This study investigated the relationship between Pb relative bioavailability (RBA) and bioaccessibility, and their relationships with Pb in different pools in soils. Twelve Pb-contaminated soils representing different contamination sources from China were analyzed for Pb bioaccessibility using four in vitro methods (UBM, SBRC, IVG, and PBET), Pb-RBA using a mouse blood model, and Pb fractionati...

[1] Trends and sources of lead (Pb) aerosol pollution in the North Pacific rim of North America from 1850 to 2001 are investigated using a high-resolution (subannual to annual) ice core record recovered from Eclipse Icefield (3017 masl; St. Elias Mountains, Canada). Beginning in the early 1940s, increasing Pb concentration at Eclipse Icefield occurs coevally with anthropogenic Pb deposition in ...

Phenobarbital (PB), a classical rodent hepatopromoter, remarkably enhances hepatocarcinogenesis initiated by diethylnitrosamine (DEN) in adult B6C3F1 mice. However, it is also known to strongly inhibit liver tumor development in the B6C3F1 mice initiated with DEN in their infancy. The present study aimed to elucidate the unknown biological mechanisms for this paradoxical, inhibitory effect of P...

Can a climate-triggered export of old contaminants from the soil alter the lead (Pb) contaminant burden of subarctic lakes? To address this question, we reconstructed the pollution history of three high latitude lakes situated in a region where a recent climatic shift has occurred. Dated sediment records were used as archives of past Pb inputs to the lakes, where the difference in the (206)Pb/(...

Two groups of schoolchildren between seven and 12 years old residing in the vicinity of a non-ferrous industrial plant and exposed to lead (Pb) at a concentration that could cause health problems, were monitored. Concentrations of Pb in blood (blood-Pb), which were determined at regular six monthly intervals, were related to the Pb concentrations in surface tooth enamel (enamel-Pb). Acid etch b...

Knowledge on the lithologically inherited variation in present day Pb isotope ratios in soils is remarkably limited. Such information is essential to determine the anthropogenic Pb fraction and anthropogenic Pb sources in Pb polluted soils. This study presents results of a survey of subsoil samples of approximately 350 rural locations covering the entire Netherlands, for which the bulk geochemi...

A method for the determination of Pb isotope ratios (IR) in cigarette tobacco by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) has been developed and applied to tobacco samples from genuine and counterfeit cigarettes obtained in the USA. The IR ²⁰⁷Pb/²⁰⁶Pb, (208)Pb/²⁰⁶Pb, ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb were measured using a Q-ICP-MS instrument. Two certified refer...

I. OVERVIEW AND SUMMARY The 401(k) plan is only about 20 years old, which means that individuals retiring today could have participated in 401(k) plans for at most half of a typical full working career. As more American workers participate in 401(k) plans and become increasingly responsible for their own retirement security, the question of whether their 401(k) accumulations will produce suffic...

OTHER HIGH-RESOLUTION CHRONOMETERS. Y. Amelin, M. Wadhwa, and G. Lugmair, Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada, Dept. of Geology, The Field Museum, 1400 S. Lake Shore Dr., Chicago, IL 60605, USA and The Chicago Center for Cosmochemistry, 5640 S. Ellis Ave., Chicago, IL 60637, Scripps Inst. of Oceanography, University of Calif. San Diego, La Jolla, CA 92...