1,2-Dihydroxynaphthalene as biomarker for a naphthalene exposure in humans

ObjectivesThe possibly carcinogenic properties of naphthalene are, regarding to its ubiquitary presence, of environmental–medical and occupational–medical importance. Seven isomeric dihydroxynaphthalenes (DHN) were examined for their suitability as biomarkers in human biomonitoring and to get insights in human naphthalene metabolism.MethodsWe developed a GC–MS-method for the quantification of 1,2-, 1,4-, 1,5-, 1,6-, 1,7-, 2,6- and 2,7-DHN after solid phase extraction and derivatization with BSA/TMCS. The internal burden of DHN after exposure to naphthalene was determined by measuring urine collected from smokers and non-smokers among the general population and among occupationally exposed persons.ResultsThe elaborated method can be regarded as specific and sensitive procedure to quantify the seven different DHN. In human urine, we detected 1,2-DHN as main metabolite in 54 of the 55 analysed samples. Median 1,2-DHN values (range) were 1012 μg/L (22–6477 μg/L) for workers and 8 μg/L (