Comparison of S-Al concentrations in the exposed group between subjects without and with symptoms.

Table 5: Comparison of S-Al concentrations in the exposed group between subjects without and with symptoms.

Respiratory chronic symptoms	S-Al concentrations (µg/l) in the exposed group (Mean ± SD)		p-Value^*
Respiratory chronic symptoms	Without symptoms	With symptoms	p-Value^*
Asthma	5.30 ± 1.48	6.15 ± 1.36	0.044^*
Chronic cough	5.05 ± 1.41	6.24 ± 1.31	0.001^***
Morning cough with sputum	5.33 ± 1.51	5.93 ± 1.37	0.137
Phlegm	5.48 ± 1.50	5.85 ± 1.24	0.633
Chronic phlegm	5.55 ± 1.50	4.98 ± 1.24	0.415
Wheeze	5.45 ± 1.47	5.87 ± 1.80	0.465
Respiratory problems (asthma, coughing) caused by current work	5.32 ± 1.46	7.06 ± 0.29	0.003^**

T-test: ^*significant at P < 0.05, ^**significant at P < 0.01, ^***significant at P < 0.001.