	0.000	0.000	0.039
	N	1023	1022	1021
SW	Pearson correlation	−0.438^b	−0.422^b	−0.023
	Significance (two-tailed)	0.000	0.000	0.467
	n	1000	1000	1000
Notes: ^a P < 0.05; ^b P < 0.01.

Figure 8. Wind roses by season during 2008 in the SW zone for (a) winter, (b) spring, (c) summer, and (d) autumn.