Applicability of non-invasively collected matrices for human biomonitoring

The recent adoption of human biomonitoring (HBM) as Action 3 in the Environment and Health Action Plan 2004–2010 of the European Commission [1,2] has motivated the implementation and application of HBM in European environment and health research.One of the most important issues hampering the routine application of HBM on a large scale is the obvious need to collect human samples, often invasively. Blood has the undeniable advantage that it is in contact with all tissues and in equilibrium with organs and tissues. Therefore, it has been used extensively for various research and survey goals. However, blood sampling is an invasive procedure and suffers from ethical and practical constraints, particularly for small children or other susceptible populations [3,4]. The European Commission's SCALE Initiative (Science, Children, Awareness, EU Legislation and continuous Evaluation) has specifically identified children as a main target population for environment and health policies, so including this subpopulation in any HBM project is a priority [5]. Likewise, sampling non-invasively collected matrices is preferable in particularly vulnerable groups, such as pregnant women, elderly, or chronically-ill people.Additionally, repeated or even routine biomonitoring may be desirable for the efficiency evaluation of risk management options and efficacy of environment and health policies. For short-lived chemicals such as volatile organic compounds or agricultural pesticides, average exposures may not reflect peak exposures arising through infrequent exposure episodes. Repeated sampling of high-exposure subjects provides more insight into the true nature of these episodes and of their toxicological consequences [6,7].Finally, because non-invasively collected matrices need less specialized personnel for sampling, costs associated with large sampling designs may be significantly reduced [8,9].Because of these advantages, there is a strong case for non-invasively collected matrices fo