Table 2. Specific gravity adjusted concentrations (ng/ml) of conjugated pyrene metabolites in cattle urine from urban and rural sites.

Site		n	PyG	PyS	PydiolS (M2)	PydiolS (M3)
Urban	GMSG ± SD	17	3.52 ± 2.99a)	0.589 ± 0.514a)	0.793 ± 1.52a)	2.55 ± 2.63a)
Rural	GMSG ± SD	78	4.24 ± 4.67a)	0.395 ± 0.409a)	1.36 ± 1.71a)	3.24 ± 3.01a)

n: number of samples; GM_SG: geometric mean concentration adjusted by specific gravity; SD: standard deviation; different letters (a and b) within a column indicate significant differences (Student’s t-test; P˂0.05).