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Biomedical subjects

W D Scott

Publications and source records attributed to W D Scott.

10 recordsLinked to original sources

Cembrene A and a congeneric ketone isolated from the paracloacal glands of the Chinese alligator (Alligator sinensis).

A diterpene hydrocarbon and diterpene ketone isolated from the paracloacal gland secretions of the Chinese alligator (alligator sinensis) were examined by GC-MS and 1H-NMR, 13C-NMR, and IR spectroscopy, and identified as 4,8,12-trimethyl-1-(1-methylethenyl)-3,7,11-cyclotetradecatrien e (cembrene A, 1) and its congeneric ketone, 4,8,12-trimethyl-1-(1-methylethenyl)-3,7-cyclotetradecadien- 10-one (2), respectively. This is the first report of cembrene A from a vertebrate; the ketone has not been described previously.

Alligators and Crocodiles↗

Lung cancer in ferrous foundry workers: a review.

Epidemiologic studies indicate that an increased incidence of lung cancer may be associated with specific work areas in ferrous foundries. With the exception of crane operators, who were found to have an elevated lung cancer rate in one foundry, the excess lung cancer incidence is generally confined to molders, casters, and cleaning room operators whose lung cancer risk is two- to threefold higher than that of standard populations. These studies reflect conditions that existed in the foundries several decades ago. The lung cancer risk today may differ as a result of the introduction of new foundry practices and the use of new molding materials. Benzo(a)pyrene and certain other polycyclic aromatic hydrocarbons have been found in many locations in the foundries. It is not known if tumor promoters, co-carcinogens, or other classes of chemical carcinogens are present. The contribution of tobacco smoke to the lung cancer risk of ferrous foundry workers is also unknown. Current studies are examining the composition and long-term health effects of emissions from molds composed of modern synthetic chemical molding materials as well as those from the more traditional green sand molds.

Animals↗

Nitrogen-containing compounds in foundry mold emissions.

Nitrogen compounds have been identified in the decomposition products from several commonly used foundry sand binders. These compounds include nitrogen oxides, hydrogen cyanide, ammonia, simple aromatic amines, and isocyanates. The concentrations of these compounds in foundry mold emissions do not appear to be directly related to the nitrogen content of the organic binders. Measurable concentrations were observed in some cases, indicating the necessity for periodic, monitoring in the foundry. Adequate ventilation will permit the use of these binders. The substitution of nitrogen-free binders suggests another possible control strategy.

Air Pollutants↗

Thermal and mechanical properties of aluminized fabrics for use in ferrous metal handling operations.

Protective garments are normally worn in molten handling operations to provide some protection against molten metal splashes. These garments are also intended to provide protection against radiant heat, and they should be as heat resistant and comfortable as possible. Asbestos-based fabrics have been employed for many years, but recently some concern has been expressed over possible asbestos exposure. This program was undertaken to explore the ability of several types of fabrics to resist heat transfer during molten metal impact. A molten metal splash test, along with standard methods for determining tensile strength, flame resistance, and abrasion-flexing resistance were used to evaluate several classes of protective fabrics. The results indicate that there are materials available that offer equal or better mechanical properties and thermal protection compared to aluminized asbestos.

Aluminum↗

Foundry air contaminants from green sand molds.

The major gases evolved from foundry molds have been determined in the laboratory. The principal gases evolved during pouring and shakeout of castings include hydrogen, carbon monoxide, carbon dioxide, methane and other low molecular weight hydrocarbons with smaller amounts of ammonia, hydrogen cyanide, and sulfur dioxide.

Air Pollutants↗

A preliminary investigation of the organic chemical emissions from green sand pyrolysis.

Condensable effluents from the thermal decomposition of a typical green sand foundry mold were investigated for the presence of emissions that could present health hazards in a foundry atmosphere. The benzene-soluble fraction extracted from the condensate was analyzed by gas chromatography/mass spectrometry. Over 200 compounds were observed on the chromatograms and benzo(a)pyrene, benzo(e)pyrene and perylene were identified. The concentrations of these materials were not determined, but their presence in foundry atmospheres represents in area of potential concern for health welfare.

Air Pollutants↗

Relative sensitivities of viruses to different species of interferon.

Some viruses were found to be more sensitive than others to the action of interferons from certain species of animals but less sensitive to interferons from other species. Vaccinia virus was the most sensitive to mouse and hamster interferons of five viruses tested, but the least sensitive of these five viruses to human, rabbit, and bat interferons. The relative sensitivities of the viruses to interferons were found to be characteristic for each of the species tested, with those closely related phylogenetically exhibiting similar patterns of relative interferon-induced virus resistance. The amount of synthetic double-stranded polynucleotide polyinosinic acid-polycytidylic acid required to induce resistance to each of the viruses in each of the cell species correlated with the interferon sensitivities of the viruses.

Animals↗

Assessing asbestos exposure potential in nonindustrial settings.

The presence of asbestos containing materials (ACM) in office and commercial buildings is a significant environmental problem. Asbestosis, mesothelioma and lung cancer have been linked with industrial exposure to airborne asbestos. The extensive use of asbestos products in buildings has raised concerns about the widespread exposure of the general public to asbestos in nonoccupational settings. The presence of asbestos in a building does not necessarily mean that significant exposure of the occupants of the building has occurred, but it is important that the asbestos be monitored regularly to ensure that fibers do not become airborne. If ACM are contained within a matrix and not disturbed, exposure is unlikely. However, if the asbestos becomes friable (crumbling) or if building maintenance, repair, renovation or other activities disturb ACM, airborne asbestos fibers may be a source of exposure to the occupants of the building. Currently, asbestos exposure assessment is conducted by a phase contrast light microscope (PCM) technique. Due to its inherent limitation in resolution and the generic counting rules used, analysis by the PCM method underestimates the airborne asbestos fiber concentration as compared to analysis by transmission electron microscopy (TEM). It is important that the air monitoring results analyzed by PCM be interpreted carefully in conjunction with a survey by a professional to judge the physical condition of the ACM in buildings. Exposure levels to airborne asbestos fibers vary from day to day and depend on the physical condition of the material involved and the type of operating and maintenance program in place.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollution↗