Table 6.

Spearman’s coefficient of rank correlation for individual level association between biomarker concentrations and exposure metrics.

	PM2.5 (µg/m3)	Fe (ng/m3)	Mn (ng/m3)	Cr (ng/m3)	Fe (as a % of PM2.5 by mass)
Urinary, raw
Isoprostanes (nmol/L)	−0.17	−0.17	−0.18	−0.27	−0.01
8-oxodG (nmol/L)	−0.06	−0.13	−0.20	−0.23	−0.19
BPDE (pmol/mL)	−0.19	−0.10	−0.14	−0.20	0.30
Mn in urine (µg/L)	−0.18	−0.18	−0.21	−0.25	−0.01
Cr in urine (µg/L)	−0.02	−0.10	−0.12	−0.12	−0.23
Pb in urine (µg/L)	−0.18	−0.24	−0.24	−0.32*	−0.18
Creatinine (mg/dL)	−0.19	−0.24	−0.29	−0.35*	−0.08
Urinary, creatinine-normalized
Isoprostanes/creatinine (nmol/mmol)	−0.12	−0.10	−0.09	−0.13	−0.03
8-oxodG/creatinine (nmol/mmol)	0.19	0.17	0.13	0.21	−0.14
BPDE/creatinine (nmol/mmol)	−0.14	−0.01	0.05	0.07	0.36*
Urinary Mn/creatinine (ng/mg)	−0.10	−0.05	0.01	0.06	−0.03
Urinary Cr/creatinine (ng/mg)	0.12	0.06	0.10	0.10	−0.15
Urinary Pb/creatinine (ng/mg)	0.12	0.10	0.17	0.16	−0.16
Plasma
Protein carbonyls (nmol carbonyl/mL plasma)	−0.08	−0.01	0.06	0.00	0.16
Mn in plasma (µg/L)	−0.14	−0.23	−0.22	−0.24	−0.37*
Cr in plasma (µg/L)	0.13	0.13	0.08	0.07	−0.19
Pb in plasma (µg/L)	0.06	− 0.04	0.03	0.04	−0.48**
Whole blood
DNA–protein crosslinks (%)	0.18	0.19	0.16	0.16	0.05
Mn in blood (µg/L)	0.13	0.18	0.21	0.13	0.22
Cr in blood (µg/L)	n/a	n/a	n/a	n/a	n/a
Pb in blood (µg/L)	0.16	0.11	0.17	0.12	− 0.12

n/a—chromium in blood results are not reported because concentrations were found to be inversely proportional to sample volume indicating that the sodium heparin anticoagulant may have contaminated the samples with detectable amounts of chromium.

Abbreviations: 8-oxodG, 8-oxodeoxyguanosine; BPDE, benzo(a)pyrene diol epoxide; Cr, chromium; DNA, deoxyribonucleic acid, isoprostanes, 15-F2t–isoprostane;Mn, manganese; Pb, lead.

Significant correlations between biomarkers and exposure metrics are indicated as follows.

^*p < 0.05

^**p < 0.01