For BEs based on noncancer end points (e.g., RfDs, MRLs), hazard quotients (HQs) were calculated as follows: HQ values near or above 1 provide an indication that exposure levels are near or above the exposure benchmark underlying the BE value.
In addition, 51% and 65% of the probability density distribution in predicted SMRs and RRs, respectively, fells above 1.0 (no risk) at the lowest exposure benchmark of 10 μg/L, with these proportions increasing to 74% and 83% for SMR and RR at levels of 50 μg/L.
Thus, interference with mammary gland development in mice with developmental exposure seems to occur at low exposures; benchmark dose calculations using a variety of models showed that a 10% BMR corresponded to a serum-based BMDL for PFOA of 23 25 μg/L (or ng/mL) [ 12, 17].
In addition, there is some evidence that exposure to benchmarking examples and feedback improves an individual's ability to self-assess accurately (Lane and Gottlieb 2004; Martin et al. 1998).
The reference dose was chosen based on previous studies that showed strong inflammatory and genotoxic responses following instillation of this dose of NPCB and because we routinely include NPCB as a benchmark exposure [Saber et al., 2011a, b, 2012].
In addition, all the previous studies on U-Cd and BMD (Hong et al. 2004; Jin et al. 2004; Uno et al. 2005) categorized the exposure into strata (Benchmark Dose Software; U.S. EPA, Washington, DC, USA).
The NOTEL may be a relevant indicator of biological exposure to quickly benchmark toxic doses of chemicals and mixtures, especially within the framework of large toxicology programs such as REACH [ 13, 14].
The model predicted that when homes did not use venting range hoods, household exposures frequently exceeded benchmarks the authors set based on federal and state health-based standards., It also indicated that cooks and young children, who were assumed to be in closest proximity to the stove, would have the highest exposures.
Two ETNs, the iPath GSCI Total Return Index and the iPath Dow Jones-AIG Commodity Index Total Return, offer exposure to broad commodities benchmarks.
The risk assessment was conducted using the margin of exposure (MOE) approach with benchmark doses obtained from dose-response modelling of animal experiments.
