31 research outputs found
Body Burdens of Polybrominated Diphenyl Ethers among Urban Anglers
Polybrominated diphenyl ethers (PBDEs) have been widely used in the United States and worldwide as flame retardants. Recent PBDE production figures show that worldwide use has increased. To determine whether fish consumption is a source of PBDE exposure for humans, a cross-sectional epidemiologic study of New York and New Jersey urban anglers was conducted during the summers of 2001–2003. Frequency of local fish consumption was assessed by questionnaire, and blood samples for PBDE analysis were collected from 94 anglers fishing from piers on the lower Hudson River and Newark Bay. We analyzed PBDEs by gas chromatography–isotope dilution–high-resolution mass spectrometry. The congeners found in anglers’ serum at the highest concentrations were, by International Union of Pure and Applied Chemistry numbers, BDE-47, BDE-153, and BDE-99. Anglers reporting consumption of local fish had higher, but nonstatistically significantly different, concentrations of PBDEs than did anglers who did not eat local fish. For some congeners (BDE-100 and BDE-153), we observed moderate dose–response relationships between serum PBDE levels and frequency of reported fish intake. These findings suggest that consumption of locally caught fish is not a major route of human exposure for this study population
Retrospective time-trend study of polybrominated diphenyl ether and polybrominated and polychlorinated biphenyl levels in human serum from the United States.
Six polybrominated diphenyl ethers (PBDEs), one hexabromobiphenyl [polybrominated biphenyl (PBB)], and one hexachlorobiphenyl [polychlorinated biphenyl (PCB)] were measured in 40 human serum pools collected in the southeastern United States during 1985 through 2002 and in Seattle, Washington, for 1999 through 2002. The concentrations of most of the PBDEs, which are commercially used as flame retardants in common household and commercial applications, had significant positive correlations with time of sample collection, showing that the concentrations of these compounds are increasing in serum collected in the United States. In contrast, PCB and PBB levels were negatively correlated with sample collection year, indicating that the levels of these compounds have been decreasing since their phaseout in the 1970s
TU Tau B: The Peculiar 'Eclipse' of a possible proto-Barium Giant
TU Tau (= HD 38218 = HIP 27135) is a binary system consisting of a C-N carbon
star primary and an A-type secondary. We report on new photometry and
spectroscopy which tracked the recent disappearance of the A-star secondary.
The dimming of the A-star was gradual and irregular, with one or more brief
brightenings, implying the presence of nonhomogeneities in the carbon star
outflow. We also present evidence that the A-star is actively accreting
s-process enriched material from the carbon star and suggest that it will
therefore eventually evolve into a Barium giant. This is an important system as
well because the A-type star can serve as a probe of the outer atmosphere of
the carbon star.Comment: 9 pages, 9 figures, 4 tables, a number of amateur observatories made
significant contributions to this research. Paper accepted for publication in
The Astronomical Journa
Voicing One's Dreams: High School Students with Developmental Disabilities Learn about Self-Advocacy
Tech Topics [Volume 40, Number 1, Fall 2003]
Full-page advertisements have been removed from this issue