. 2014 Jul 29;13:61. doi: 10.1186/1476-069X-13-61

Table 3.

Spearman correlation coefficients between exposure variables (daily lag0) in Gothenburg, Sweden during the entire year, warm and cold periods (1 January 1985–31 December 2010)

Entire year	Temp	PM₁₀	PM_ion	PM_rest	SO₄²⁻	Total NO₃⁻¹	Total NH₄⁺	PM_2.5	Soot
Rel. hum	−0.331	−0.127	0.217	−0.272	0.208	0.280	0.134	0.115	0.235
	8859^a	7445	8139	7089	8622	8255	8311	1778	8588
Temp		0.003^b	0.130	−0.033	0.082	0.115	0.179	−0.026	−298
		7482	8473	7115	9097	8619	8667	1778^b	9038
PM₁₀			0.459	0.803	0.346	0.321	0.338	0.567	0.284
			7123	7123	7281	7212	7247	1773	7268
PM_ion				−0.059	0.877	0.833	0.862	0.615	0.535
				7123	8597	8597	8597	1744	8411
PM_rest					−0.111	−0.144	−0.129	0.289	0.022^b
					7123	7123	7123	1739	6976
SO₄²⁻						0.625	0.770	0.613	0.569
						8677	8724	1749	9025
Total NO₃⁻¹							0.761	0.500	0.377
							8669	1747	8509
Total NH₄⁺								0.586	0.540
								1747	8564
PM_2.5									0.479
									1752
Warm period	Temp	PM₁₀	PM_ion	PM_rest	SO₄²⁻	Total NO₃⁻¹	Total NH₄⁺	PM_2.5	Soot
Rel. hum	−0.161	−0.157	0.169	−0.306	0.189	0.219	0.104	0.005^b	0.019^b
	4454	3781	4139	3648	4342	4206	4214	913	4305
Temp		0.109	0.148	0.088	0.167	0.090	0.135	0.191	−0.057
		3781	4290	3648	4589	4372	4384	913	4546
PM₁₀			0.547	0.805	0.423	0.405	0.471	0.620	0.339
			3652	3652	3692	3694	3697	911	3673
PM_ion				0.033	0.887	0.857	0.871	0.697	0.502
				3652	4325	4325	4325	896	4219
PM_rest					−0.030^b	−0.059	0.012	0.323	0.124
					3652	3652	3652	894	3568
SO₄²⁻						0.665	0.788	0.657	0.548
						4362	4374	899	4514
Total NO₃⁻¹							0.745	0.611	0.325
							4373	898	4271
Total NH₄⁺								0.696	0.551
								897	4286
PM_2.5									0.424
									895
Cold period	Temp	PM₁₀	PM_ion	PM_rest	SO₄²⁻	Total NO₃⁻¹	Total NH₄⁺	PM_2.5	Soot
Rel. hum	0.183	−0.170	0.325	−0.332	0.239	0.410	0.298	0.142	0.158
	4405^a	3664	4000	3441	4280	4049	4097	865	4283
Temp		0.054	0.215	−0.068	0.138	0.262	0.140	0.011^b	−0.120
		3701	4183	3467	4508	4247	4283	865	4492
Warm period	Temp	PM₁₀	PM_ion	PM_rest	SO₄²⁻	Total NO₃⁻¹	Total NH₄⁺	PM_2.5	Soot
PM₁₀			0.381	0.801	0.275	0.248	0.239	0.516	0.238
			3471	3471	3589	3518	3550	862	3595
PM_ion				−0.140	0.869	0.815	0.864	0.567	0.630
				3471	4272	4272	4272	848	4192
PM_rest					−0.187	−0.218	−0.240	0.251	−0.084
					3471	3471	3471	845	3408
SO₄²⁻						0.592	0.769	0.581	0.644
						4315	4350	850	4511
Total NO₃⁻¹							0.784	0.429	0.458
							4296	849	4238
Total NH₄⁺								0.564	0.664
								850	4278
PM_2.5									0.518
									857

^aNumber of days less than 9496 in the entire year, 4758 in the warm and 4738 in the cold period due to missing exposure data.

^bp-value ≥ 0.05, otherwise p-value > 0.05.

Warm period: April − September, cold period: October − March.

PM₁₀ and PM_rest available from 1990–2010 and PM_2.5 available from 2006–2010.