• Biomarkers can exhibit effect of electron transfer or reception • Biomarkers are effective early warning signals of adverse biological effects. • Biomarkers can indicate biological effects, while chemistry-based surveillance system cannot. • Biomarkers are more effective in revealing overall toxicities of complex mixtures. • Biomarkers are economical. • Biomarker have different degrees of specificity.

Table 1: Main advantages of Biomarkers (modified after [28]).