Table 3.

Factor loadings determined in the PCA analysis with Varimax rotation of trace elements and SIA measured at rural background EMEP site in Diabla Góra during January–March 2009 and January–March 2010

PM10 component	January–March 2009			January–March 2010
	PC1	PC2	PC3	PC1	PC2	PC3
As (ng m−3)	0.92	0.24	0.21	0.82	0.37	0.05
Cd (ng m−3)	0.93	0.17	0.12	0.86	0.09	0.37
Cr (ng m−3)	0.30	0.05	0.92	0.44	0.27	0.62
Cu (ng m−3)	0.04	0.72	0.63	0.30	0.30	0.75
Ni (ng m−3)	0.65	0.63	0.13	0.53	0.68	0.09
Pb (ng m−3)	0.84	0.41	0.26	0.91	0.28	0.21
Zn (ng m−3)	0.71	0.53	0.32	0.91	0.20	0.27
SO4 2− (μg(S) m−3)	0.53	0.73	0.13	0.49	0.32	0.52
NH3 + NH4 + (μg(N) m−3)	0.35	0.89	0.01	0.31	0.85	0.17
HNO3 + NO3 − (μg(N) m−3)	0.63	0.44	0.30	0.11	0.91	0.25
% Variance	42.4	29.6	15.8	39.7	25.5	15.7
PM source	LPS	Remote sources	Residential/traffic	LPS	Remote sources	Residential/traffic

Factor loadings >0.6 are represented in italics