Quality assurance and quality control for human biomonitoring data-focus on matrix reference materials

Human biomonitoring (HBM) is an essential tool for making evidence-based policy decisions upon assessment of human exposure to pollutants. In contrast, the heterogeneity of data reliability across studies has been identified as a weakness in current HBM research. The scientific community is currently encountering measurement challenges due to gaps in the availability of quality assurance/quality control (QA/QC) tools. This article provides a summarised view on the availability of reference materials in human matrices such as hair, serum, blood, plasma, urine, and breast milk for selected groups of organic contaminants (e.g., pesticides, flame retardants, perfluorinated compounds, perchlorate, phthalates, phenols) and elements (e.g., mercury, arsenic, cadmium, chromium, lead, nickel, tin) of relevance to human health. The QA/QC situation of HBM measurement data with regard to laboratories' performance in proficiency testing schemes is also addressed, highlighting areas for improvement. Finally, the article uses the example of per- and polyfluoroalkyl substance analysis to illustrate QA/QC challenges specifically related to the HBM field.