Variability of Particle Number, Black Carbon, and PM₁₀, PM_2.5, and PM₁ Levels and Speciation: Influence of Road Traffic Emissions on Urban Air Quality

Figures & data

FIG. 1 Location of BCN-CSIC urban background monitoring site.

TABLE 1 Mean, minimum, and maximum hourly levels and % standard deviation for PM₁₀, PM_2.5, PM₁, N, BC, SO₂, NO, NO₂, O₃, CO, T, RH, Wind speed, boundary layer depth and traffic intensity measured in Barcelona during July–November 2007

	Mean	Min.	Max.	Std. dev. (%)
PM10 (μ g m^−3)	40	8	203	46
PM2.5 (μ g m^−3)	28	3	117	42
PM1 (μ g m^−3)	17	3	73	43
N (cm^−3)	24065	4865	93080	45
BC (μ g m^−3)	3.6	0.2	25.3	86
SO2 (μ g m^−3)	2	1.0	41.0	144
NO (μg m^−3)	17	1	587	223
NO2 (μ g m^−3)	39	1	279	64
O3 (μ g m^−3)	38	1	119	73
CO (mg m^−3)	0.4	0.2	4.1	74
T (°C)	20	5	34	25
RH (%)	68	17	100	20
Wind speed (m s^−1)	4.0	0.2	15	55
Boundary layer depth (m)	428	127	1040	38
Traffic intensity (Vehicles h^−1)	5274	210	14346	55

FIG. 2 Mean daily variation of temperature and relative humidity (a), wind speed and wind direction, (b) and solar radiation and boundary layer depth (c) calculated from hourly means for the period July–November 2007.

FIG. 3 Mean daily evolution of black carbon concentration (BC) and particle number concentration (N) at BCN-CSIC site and road traffic intensity/wind speed ratio evolution at Barcelona Diagonal Avenue on weekdays (a) and weekends (b) measured simultaneously during the period July–November 2007.

FIG. 4 Mean daily evolution of the N/BC ratio (10⁶/μg) calculated from hourly means for the period July–November 2007.

FIG. 5 Seasonal evolution of the daily variation of N and BC levels measured at BCN-CSIC site and the solar radiation evolution measured simultaneously during the period July–November 2007.

FIG. 6 Mean daily evolution of PM _{2.5 − 10}, PM_{1 − 2.5}, and PM₁ levels at BCN-CSIC site and road traffic intensity at Barcelona Diagonal Avenue on weekdays (a) and weekends (b) measured simultaneously during the period July–November 2007.

FIG. 7 Mean daily evolution of the levels of NO, NO₂, O₃, SO₂, and CO measured at L'Hospitalet-Gornal site in weekdays (a) and weekends (b) during the period July–November 2007.

FIG. 8 Mean annual levels of the major components (in μ g m⁻³) measured in PM_{2.5 − 10} (a), PM_{1 − 2.5} (b), and PM₁ (c) at BCN-CSIC (from 100 daily samples of each PM₁₀, PM_2.5, and PM₁ fractions measured simultaneously during the year 2007).

FIG. 9 PM_2.5/PM₁₀ (%, top of the bar) and PM₁/PM₁₀ (%, bottom of the bar) ratios calculated from mean annual levels of trace elements measured at BCN-CSIC (from 100 daily samples of each PM₁₀, PM_2.5, and PM₁ fractions measured simultaneously during the year 2007).

FIG. 10 Correlation of mean BC daily levels with the simultaneous total carbon (Ctotal), Ni, and Cu (a) and Fe, Sn, and Sb (b) daily levels measured in PM₁₀ at BCN-CSIC during the period July–November 2007.

FIG. 11 Evolution of mean annual levels of PM_{1 − 10} and PM₁ at BCN urban sites, vehicle fleet in Barcelona city and % diesel in Barcelona province from 1999 to 2007.

FIG. 12 Correlation between mean annual PM₁ levels and year of measurement (a), mean annual vehicle fleet (b) and % diesel in the fleet (c) in Barcelona from 1999 to 2006.