Risk assessment of exposure to acrylamide using human biomonitoring studies: a complementary tool to environmental monitoring

Nowadays, we are exposed to thousands of chemicals in our daily lifes by many pathways of exposure, for example, by ingestion of food and water, inhalation of air and dust, dermal contact with personal care products, etc. In terms of public health, environmental monitoring is normally used to control the exposure of the population to these substances by the analysis of environmental samples. However, this approach does not give a complete scene of human exposure to chemicals, since the presence of these compounds in one environmental compartment does not reflect the real and complete uptake by the human body. This is because it does not consider all possible sources of exposure. By contrast, human biomonitoring (HBM) studies, which aim to analyze these compounds, their metabolites or reaction products in human biological samples (urine, blood, milk, etc.), can give a more accurate overview of human exposure to chemicals, since it captures the exposure to them by all potential sources. For this reason, it is widely claimed that environmental monitoring should be complemented with HBM studies in order to perform more accurate risk assessments and policy-making in public health.    

... environmental monitoring should be complemented with HBM [human biomonitoring] studies in order to perform more accurate risk assessments and policy-making in public health.

The principal objectives of HBM studies/programs are:    
- to obtain internal exposure levels to pollutants of the population;  
- to derive reference values of exposure biomarkers in different population groups to be able to compare among them, or to identify time trends;  
- to identify potential determinants of exposure by using questionnaire data;  
- to estimate the internal risk assessment;  
- to evaluate/complement official control programs (environmental monitoring) in terms of effectiveness;  
- to guide recommendations to reduce risks associated to the exposure to harmful pollutants.    

These studies/programs aim to generate HBM data for a wide variety of chemicals which are representative of their populations to control environmental exposure over time. Currently, a reduced number of countries among the world have currently long-term regular HBM programs at national level. In America, the U.S. National Health and Nutrition Examination Survey (NHANES), which is the first HBM program of the world, is normally performed every 2 years. In Canada, the Canadian Health Measures Survey (CHMS) was launched in 2007, comprising not only HBM data but also indoor air and tap water analysis. In addition, Asia, Korea and Japan have national HBM programs focusing on adults and children, respectively. In Europe, only six countries have well-implemented national HBM programs: Germany, Czech Republic, Sweden, Belgium, Slovenia and France. In the European Union, several projects have been performed so far in order to coordinate, encourage and harmonize HBM studies along Europe, such as the COPHES/DEMOCOPHES (Consortium to Perform Human Biomonitoring on a European Scale/Demonstration of a Study to Coordinate and Perform Human biomonitoring on a European Scale), the Human Biomonitoring for Europe (HBM4EU) initiative and the upcoming PARC (European Partnership for the Assessment of Risk from Chemicals).    

As it has been mentioned before, the conventional way of evaluating the