Table 2.

The log-transformed means, standard deviations, and ranges of total skin NKA level [ln(ng/μg keratin)] and urine biomarker levels [ln(μg/L)] as well as the associations between these biomarker levels and the specific genotypes in the fuel-cell maintenance workers exposed to jet fuel.

	Prevalence (%)	Total NKA	1-naphthol	2-naphthol	Total naphthols	Naphthalene	Total urine biomarkers*
Average		1.03	9.58	9.96	10.54	5.4	10.56
STD		0.38	1.19	1.17	1.13	2.21	1.14
Range		0.24–2.04	6.18–11.31	6.18–12.49	6.88–12.53	−0.84–10.59	6.89–12.53
Association:
CYP2E1*6
DD	88/105 (84)	1.04	9.55	9.94	10.52	5.29	10.55
CD	14/105 (13)	0.91	9.78	10.07	10.65	6.13	10.67
CC	3/105 (3)	1.18	9.63	10.03	10.54	5.26	10.56
GSTM1-null	63/105 (60)	1.03	9.52	9.94	10.5	5.13	10.52
GSTM1-plus (++/+−)	42/105 (40)	1.03	9.68	10	10.6	5.82	10.64
GSTT1-null	24/105 (23)	0.91a	9.81	9.99	10.64	5.88	10.65
GSTT1-plus (++/+−)	81/105 (77)	1.06	9.51	9.96	10.51	5.26	10.54
NQO1
CC	66/105 (63)	1.06	9.75	10.08	10.69	5.6	10.71
CT	34/105 (32)	1	9.25	9.75	10.26	4.87	10.28
TT	5/105 (5)	0.69b	9.68	9.97	10.56	6.43	10.578

^*The log-transformed sum of urine naphthalene, 1NAP, and 2NAP levels;

^aSignificant difference (p = 0.080) from the mean level in the GSTT1-plus group;

^bSignificant difference (p = 0.085) from the mean level in the NQO1 (CC) type.