Considerations for Biological Monitoring and Biomarker Analysis

The use of biological markers in biomonitoring involves several considerations, such as the best specimen, time of collection, and chemical to measure.

Analytical considerations include specimen stability, contamination, and method validation. Urine and blood are the most suitable specimens for routine monitoring due to invasive sampling procedures, external contamination, and inconvenience in obtaining and analyzing other specimens.

The design of biomonitoring studies, including sampling, transportation, storage, and analytical procedures, should consider these specimen characteristics. The figure illustrates the main routes of exposure and the matrices available for analysis of biomarkers based on bioaccumulation and excretion patterns.

The choice of matrix for specific biomonitoring depends on the chemical of interest, its persistence, and deposition. The table shows different matrices and procedures in various stages of life for biomonitoring studies, including fetal development, delivery, and lactation. Understanding the principles for the use of biological markers is essential for the accurate and reliable interpretation of biomonitoring data and the assessment of environmental exposure.

Review questions:

• What are the main considerations for selecting the appropriate biological specimen for biomonitoring?
• How does the choice of matrix for biomonitoring depend on the persistence and deposition of the chemical of interest?
• What are the potential sources of contamination that should be considered when measuring low concentrations of a chemical in biological specimens?
• What are the advantages and disadvantages of measuring parent chemicals, metabolites, or adducts in biomonitoring studies?