Tab. 4.

Urea and creatinine levels in exposed workers vs controls

Parameter	Exposed	Unexposed	Reference range	P-value of unpaired t-test at 0.05 level of significance
Urea	15 ± 3.7	12 ± 3.8	7-23 mg/dL	<0.0001****
Creatinine	1.1 ± 0.18	0.93 ± 0.15	0.7-1.5 mg/dL	<0.0001****

This table summarizes the results of the renal tests. Mean urea and creatinine levels were significantly higher (unpaired t-test at 0.05 -level of significance) in the study group vs control group. These serum biochemical markers indicated nephropathy even though the values obtained did not exceed the reference level in any of the parameters studied.