Human biomonitoring (HBM) can be defined as "a method for assessing human exposure to chemicals (or their associated effects) by measuring these chemicals, their metabolites, or reaction products in human tissues or specimens such as blood, urine or hair'.  

Role of HBM in integrated assessment

In many cases, HBM data has proved to be a valuable supplement to, or have even surpassed, estimates of exposure based on environmental measures. HBM directly measures the amount of a chemical substance in a person’s body, taking into account often poorly understood processes such as bioaccumulation, excretion, metabolism and the aggregate uptake variability through different exposure pathways.  The data can therefore make a number of important contributions to integrated assessments:

1. They can provide more direct estimates of exposures to environmental contaminants than extrapolations from chemical concentrations in soil, air or water;
2. They can help to quantify and understand the (otherwise hidden) links between exposure, internal dose and health reponse (see Figure 1);
3. In this way, they can provide information on variations in, and help to identify determinants of, susceptibility in human populations.   

Figure 1.  The role of human biomonitoring in understansing exposure-dose-response relationships

Over the last decade or so, a wide variety of human biomarkers have been developed and tested.  These provide the capability to assess exposures to, and health effects from, a range of different chemicals.  Details of 15 biomarkers, representing some of the most common (classes of) chemicals are provided in the Toolkit section of this Toolbox (see links via Table 2, below).   Further details are also available from the report, Biomarker review and development strategy, which can be downloaded below.

Table 2.  Links to information for biomarkers of key chemicals

Biomarkers such as these have a number of specific characteristics that give them advantages over other sources of data:  

• Biomarkers represent aggregate exposure and, if chosen wisely, can help to interpret and anlayse environmental health impacts of exposure mixtures;
• Biomarkers describe a continuum between exposure and health effects, and thus provide linked and consistent information on exposure-health relationships (Smolders et al. 2010b);
• New developments in related sciences, generally referred to as the “-omics” technologies, are creating novel opportunities for the discovery of new relationships between exposure and health effects;
• Biomarker data and PBPK models support one another, either by providing mechanistic understanding of the dose-metric, or by model validation of PBPK models (see PBPK modeling).

Sources of HBM data 

With the growing recognition of the value of HBM data, a number of large population surveys have been initiated in recent years, both in Europe and more widely (Table 1).  These can give a good idea of the typical levels of chemicals that are observed in the general population.  In addition, many smaller, ad hoc studies have been undertaken, often focused on specific chemicals and population groups.  As the example of surveys relating to blood-lead in the EU (see link below) indicates, however,  combining data from these can face difficulties, because of differences in survey design and analytical methodology.  Further information is also given in the Biomarkers inventory, which can be downloaded below.

Table 1. A brief overview of some large scale HBM population surveys.

File Attachments: 

Biomarker review and development strategy.pdf