Chapter 2F. The Flemish Environment and Health Study (FLEHS)– Second Survey (2007–2011): Establishing Reference Values for Biomarkers of Exposure in the Flemish Population

The second Flemish human biomonitoring survey (2007–2011) generated information on the distribution of biomarker values for a large number of environmental pollutants in a representative sample of the Flemish population. The study was implemented by the Flemish Centre of Expertise for Environment and Health, which was funded and steered by the Flemish government. From May 2008 to July 2009, 255 newborns and their mothers, 210 adolescents (14–15 years old) and 204 adults (20–40 years old) were recruited as a representative sample of the Flemish population. In all age groups, invitation letters, information brochures, letter of informed consent and self-administered questionnaires were distributed. The collected samples consisted of cord blood from the newborns, blood from the mothers, the adolescents and the adults, urine from the adolescents and the adults, and hair from the mothers. In addition to historical compounds (i.e. heavy metals, persistent chlorinated compounds, 1-hydroxy pyrene and t,t-muconic acid), new emerging pollutants were analyzed for the first time in individual samples from the Flemish population. Perfluorinated compounds and polycyclic musk compounds could be detected in all analyzed blood samples. Levels of brominated flame retardants were under the limit of quantification in most individual blood samples. Bisphenol A, metabolites of phthalates and para-hydroxybenzoic acid, a metabolite of parabens, could be detected in 90% or more of the urine samples. For metabolites of organophosphate pesticides, the highest detection frequency was observed for DMTP, detected in 90–95% of the individual urine samples. In addition, 2,5-DCP, a metabolite of para-dichlorobenzene, could be detected in over 80% of the individual urine samples. Margins of safety (MOS) were calculated by dividing the P90 obtained in FLEHSII by the available health based biomonitoring equivalants (BEs). MOS below 10 were found for toxicologically relevant arsenic, cadmium, lead, MeHg, HCB and phthalates.