Inhalation exposure or body burden? Better way of estimating risk - an application of PBPK model

Publication date: Available online 12 November 2015 Source:Environmental Toxicology and Pharmacology Author(s): Dipanjali Majumdar, Chirasree Dutta, Subha Sen We aim to establish a new way for estimating the risk from internal dose or body burden due to exposure of benzene in human subject utilizing physiologically based pharmacokinetic (PBPK) model. We also intend to verify its applicability on human subjects exposed to different levels of benzene. We estimated personal inhalation exposure of benzene for two occupational groups namely petrol pump workers and car drivers with respect to a control group, only environmentally exposed. Benzene in personal air was pre-concentrated on charcoal followed by chemical desorption and analysis by Gas Chromatography equipped with Flame Ionisation Detector (GC-FID). We selected urinary Trans, trans-Muconic Acid (t,t-MA) as biomarker of benzene exposure and measured its concentration using solid phase extraction followed by High Performance Liquid Chromatography (HPLC). Our estimated inhalation exposure of benzene was 137.5, 97.9 and 38.7μg/m3 for petrol pump workers, car drivers and environmentally exposed control groups respectively which resulted in urinary t,t-MA levels of 145.4±55.3, 112.6±63.5 and 60.0±34.9μg/g of creatinine, for the groups in the same order. We deduced a derivation for estimation of body burden from urinary metabolite concentration using PBPK model. Estimation of the internal dose or body burden of be...
Source: Environmental Toxicology and Pharmacology - Category: Environmental Health Source Type: research