Comprehensive Analysis of PM10 in Belgrade Urban Area on the Basis of Longterm Measurements

Comprehensive analysis of PM10 in Belgrade urban area on the basis of longterm measurements

Environmental Science and Pollution Research

a b c c,d e a a A. Stojić , S. Stanišić Stojić , I. Reljin , M. Čabarkapa , A. Šoštarić , M. Perišić and Z. Mijić a Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia b Faculty of Physical Chemistry, University of Belgrade, Studentski Trg 12-16, 11000 Belgrade, Serbia c Faculty of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11120 Belgrade, Serbia d Singidunum University, Danijelova 32, 11010 Belgrade, Serbia e Institute of Public Health Belgrade, Bulevar Despota Stefana 54, 11000 Belgrade, Serbia

*Corresponding author: [email protected]; Phone: +381 11 371 30 04; Fax: +381 11 316 21 90; Pregrevica 118, 11080 Belgrade.

Measurement methodology

The automatic measurements of inorganic gaseous pollutants (NOx, NO2, NO, SO2 and CO) were conducted in accordance with the standards: EN 14212:2012 for SO2 measurements by ultraviolet fluorescence; EN 14211:2012 for NO2 and NO measurements by chemiluminescence; EN 14626:2012 for CO measurements by non-dispersive infrared spectroscopy. Precision of these measurements was acquired through the type-approval testing. Accuracy was assured through daily zero/span checks by the use of calibration gases traceable to the reference material with expanded uncertainty less than 5% and through regular calibration performed by the reference material with expanded uncertainty less than 1%. Besides that, accuracy was confirmed through proficiency testing schemes organized by the WHO in collaboration with JRC, and according to the results, z-score amounted to less than 1 for all of the observed species and concentrations.

The semi-automatic measurements (automatic sampling followed by the manual sample preparation and quantification of the target compounds) of PM10, benzo[a]pyrene and trace metals (As, Cd, Ni and Pb) were conducted in accordance with the standard methods: EN 14902:2005 for determination of Pb, Cd, As and Ni in PM10 fraction; EN 12341:2014 for determination of PM10; EN 15549:2008 for benzo[a]pyrene. The semi-automatic - + 2+ 2+ + - 2- + measurements of the ions (Cl , Na , Mg , Ca , K , NO3 , SO4 and NH4 ), OC/EC, and soot were conducted in accordance with the in-house developed methods. Precision was achieved by repeated testing of the sample of known concentrations. The acceptance criteria for relative standard deviations were derived from the modified Horwitz equation (EC document SANCO/3030/99 rev. 4 11/07/00). Relative standard deviations (%) are shown in Table 2. Accuracy was assured by the usage of standard reference materials and inter-laboratory comparisons. According to the results, z-score amounted to less than 1 for all examined species and concentrations. Uncertainties for semi-automatic methods were calculated by adding contributions related to sampling procedure which included uncertainties of the calibration of sampling flow rate and calibration of temperature and pressure measurements.

The uncertainties, performance criteria and the obtained test results are listed in the Online Resource, Table 1 and 2.

1 Tables

Table 1. Precision, uncertainty and sources of error for NOx, NO2, NO, SO2 and CO measurements

Standard method EN 14626:2012 (CO) EN 14211:2012 (NO and EN 14212:2012 (SO2) NO2) Performance criterion ≤3.0 µmol mol-1 ≤ 3.0 nmol mol-1 ≤ 3.0 nmol mol-1 Test result 0.070 µmol mol-1 1.70 nmol mol-1 0.14 nmol mol-1 Uncertainty 11% 10% 11% Sources of error Standard uncertainty for: calibration gas; sample gas pressure and temperature variations; surrounding temperature variation; electrical voltage variation; the presence of water vapour and other interferents with positive and/or negative impact; and reproducibility under field conditions. Standard uncertainty for Standard uncertainty for Standard uncertainty for repeatability standard repeatability standard repeatability standard deviation at zero; at the 8- deviation at zero; at the deviation at zero; at the hour mean limit value; and level of the hourly limit annual limit value; and standard uncertainty for value; and standard standard uncertainty for lack of fit at the 8-hour uncertainty for lack of fit lack of fit at the annual mean limit value. at the level of the hourly limit value. Standard uncertainty for: limit value. Standard uncertainty for: averaging; difference Standard uncertainty for: averaging; difference sample/calibration port; long-term drift at zero and sample/calibration port; long-term drift at zero and at the level of the hourly long-term drift at zero and at level of the 8-hour mean limit value; converter at level of the annual limit limit value. efficiency; difference value. sample/calibration port;

the increase of NO2 concentration due to the residence time in the analyzer.

- + 2+ 2+ + - 2- + Table 2. Precision and uncertainties for Cl , Na , Mg , Ca , K , NO3 , SO4 , NH4 , OC/EC, soot, PM10, benzo[a]pyrene and trace metal measurements

Parameter Precision RSD [%] Expanded uncertainty Ca2+ 3.0 15% Na+ 3.1 6% K+ 3.1 7% + NH4 3.7 13% - NO3 2.8 7% 2- SO4 2.4 8% Cl- 3.0 9% Mg2+ 3.2 11% OC/EC 3.2 14% soot 3.6 8% As 1.3 7% Cd 0.7 7% Ni 2.3 12% Pb 0.6 8% Benzo[a]pyren 2.2 12% e -3 PM10 0.2 3.0 µg m

2 -3 Table 3. Basic statistics for daily and hourly PM10 concentrations [µg m ]

Year 24-h 1-h Average Min Max StdDev Average Min Max StdDev 2003 60.5 19. 272.2 43.9 2004 55.6 12.5 263.4 32.2 2005 47.3 8.98 420.9 40.5 2006 41.6 8.4 149.5 25.3 2007 47.2 11. 206.2 27.9 2008 38.2 6.80 179.5 27.8 2009 40.0 9.5 234.0 27.2 2010 30.0 6.7 150.7 21.3 2011 57.7 8.5 376.8 54.9 58.4 4.0 499. 64.1 2012 54.7 12. 281.4 41.0 55.0 4.1 490.3 52.4 2013 56.7 17.0 180.6 30.4 56.9 4.1 471.2 45.0 2014 60.3 12.6 281.2 36.4 62.4 4.2 499.3 59.2 2015 67.8 18.2 233.5 37.0 68.8 4.4 353.3 49.5 Tota 47.9 6.70 420.9 36.1 54.4 4.0 499.1 50.3 l 3

3 Table 4. The relative importance for all measured and GDAS1-obtained parameters obtained by the use of random forest

Paramete - + + - 2- r OC EC NOx NO2 NO SO2 CO soot PM10 As Cd Cl Cr K Mn Ni Pb NH4 NO3 SO4 BaP 12011. 2170. 62. 0. 31. 46. OC 8.5 12493.5 7503.0 2 1434.4 2.9 2 21501.6 6 4 7.8 5.3 10.5 0 6 549.5 195.4 571.3 850.2 350.9 13901. 0. 13. 11. EC 398.0 20741.8 1965.1 6 570.9 0.3 488.2 816.8 6.7 2 4.8 5.7 0.6 2 4 115.2 76.4 107.2 138.5 46.0 54259. 2198. 16. 0. 11. 26. 36.

NOx 435.9 8.8 12063.7 1 1145.1 1.7 0 4402.2 0 8 4.0 2 2.8 6 6 397.4 102.1 221.6 299.3 110.5 4274. 41. 0. 15. 36.

NO2 799.5 1.6 26674.4 2843.6 510.0 3.0 6 13461.8 2 3 6.2 7.0 5.8 4 7 266.7 190.4 577.2 745.2 188.2 3686. 0. 27. 32. NO 395.6 5.1 71722.8 2466.9 2302.8 1.1 9 2628.0 7.4 5 4.0 5.4 1.8 1 8 300.9 70.2 124.1 235.4 128.0 19914. 2117. 24. 0. 72. 55.

SO2 489.9 3.2 16336.6 5505.7 7 2.0 3 5629.1 6 3 8.4 9.8 2.4 3 9 163.0 98.9 129.0 238.4 122.3 19821. 6731. 92. 0. 40. 72. CO 1893.1 3.4 29255.3 16324.5 3 2212.7 7 17842.4 5 5 7.2 6.8 4.5 1 6 462.2 145.7 448.1 306.8 491.1 21319. 21. 0. 14. 36. 1420. soot 541.6 1.8 18605.4 9583.2 4 1021.0 2.8 11394.5 8 5 12.5 4.2 7.6 7 8 243.7 236.0 1189.9 9 194.9 4489. 90. 0. 36. 45. 2264.

PM10 2743.2 1.6 9930.4 10374.7 9655.2 1707.7 3.4 3 8 5 9.0 4.7 11.9 8 5 625.2 510.5 1055.1 2 394.1 3349. 0. 39. 91. As 1602.0 3.7 15067.4 9591.9 9125.9 1682.0 3.9 2 25260.8 6 9.3 9.1 4.5 6 1 848.6 281.2 557.8 648.2 400.9 26501. 3172. 45. 34. 36. Cd 897.9 3.5 36582.2 8678.2 1 794.2 2.5 2 13625.0 3 4.5 8.4 4.8 5 3 1765.2 292.1 405.3 803.6 232.7 1175. 0. 24. Cl- 153.7 1.4 7311.2 2219.7 4775.8 430.2 0.3 1 2667.2 7.1 1 7.9 5.7 7.1 7 127.6 204.0 586.4 907.9 18.0 0. 14. 18. Cr 95.1 1.0 5280.6 1217.3 2994.8 399.3 0.2 311.7 677.5 3.9 1 7.2 0.4 1 3 394.0 175.6 116.7 260.9 44.6 3791. 18. 0. 12. 16. 2088. K+ 881.2 1.8 7795.5 5460.8 5922.7 660.2 1.2 2 13783.8 6 2 16.0 4.3 0 4 200.6 617.9 1802.3 5 79.6 16138. 1191. 44. 0. 14. 60. Mn 711.3 3.3 16709.6 5762.5 0 3886.7 2.1 0 7636.1 9 4 5.5 5 1.9 1 227.2 106.2 166.1 499.0 277.9 10535. 1432. 49. 0. 34. Ni 744.7 3.4 14286.2 4342.4 7 1095.1 1.7 6 6067.5 3 2 7.9 6.9 0.8 5 217.9 137.0 139.2 204.8 169.6 1149. 45. 1. 25. 28. Pb 1018.1 1.4 11508.1 4158.9 5725.1 867.0 1.3 8 13858.1 4 4 4.2 6.2 2.5 5 0 210.0 341.6 678.3 167.8 1870. 0. 30. 3299. + NH4 385.7 1.7 2578.5 3501.9 3223.5 313.7 0.3 6 4349.6 7.7 2 10.1 6.7 8.2 4.2 0 209.5 1536.4 0 29.9 3756. 12. 0. 32. 2877. - NO3 446.9 1.5 3480.3 4579.2 2487.1 274.4 1.2 5 8614.2 7 1 23.0 5.3 12.4 6.7 3 217.0 725.3 0 41.5 2425. 0. 12. 1151. 2- SO4 427.9 1.0 3333.0 6987.7 2261.2 486.1 0.6 2 8975.1 9.6 1 14.6 4.9 9.1 6.2 5 218.8 1 1916.1 25.6 19382. 3671. 87. 0. 65. 58. BaP 1876.3 4.9 23937.0 10582.6 2 1737.4 3.4 2 16355.4 3 7 7.0 7.8 6.4 3 7 563.9 133.2 344.4 301.2 22612. 1313. 0. 16. 18. ws 235.8 1.6 60323.9 5813.2 7 489.2 0.9 5 2700.3 8.1 2 3.4 8.0 1.9 1 2 158.1 397.1 113.2 124.0 59.4 12162. 0. 22. wd 188.4 2.5 11010.8 1199.3 8 323.0 0.2 355.1 1222.3 3.8 2 5.2 3 0.6 6.8 7.7 256.3 58.6 94.9 157.1 20.4 12. 0. 13. T 305.8 3.4 5576.3 1107.6 2870.9 710.1 0.5 584.8 1534.2 3 1 6.2 7.1 1.4 9.9 9 110.4 164.1 389.1 455.3 49.6 0. 12. 11. Rh 117.6 1.0 2948.5 2562.9 2401.3 574.9 0.2 445.2 581.0 2.7 1 4.2 3.9 0.6 0 9 79.0 88.8 78.4 233.7 54.6 0. P 228.8 1.4 4362.0 1189.4 2516.9 247.6 0.2 435.9 1666.3 4.5 1 8.2 6.1 3.1 4.1 9.3 138.8 227.9 315.0 601.5 30.5 0. 22. ws10m 137.6 1.8 3962.8 1136.2 2586.3 167.7 0.1 631.8 1168.5 4.5 1 3.8 3.1 1.1 6.4 6 91.4 643.9 243.7 971.2 21.1 0. prss 173.4 1.6 3173.4 1014.4 2493.0 206.4 0.1 451.3 863.9 4.5 1 5.8 4.4 1.1 4.5 9.4 126.8 164.2 179.1 252.5 25.4 0. mslp 196.2 1.3 3343.5 995.8 2476.5 192.1 0.2 511.9 1252.7 4.5 1 7.3 5.0 1.8 5.2 6.4 104.4 162.6 179.3 324.0 24.2 0. umof 87.8 1.6 2486.9 758.2 2327.1 216.1 0.2 405.5 631.3 3.6 1 5.3 7.3 0.5 5.4 7.4 203.4 60.6 38.5 189.3 12.4 vmof 107.0 1.5 6022.5 1124.9 2836.6 301.6 0.2 263.6 343.4 3.3 0. 5.2 6.6 0.8 4.9 32. 120.8 64.2 92.8 133.7 27.2

4 1 7 0. 30. shif 106.0 4.1 5192.7 2714.6 2525.8 474.1 0.3 542.8 525.5 4.9 1 8.5 8.3 1.2 9.2 6 122.7 163.1 122.7 277.5 25.3 0. 23. dswf 223.7 3.3 8567.3 2396.5 4970.3 316.9 0.7 813.8 588.7 5.7 1 5.8 4.6 1.2 5.7 1 101.8 102.4 97.5 271.2 18.7 0. 13. rh2m 80.9 1.3 2758.7 1381.5 3039.1 429.8 0.2 441.9 448.2 2.4 2 5.2 4.5 1.0 4.6 1 160.1 41.3 90.2 188.8 17.7 17. 0. 18. t02m 288.2 3.0 5580.7 1238.8 5065.2 700.8 0.6 809.1 1911.5 2 1 8.3 6.3 1.8 9.4 0 83.3 162.3 387.8 279.6 45.3 0. 12. tcld 136.0 2.5 1773.9 913.4 2744.1 494.8 0.1 417.5 435.0 3.1 1 3.3 3.2 1.4 5.6 6 127.5 55.9 61.8 135.6 23.1 0. cape 103.5 1.2 3332.9 701.6 1830.4 373.7 0.2 180.4 1147.1 5.6 0 1.6 5.3 0.4 2.5 4.0 71.1 117.8 60.9 57.7 15.2 10. 0. cinh 90.1 0.9 2125.9 571.6 2548.7 394.6 0.3 235.4 892.9 2 1 1.7 4.1 0.6 2.4 7.0 88.1 153.6 117.5 108.7 20.4 26. 0. 13. 1280. lisd 929.9 1.9 4223.7 1505.5 3748.0 809.5 0.8 709.6 7008.4 4 1 8.4 8.5 3.6 8.1 5 157.6 300.1 631.0 5 71.5 10. 0. 10. lib4 239.1 2.3 4349.5 1295.5 3432.3 431.7 0.4 409.3 3088.9 5 1 10.0 2 2.7 7.9 6.8 140.3 293.7 841.5 534.2 45.1 1391. 15. 0. 24. 58. pblh 716.9 2.1 13399.1 3958.7 7557.3 377.0 1.9 5 3738.6 3 1 5.1 5.6 1.6 5 0 121.3 167.5 131.5 284.8 186.3 21. 0. 13. tmps 368.4 2.8 5885.9 1493.0 4788.0 755.9 0.6 739.4 2062.0 5 1 11.9 7.0 1.2 8.8 9 110.3 130.9 315.8 262.5 69.5 0. solm 131.8 0.9 5386.6 1430.8 6859.4 446.2 0.2 565.4 344.8 3.8 1 2.5 7.9 0.9 4.7 5.8 81.7 59.0 87.8 212.8 7.9 0. crai 10.1 0.9 677.7 249.3 681.7 44.9 0.0 43.7 96.5 0.4 0 0.4 2.2 0.1 0.8 0.7 6.6 10.8 4.7 12.0 0.9 0. 2044. lcld 160.4 1.4 2568.5 1182.7 3453.5 179.5 0.2 463.9 734.3 2.5 1 5.6 3.3 1.5 4.4 7.7 198.9 236.8 270.6 2 11.5 10593. 1517. 21. 0. 26. lhtf 564.4 1.7 9699.3 2577.6 3 730.2 0.9 0 1758.5 5 1 8.5 7.7 1.8 7.4 0 103.4 115.1 192.3 366.9 233.2 0. 14. mcld 130.6 3.4 1824.4 748.5 2036.5 232.3 0.1 348.4 583.9 2.8 1 3.1 2.1 0.9 5.3 9 88.9 75.6 33.5 139.0 22.5 0. 12. hcld 180.7 4.4 1971.3 1564.7 2821.7 397.4 0.1 310.4 369.9 2.5 0 3.4 3.8 0.6 6.9 0 89.8 94.0 48.3 167.0 36.0

Table 5. GDAS parameter abbreviations

Parameter Unit Abbreviat Pressure at surface hPa PRSSion Pressure reduced to mean sea level hPa MSLP Accumulated precipitation (6 h accumulation) m TPP6 u-component of momentum flux (3- or 6-h average) N m-2 UMOF v-component of momentum flux (3- or 6-h average) N m-2 VMOF Sensible heat net flux at surface (3- or 6-h average) W m-2 SHTF Downward short wave radiation flux (3- or 6-h average) W m-2 DSWF Relative Humidity at 2m AGL % RH2M Wind direction ° WD10M Wind speed m/s WS10M Temperature at 2m AGL K TO2M Total cloud cover (3- or 6-h average) % TCLD Geopotential height gpm* SHGT Convective available potential energy J kg-1 CAPE Convective inhibition J kg-1 CINH Standard lifted index K LISD Best 4-layer lifted index K LIB4 Planetary boundary layer height m PBLH

5 Temperature at surface K TMPS Accumulated convective precipitation (6 h accumulation) m CPP6 Volumetric soil moisture content frac. SOLM Categorial snow (yes=1, no=0) (3- or 6-h average) CSNO Categorial ice (yes=1, no=0) (3- or 6-h average) CICE Categorial freezing rain (yes=1, no=0) (3- or 6-h average) CFZR Categorial rain (yes=1, no=0) (3- or 6-h average) CRAI Latent heat net flux at surface (3- or 6-h average) W m-2 LHTF Low cloud cover (3- or 6-h average) % LCLD Middle cloud cover (3- or 6-h average) % MCLD High cloud cover (3- or 6-h average) % HCLD

Table 6. Number of samples and total, seasonal (Au, Sp, Su and Wi) and heating/non-heating period (H, NH) basic -3 - + 2+ + + - 2- statistics for CO [mg m ], PM10, OC, EC, NOx, NO2, NO, SO2, soot, Cl , Na , Ca , K , NH4 , NO3 and SO4 [µg m3], and As, Cd, Cr, Mn, Ni, Pb and BaP [ng m-3] (2011-2014)

Paramete No Average Min Max r Au Sp Su Wi H NH Total Au Sp Su Wi H NH Total Au Sp Su Wi H NH Total

PM10 25 96.8 36.8 38. 69.5 85.2 39. 62.2 23.4 15.2 14.7 14.0 14.0 14.7 14.0 376. 86.5 130. 175. 376. 130. 376.8 OC 194 23.5 6.1 5.99 13.2 18.4 6.12 12.2 5.1 3.5 3.9 5.3 3.6 3.5 3.5 83.78 11.3 13.61 29.96 83.78 13.61 83.7 EC 194 4.0 3.1 2.8 3.8 3.8 3.0 3.4 2.2 1.3 1.6 2.0 1.8 1.3 1.3 8.5 7.0 6.0 6.3 8.5 7.0 8.5 4 NOx 25 174. 95.1 78. 117. 153. 85. 119. 47.2 1.6 1.6 18.0 18.0 1.6 1.6 463. 252. 299. 301. 463. 299. 463.6 3 4 4 2 6 2 3 6 5 4 4 6 4 NO2 25 84.5 57.1 53. 53.4 75.1 52. 63.8 25.6 4.6 4.6 11.7 11.7 4.6 4.6 244. 118. 161. 122. 244. 161. 244.8 NO 254 105. 41.7 31.0 73.9 93.1 37.6 65.0 9.4 2.8 2.8 6.8 6.8 2.8 2.8 273.8 138.2 94.56 243.5 273.8 244.6 273.7 3 8 9 1 7 1 1 7 6 SO2 25 28.4 9.9 9.9 24.3 25.8 10. 18.4 7.1 2.9 2.6 3.7 3.7 2.6 2.6 96.1 25.6 40.7 55.6 96.1 74.8 96.1 CO 253 1.3 0.6 0.5 1.1 1.2 0.69 0.9 0.4 0.2 0.1 0.5 0.3 0.1 0.1 3.7 1.2 1.2 2.4 3.7 1.6 3.7 soot 254 35.2 19.1 17. 35.7 34.7 19. 26.9 4.9 2.4 4.1 11.4 4.1 2.4 2.4 174. 47.8 40.0 70.1 174. 47.8 174.0 As 254 3.6 0.8 0.66 3.1 3.4 0.70 2.1 0.2 0.1 0.1 0.6 0.2 0.1 0.1 14.90 2.7 2.7 7.7 14.90 3.2 14.9 Ca2+ 834 15.3 8.1 8.6 7.4 11.8 9.2 10.4 3.9 3.4 3.7 3.9 3.6 3.4 3.4 24.9 17.3 19.5 11.7 24.9 19.5 24.9 Cd 25 0.3 0.1 0.1 0.3 0.3 0.1 0.2

6 Ni 25 5.9 3.5 3.0 5.7 5.8 3.3 4.5 1.4 0.8 0.5 2.0 0.7 0.5 0.5 16.8 12.1 12.0 28.7 28.7 12.1 28.7 Pb 254 11.8 5.5 4.5 10.2 11.1 5.0 8.1 1.4 1.5 1.6 3.4 1.9 1.4 1.4 49.2 17.0 13.5 65.3 65.3 17.0 65.3 + 4 NH4 24 11.0 2.6 2.6 5.9 8.4 3.1 5.7 0.2 0.3 0.2 0.9 0.2 0.2 0.2 58.7 13.3 12.1 18.9 44.7 58.7 58.7 - 2 NO3 24 18.6 6.4 5.2 13.5 17.0 5.4 11.1 1.2 0.5 1.4 3.8 3.8 0.5 0.5 80.1 18.9 12.1 40.7 80.1 14.3 80.1 2- 2 SO4 24 22.7 11.0 10. 13.3 18.6 11. 14.8 1.4 3.4 4.4 3.9 1.4 3.1 1.4 92.7 38.1 40.1 31.4 92.7 40.1 92.7 BaP 252 5.9 0.3 0.39 3.7 5.1 0.32 2.7 0.0 0.1 0.1 1.0 0.3 0.0 0.0 52.1 1.8 1.5 12.2 52.1 1.6 52.1 DL4 – detection limit

Table 7. Unmix-derived absolute PM10 source profiles and solution stability obtained using bootstrap method [ng m3] Soil Fuel Bootstrap Industrial Bootstrap Secondary Bootstrap Particle Bootstrap Species Burning Percentiles Emission Percentiles Aerosols Percentiles Resuspension Percentiles 25th 75th 25th 75th 25th 75th 25th 75th OC 5.87 4.58 6.81 1.87 0.97 2.96 1.09 1.04 1.88 2.98 2.49 3.85 EC 0.58 0.38 0.75 0.40 0.10 0.40 0.31 0.25 0.52 1.86 1.77 2.36 NOx 22.89 10.12 29.94 28.58 17.58 29.51 0 0 0 72.05 71.64 89.79 NO2 10.05 3.50 13.27 9.35 2.94 9.61 8.28 6.63 12.37 36.93 36.93 48.83 NO 17.61 4.38 25.49 19.04 13.32 23.02 0 0 0 34.06 30.84 43.46 SO2 6.00 4.30 6.62 3.26 2.29 4.25 1.93 1.74 3.02 7.57 5.86 10.16 CO 0.33 0.24 0.37 0.09 0.03 0.10 0.11 0.10 0.16 0.37 0.36 0.47 Soot 7.81 5.37 8.53 4.52 2.72 5.61 5.54 4.08 7.63 9.67 9.16 12.50 As 1.42 1.19 1.62 0.32 0.21 0.49 0.13 0.12 0.32 0.24 0.15 0.32 Cd 0.01 0.01 0.03 0.17 0.15 0.19 0.01 0.01 0.02 0 0 0 Pb 0.89 0.16 1.81 5.04 4.12 5.81 1.27 1.19 1.82 0.39 0.09 0.93 Cl 0.47 0.20 0.55 0.08 0 0.15 0.74 0.69 1.04 1.10 1.01 1.35 NH4 0.54 0 0.64 1.05 0.45 0.94 4.41 4.36 5.73 0 0 0 NO3 3.11 2.12 3.32 0.94 0.14 0.98 5.68 5.41 7.82 1.72 1.35 2.15 SO4 1.80 0.84 2.45 2.45 1.30 2.17 7.27 7.07 9.31 2.43 1.90 2.88 BaP 2.51 2.15 2.77 0 0 0 0.06 0 0.23 0 0 0

Figures

7 Fig. 1 Lomb-Scargle periodogram of hourly pollutant concentrations

Fig. 2 Seasonal diurnal variations of PM10 concentrations (2011-2015)

8 Fig. 3 PM10 polar cluster variability (above) and monthly and weekly variations (below)

-3 Fig. 4 Polar weekly variations of PM10 concentrations [μg m ]

9 Fig. 5 Inverse multifractal spectrum

Fig. 6 PM10-chemical composition (left) and annual mean concentrations of inorganic gaseous pollutants and soot (right)

10 Fig. 7 Seasonal variability of local production, background and transport contributions obtained by TSA

Fig. 8 TCA-resolved cluster seasonal variability

11 Fig. 9 Seasonal variability of potential emission sources resolved by CWT [µg m-3]