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

Table 6: Comparison of U-Al concentrations in the exposed group between subjects without and with symptoms.

Respiratory chronic symptoms	U-Al concentrations (µg/l) in the exposed group (Mean ± SD)		p-Value^*
Respiratory chronic symptoms	Without symptoms	With symptoms	p-Value^*
Asthma	96.98 ± 7.64	96.98 ± 7.64	0.073
Chronic cough	95.03 ± 5.64	102.48 ± 8.62	0.001^***
Morning cough with sputum	97.19 ± 7.87	99.48 ± 7.43	0.282
Phlegm	97.86 ± 7.71	97.65 ± 9.72	0.957
Chronic phlegm	97.98 ± 7.90	96.23 ± 6.15	0.630
Wheeze	97.42 ± 7.60	100.95 ± 8.74	0.231
Respiratory problems (asthma, coughing) caused by current work	97.01 ± 7.33	104.90 ± 8.26	0.01^**

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