Correlations between variables, with linear regression lines, Pearson’s r, and significance. (A) Cr-U versus Cr-EBC (r = 0.25, p < 0.05). (B) Cr-EBC versus H2O2-EBC (r = 0.54, p < 0.01). (C) Cr-EBC versus MDA-EBC (r = 0.59, p < 0.01). (D) H2O2-EBC versus MDA-EBC (r = 0.49, p < 0.01). (E) Cr-U versus H2O2 EBC (r = 0.41, p < 0.01). (F) Cr-U versus MDA-EBC (r = 0.19, not significant).