Human biomonitoring in risk assessment: analysis of the current practice and 1st examples HBM in risk assessments of HBM4EU priority chemicals

In chemicals risk assessment frameworks, the default approach is to assess external intake from different sources of exposure and via different routes of exposure. They are often assessed separately. This approach includes various uncertainties and often overestimates the real uptake since default, conservative estimates are used e.g. for the absorption of the chemical. At the same time, actual (real life) exposure may be underestimated by not taking into account that exposure to a chemical substance may occur from different sources, which may fall under separate legislative frameworks. Examples are triclosan that is used in biocidal products as well as in consumer products and importantly, most if not all chemicals that are produced by workers where at the same time these workers may be exposed as part of the general population. In some cases, other tools to assess exposure via all possible routes may be insufficient; an example is occupational exposure via hand-to-mount exposure, which has been shown to occur for example in the case of many metals, like lead, through contaminated hands. Without biomonitoring, exposure in these cases could become severely underestimated. Human Biomonitoring (HBM) is an important tool to survey the real life body burden – or internal exposure – of humans resulting from ‘total’ exposure to chemicals via different routes (lung, skin, digestive tract) and ‘via’ different legislative frameworks on chemicals. By providing more accurate data on actual body burdens (internal exposure), inclusion of HBM data could improve human health risk assessment for both the general population (exposure via air, consumer products, drinking water and food) as well as for workers (exposure via inhalation and/or skin) separately or as part of the population.