Biomonitoring Human Exposure to Organohalogenated Substances by Measuring Urinary Chlorophenols Using a High-Throughput Screening (HTS) Immunochemical Method

9 pages, 5 tables, 3 figures.The widespread contamination of the environment by persistent organochlorinated substances is well-known. High-throughput immunochemical methods may improve routine assessment of the exposure of the population to these chemicals by analyzing urinary biomarkers. Trichlorophenols (TCP) have often been considered as biomarkers of many organochlorinated compounds. With the aim to assess exposure of the population to these substances a high-throughput immunosorbent solid-phase extraction (HTS-IS-SPE) procedure coupled to ELISA for simultaneous analyses of 2,4,6-TCP immunoreactivity equivalents (2,4,6-TCP-IR equiv) in multiple hydrolyzed urine samples has been developed. Around 100 urine samples can be processed simultaneously with an inter- and intra-assay precision lower than 23% CV and a limit of detection of 0.3 μg L-1.The analyses by HTS-IS-SPE−ELISA and HTS-IS-SPE−GC/MS of urine samples (N = 117) collected from three different population groups point to a broad exposure of the Catalonian population to organohalogenated substances including the recently emerging organobrominated pollutants. Environment and edible products seem to be the most likely sources of exposure, since excretion of 2,4,6-TCP-IR equiv has been found to be independent from the occupational sector. An excellent correlation was observed between the 2,4,6-TCP-IR equiv determined by HTS-IS-SPE−ELISA and the concentrations measured by HTS-IS-SPE−GC/MS (R2 = 0.912). The results show that immunochemical screening methods, based on the quantification of urinary biomarkers, can be excellent tools for exposure assessment. The HTS-IS-SPE−ELISA presented here has proved to be efficient, precise, accurate, rapid, and specific, which opens up the possibility for a broad variety of applications where routine testing of large number of samples is required.This work has been supported by MCyT (AGL 2002-04653-C04-03 and AGL2004-20341-E) and by EC (NM2-CT-2003-505485). M.N. thanks the Spanish Ministry of Education for her fellowship of the FPU program. We gratefully acknowledge Xavier Guardino, Jordi Obiols, and Enric Gadea (Instituto de Seguridad y Higiene en el Trabajo, Ministerio de Trabajo y Asuntos Sociales) as well as Angels Valbuena and Ana Oliete (Centre de Seguretat i Condicions de Salut en el Treball, Departament de Treball, Generalitat de Catalunya) for the helpful discussions and for kindly providing us with urine samples used on the evaluation/validation studies. The AMR group is a Grup de Recerca de la Generalitat de Catalunya and has support from the Departament d'Universitats, Recerca i Societat de la Informació de la Generalitat de Catalunya (expedient 2005SGR 00207).Peer reviewe