Evaluating the toxicokinetics of some metabolites of a C6 polyfluorinated compound, 6:2 fluorotelomer alcohol in pregnant and nonpregnant rats after oral exposure to the parent compound.

The 6:2 fluorotelomer alcohol (6:2 FTOH) is a common impurity in per- and polyfluoroalkyl substances (PFASs) used in many applications. Our previous toxicokinetic (TK) evaluation of 6:2 FTOH calculated times to steady state (tss) of one of its metabolites, 5:3 fluorotelomer carboxylic acid (5:3A), in the plasma and tissues of up to a year after oral exposure to rats. Our current work further elucidated the TK of 5:3A and other metabolites of 6:2 FTOH in pregnant and nonpregnant rats after repeated oral exposure and examined the role of renal transporters in the biopersistence of 5:3A.

Isoliquiritigenin Decreases Bone Resorption and Osteoclast Differentiation.

Scope: A dose-ranging study is performed using young estrogen-depleted rats to determine whether dietary isoliquiritigenin (ILQ) alters bone metabolism and if the effects are associated with estrogen receptor signaling.

Methods And Results: Six-week-old rats (ovariectomized at 4 weeks of age) are fed diets containing 0, 100, 250, or 750 ppm ILQ (n = 5/treatment) for 7 days. Gene expression in femur and uterus, blood markers of bone turnover, body composition, and uterine weight and epithelial cell height are determined.

Advancing human health risk assessment.

The current/traditional human health risk assessment paradigm is challenged by recent scientific and technical advances, and ethical demands. The current approach is considered too resource intensive, is not always reliable, can raise issues of reproducibility, is mostly animal based and does not necessarily provide an understanding of the underlying mechanisms of toxicity. From an ethical and scientific viewpoint, a paradigm shift is required to deliver testing strategies that enable reliable, animal-free hazard and risk assessments, which are based on a mechanistic understanding of chemical toxicity and make use of exposure science and epidemiological data.

A Summary Report of FSCJ Workshop "Future Challenges and Opportunities in Developing Methodologies for Improved Human Risk Assessments".

This is a summary report of FSCJ (Food Safety Commission of Japan) workshop entitled "Future Challenges and Opportunities in Developing Methodologies for Improved Human Risk Assessments, which held in November 2018. Scientific advancements have facilitated the development of new methods for chemical risk assessments with the expansion of toxicological databases. They are promising tools to overcome challenges, such as situations of data insufficiency, estimation of internal exposure and prediction of hazard, and enable us to improve our human health risk assessment in food safety.