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Biomedical subjects

L Fishbein

Publications and source records attributed to L Fishbein.

At least 19 recordsLinked to original sources
PubMed1992

Exposure from occupational versus other sources.

There is an increasing need to consider the various routes of exposure to individuals in occupational settings, as well as the exposure of the general public to a broad spectrum of carcinogens. The need to consider indoor environments is increasingly recognized in light of the amount of time spent indoors by a large majority of the population and the recognition that levels of certain toxicants are higher indoors than outdoors. This overview highlights (i) a general comparison of exposure to indoor and outdoor levels of 12 volatile organic compounds and (ii) the exposure of workers and the general public to benzene, 1,3-butadiene, formaldehyde, styrene, tetrachloroethylene, phthalate esters, polychlorinated dibenzofurans, radon, and electromagnetic fields.

Air Pollution, Indoor↗
PubMed1992

Technological changes in cancer prevention.

Exposures and technologies in the workplace are changing due to a variety of factors, including newly developed technologies, mechanization and automation, and improvements in industrial hygiene primarily effected in many developed countries. In addition substitution and removal of carcinogenic constituents in the workplace and general environment are increasing in a number of instances, particularly in North America, Western Europe, and Japan, and they are being accompanied as well by remediation either by source reduction, recycling, or compliance to more stringent national and international regulations and standards. This overview highlights some of the strategies employed in the technological changes in cancer prevention and cites examples in source reduction, changes in formulation, product or process changes, recycling, and hazardous materials management.

Hazardous Substances↗
PubMed1991

Chemicals used in the rubber industry.

Hundreds of chemicals and mixtures illustrative of many structural and use categories are employed in the rubber industry. Global utilization of natural rubber and synthetic elastomers as well as rubber-processing chemicals are projected to increase in the foreseeable future. Primary focus is centered on the major rubber processing chemicals and elastomer monomers in regard to their utility, production trends, structural characteristics, nature of potential impurities, and toxicology (primarily carcinogenicity and genotoxicity). Additionally, areas of specific exposure concern and epidemiology in the rubber industry are considered.

Animals↗
PubMed1991

Approaches for assessing health risks from complex mixtures in indoor air: a panel overview.

Critical to a more definitive human health assessment of the potential health risks from exposure to complex mixtures in indoor air is the need for a more definitive clinical measure and etiology of the health effects of complex mixtures. This panel overview highlights six of the eight presentations of the conference panel discussion and features a number of the major topical areas of indoor air concern. W. G. Meggs assessed clinical research priorities with primary focus on the role of volatile organic chemicals in human health, recognizing the areas where definitive data are lacking. By recognizing many types of chemical sensitivity, it may be possible to design studies that can illuminate the mechanisms by which chemical exposure may cause disease. The critically important topic of multiple chemical sensitivity was discussed by N. A. Ashford, who identified four high risk groups and defined the demographics of these groups. P. A. Schulte addressed the issue of biological markers of susceptibility with specific considerations of both methodological and societal aspects that may be operative in the ability to detect innate or inborne differences between individuals and populations. Three case studies were reviewed. H. Anderson discussed the past and present priorities from a public health perspective, focusing on those issues dealing with exposures to environmental tobacco smoke and formaldehyde off-gassing from materials used in mobile home construction. J. J. Osborne described several case studies involving wood smoke exposure to children, with emphasis on the significantly greater occurrence of chronic respiratory symptoms and acute chest illness for children from homes heated with woodburning stoves.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollution, Indoor↗
PubMed1988

Fructooligosaccharides: a review.

Fructooligosaccharides are naturally occurring compounds that have been reported in a variety of plants. Neosugar is a fructooligosaccharide mixture of 1F-(1-beta-fructofuranosyl)-sucrose polymers which is produced on a commercial scale from sucrose using a fungal fructosyltransferase. The resulting product is 0.4 to 0.6 times as sweet as sugar and is resistant to digestion by mammalian alpha-amylase, sucrase and maltase. Although Neosugar is non-digestible in humans, it is selectively utilized by bifidobacteria. Neosugar has been examined extensively in human and animal studies which indicate a lack of toxicity, carcinogenicity and genotoxic effects. Neosugar is used as a feed additive for poultry and swine in Japan and has been approved in foods as a raw material. Additional studies in progress in the US suggest that it could provide an economic alternative as an additive to poultry and swine feed.

Animals↗
PubMed1987

Perspectives of analysis of carcinogenic and mutagenic metals in biological samples.

There is a continuing need to assess the status of exposure to humans of the carcinogenic and/or mutagenic metals in both biological and environmental samples to better ensure that current or past exposures do not entail unacceptable health risks or to detect potentially excessive exposure before the appearance of adverse health effects. In order to more readily evaluate both the extent of exposure and trends of human exposure as well as the bioavailability, bioaccumulation and transport of these elements and their compounds, sensitive analytical procedures are required for their determination of the various oxidative states (as well as their organic derivatives) in complex matrices such as those found in both environmental and biological samples. The major objective of this overview is to highlight the more recent trends and state-of-the-art methodologies for the determination and speciation of arsenic, selenium, cadmium, chromium and nickel in human and animal tissues while concomitantly noting germane aspects of their bioavailability and interactions. Aspects of biological monitoring of the above elements will be stressed due to their potential utility in augmenting diverse epidemiologic and occupational health studies.

Animals↗
PubMed1987

Health-risk estimates for 2,3,7,8-tetrachloro-dibenzodioxin: an overview.

As has been abundantly noted by many investigators, the paucity of definitive knowledge of metabolism, pharmacokinetics and pathogenesis of the chlorinated dioxins, principally 2,3,7,8-TCDD, in human populations continues to severely limit our ability to evaluate the scope of the chronic and delayed effects of exposure to these agents. The marked qualitative and quantitative differences in the response of animals to TCDD plus the inability to validate a number of the critical assumptions and mathematical models relative to risk assessment make the extrapolation of data from intact animals to man particularly uncertain. Hence, it is vital to vigorously pursue the elaboration of the mechanism of action of TCDD at the molecular level. This should greatly contribute to our fundamental understanding of this agent and the potential danger that it may pose for man.

Accidents, Occupational↗
PubMed1987

Perspectives on occupational exposure to antineoplastic drugs.

This review has attempted to focus on the salient features of the potential risks of occupational exposure to the major antineoplastic agents that have broad utility in cancer chemotherapy, as well as in the treatment of a spectrum of refractory non-malignant conditions. An initial focus centered about the classes (primarily alkylating agents, antimitotics, antibiotics, and antimetabolites), types of action and their carcinogenicity, genotoxicity, and reproductive effects exhibited by many of these agents in animals and treated patients. Nurses, pharmacists, and oncologists are the principal individuals with a potential risk to these agents primarily during the preparation and administration of these agents. Although the number at potential risk are not known precisely, they are believed to be relatively small in the aggregate, perhaps numbering several thousand. The measurement of exposure has generally been attempted on a relatively small number of nurses and pharmacists by biological monitoring employing urinary mutagenicity assays and cytogenetic analysis with conflicting results. The levels of exposure currently found are low compared to the therapeutic doses employed and are probably much lower than that which may have occurred earlier before the employment of vertical laminar flow hoods and the more recent implementation of guidelines and/or recommendations. The long-term effects of exposure to occupational personnel at potential risk of exposure to chemotherapeutic agents and waste are not known. Although studies to date have failed to show conclusively that nurses and pharmacists are at risk to the carcinogenic, genotoxic and reproductive effects of these agents, prudence would dictate that every effort be taken to minimize their exposure during the handling and disposal of antineoplastic drugs.

Antineoplastic Agents↗
PubMed1986

A toxicological review of beta-adrenergic blockers.

The use of various beta-adrenergic blockers has become extensive as they have been found to be efficacious in the treatment of a number of cardiovascular problems including cardiac arrhythmias, angina pectoris, and hypertension. The widespread and chronic use of these drugs has generated a concern for their potential chronic toxicity. Eighteen beta-adrenergic blockers have been reviewed and the available literature pertaining to their potential carcinogenicity, mutagenicity, and teratogenicity has been summarized and compared.

Acebutolol↗
PubMed1986

An IARC Manual series aimed at assisting cancer epidemiology and prevention. "Environmental carcinogens: selected methods of analysis".

Since 1975, the IARC has been preparing a series of volumes entitled "Environmental Carcinogens: Selected Methods of Analysis" (IARC Manual series) of which the purposes are to assist analysts, epidemiologists and regulatory authorities in planning or performing exposure measurements that are truly comparable between different studies. The Manual series provides expert information within each volume on multi-media sampling, methods of analyses and some background of epidemiology, metabolism, use/occurrence for a group of known or suspect carcinogens. So far, eleven volumes have been published or are in preparation on the following subjects: N-nitrosamines, vinyl chloride, PAH, aromatic amines, mycotoxins, N-nitroso compounds, volatile halogenated hydrocarbons, metals, passive smoking, benzene and alkylated benzenes, dioxins, PCDFs and PCBs. The presentation will discuss needs and priorities for use of analytical chemistry in estimating exposures of apparently greatest relevance to cancer causation, i.e. the approach to developing this series. Indications from epidemiology, evaluations of carcinogenic risk to humans, and recent developments in total exposure assessment are that new methods and matrices need more emphasis, e.g. as with biochemical dosimetry, exhaled breath, and in indoor air.

Carcinogens, Environmental↗
PubMed1986

Contribution of organic particulates to respiratory cancer.

This paper presents some of the issues that remain to be resolved in order to assess the risk of cancer related to exposure to organic particulates. Most reviews of the effects of organic particulates from the outdoor environment on the risk of lung cancer show that this source seems to play a minor role. However, as fuel use and chemical composition of air pollutants change, the contribution of outdoor pollution as a cause of cancer may also change. Indoor air pollution is a more important source of exposure to organic particulates than is outdoor exposure. Although there is clear evidence that in occupational settings organic particulates cause human cancer, there has been almost no study of exposure to these types of particulates within indoor settings. Previous research has focused on cigarette smoke as the major indoor pollutant, but more specific characterization of contaminants in both the workplace and the home is required. The health effects of the higher levels of some of these contaminants in the workplace should be evaluated and the results extrapolated to populations exposed to lower levels in the home. Extensive research is needed to characterize organic particulate mixtures appropriately and test them for carcinogenicity. Studies on the health risks of nitropolynuclear aromatic hydrocarbons and polychlorinated dibenzodioxins and dibenzofurans are reviewed, but their contribution to the overall burden of respiratory cancer in humans cannot be estimated at this time. Characterization of mixtures, assessment of exposures, and linkage of exposures to health effects are the objectives of the recommendations proposed for further research.

Air Pollutants↗
PubMed1986

Perspectives in metal carcinogenesis. I. Selenium.

This review has focused primarily on the sources of exposure to selenium and its role as an antioxidant as well as its anticarcinogenic and antimutagenic properties. Selenium is an essential trace element and a constituent of glutathione peroxidase in human erythrocytes. Numerous studies with animals have demonstrated that it is a potent inhibitor of virally- and chemically-induced tumorigenesis when administered continuously in a variety of tumor systems (predominantly in the skin, liver, colon, and mammary gland). The mechanisms by which selenium inhibits tumorigenesis is not definitely known. Several epidemiological studies have demonstrated statistically significant inverse associations between human cancer mortalities in different populations. In these studies, the regional availabilities of selenium were measured via a variety of means, including blood selenium levels, the concentration of selenium in grains and forage crops or from calculated apparent selenium intake estimated from food consumption and consumption data. These animal and human studies demonstrating inverse associations between tumorigenesis and selenium levels have led to suggestions that selenium be considered a prophylactic agent in the chemoprevention of tumorigenesis. It would appear prudent to avoid the unnecessary supplementation of normal diets with selenium.

Air Pollutants↗
PubMed1985

An overview of environmental and toxicological aspects of aromatic hydrocarbons. III. Xylene.

The commercial product "mixed xylenes" (a technical product generally containing approximately 40% m-xylene and 20% each of o-xylene, p-xylene and ethylbenzene, as well as small quantities of toluene) analogously to toluene is an agent of major chemical and occupational significance. It is produced in very large quantities and is extensively employed in a broad spectrum of applications, primarily as a solvent for which its use is increasing as a "safe" replacement for benzene, and in gasoline as part of the BTX component (benzene-toluene-xylene); xylenes are also frequently used in the rubber industry with other solvents such as toluene and benzene. As individual isomers they are extensively employed in the synthesis of synthetic agents, for example phthalic acid, isophthalic acid, terephthalic acid and dimethylterephthalate, which have very broad applications in the further preparation of phthalate ester plasticizers and components of polyester fiber, film and fabricated items. There is a broad potential for exposure both to industrial workers in the production and use of the xylenes and to the general public (via vehicle exhausts, consumer products, etc). Compared with benzene and toluene, very much less is known of the human health hazards, particularly the chronic effects of xylenes, either as mixed xylenes, as individual isomers or in admixture with other alkylbenzenes. It is of importance to note that coal-based solvents (e.g., xylene) have been suggested to be possible potent lymphocytic leukemogens, such as benzene, in a limited study of the relationship between lymphocytic leukemia and exposures to benzene and other solvents in the rubber industry. Available animal data on the carcinogenicity of xylene(s) are inadequate to permit an evaluation. Mixed xylenes are currently being investigated in a chronic bioassay by the National Toxicology Program. In limited studies thus far, the individual isomers have not been found genotoxic when tested in a number of short-term tests.

Biological Transport↗