Comments on Van den Berg, et al. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. Environ Health Perspect 106:775-792 (1998)
Consistent with results from an earlier U.S. Environmental Protection Agency meta-analysis of three occupational cohorts, Crump et al. [Environ Health Perspect 111:681-687 (2003)] recently concluded that "dioxin TEQ [toxic equivalent] exposures within roughly 3-fold of current background levels may be carcinogenic" to humans. In contrast, my meta-analysis… (More)
The article by Madison et al. (1) contains major omissions, errors, and mis-statements which we feel compelled to bring to your attention. First and foremost is the authors' failure to mention the source of their funding. This study was funded by lawyers for approximately 70 persons (including all 42 of the "exposed subjects") (2). Rather than being merely… (More)
An important methodological challenge in the analysis of historical occupational cohort data is choosing the most appropriate metric for the average exposure of the workers under study. We describe and illustrate the many issues associated with this challenge using a recent re-analysis by Kopylev  of lung cancer mortality in the National Cancer Institute… (More)
A revised assessment of dichloromethane (DCM) has recently been reported that examines the influence of human genetic polymorphisms on cancer risks using deterministic PBPK and dose-response modeling in the mouse combined with probabilistic PBPK modeling in humans. This assessment utilized Bayesian techniques to optimize kinetic variables in mice and humans… (More)
Development and application of a global model for water withdrawals and availability. Hydrological Sciences, (in press).
Quantitative estimates of human carcinogenic risk from chemical exposure are currently derived primarily from linearized multistage model analyses of the tumor response as observed in chronic laboratory animal bioassays versus administered dose. The numerous ad hoc assumptions that provide a rationale for this generic approach to carcinogenic risk… (More)