No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Umwelt- und Gesundheitsschutz
Abstract
Schmierstoffe können bei sorglosem Umgang auf unterschiedliche Weise die Umwelt negativ beeinflussen bzw. die Gesundheit von Menschen schädigen. Wenn auch die Gefahr. für Umwelt und Gesundheit, die von modernen Schmierstoffen ausgeht, in beiden Fällen als gering einzustufen ist, so gilt es doch eine Reihe von gesetzlichen Regelungen aus dem Umweltrecht und aus dem Arbeitsschutzrecht vor, bei und nach dem Einsatz von Schmierstoffen zu beachten. Zu jedem Rechtsgebiet kommt jeweils ein verzweigtes untergesetzliches Regelwerk hinzu.
ResearchGate has not been able to resolve any citations for this publication.
A mixed culture of microbes from soil was used to attempt to degrade diesel fuel. The microbes were added to Erlenmeyer flasks containing 100 ml of an aqueous, inorganic nutrient and 2 ml of #1 diesel fuel. These mixtures were stirred continuously by magnetic stirrers for periods of one to six days. Controls were used with diesel fuel and nutrient but no microbes. After the given periods of stirring were completed, the remaining diesel fuel was extracted with benzene. Then, the extract was analyzed by gas chromatography. About one-half of the diesel fuel was degraded in two days. The gas chromatograms show that the straight chain alkanes were degraded faster than other hydrocarbons.
Since the technical literature was virtually devoid of data on the vapor pressure of greases and oils, a low cost apparatus was designed and built in the author's laboratory to measure the vapor pressure of lubricants at elevated temperatures and reduced pressure. A discussion of volatility and vapor pressure follows, along with a description of the test apparatus. The test results from eight oils and seven greases is discussed. (from Author)
Die Bezeichnung Erdölwachs (Mineralölwachs) hat sich international1 eingeführt, obwohl es sich der chemischen Struktur nach um feste Kohlenwasserstoffgemische und nicht um Wachse handelt2. Hierunter fällt als erstes in der Gruppe das natürlich vorkommende Erdwachs (Ozokerit), das am längsten bekannt ist. Es diente früher fast ausschließlich als Ausgangsmaterial zur Herstellung von Ceresin bis etwa zum Jahre 1920. Durch das gewaltige Anwachsen der Erdölindustrie wurde es — ungefähr gleichzeitig mit der Erschöpfung der Hauptfundorte in Polen — immer mehr durch das aus dem Erdöl abgeschiedene Petrolatum ersetzt, das heute das hauptsächliche Ausgangsmaterial für die Herstellung von Ceresin und Mikrowachsen ist3.
A literature search to identify deleterious effects of using re-refined oil did not disclose any validated occurrences. Significant engine testing using re-refined lubricating oil is reported and no cases were discovered in which engine operation was affected negatively by the use of re-refined oil. The American Petroleum Institute (AFT) allows the use of re-refined base stock oils in the blending of end use lubricants. Based on oil sample testing performed in this research as well as other authoritative sources, it was determined that no significant chemical or physical differences exist between rerefined and virgin oils. Differences noted in this research were related to higher levels of polynuclear aromatics (PNA’s) in the re-refined oil. PNA’s are formed due to the extreme conditions of temperature and pressure during operation of an internal combustion engine. PNA components are essentially removed by the hydrogenation process during re-refining ahd the trace amounts detected in new re-refined oil do not affect the oil’s physical performance characteristics. Similar levels of PNA’s were detected in used re-refined and used virgin oil, thereby indicating that the chemical change during use in an internal combustion engine is independent of the oil used. Lubricating fluid logistics and handling procedures were studied and recommendations related to the screening of suppliers and the use of purchasing specifications to insure the procurement of only qualified supplier’s products are presented. Purchasing specifications are generally acceptable but specific requirements must be stringently enforced to ensure that only quality lubricating products are purchased. Alternative contracting arrangements that offer lubricating fluid procurement and disposal cost savings are suggested. Suppliers have indicated interest in determining cost-effective approachs for supplying lubricants and collecting/disposing of used fluids. Although this research was performed for the Texas Department of Transportation (TxDOT) the recommendations presented are appropriate for other vehicle fleet operators.
The large number of sites which are contaminated with petroleum hydrocarbons after using petroleum products the last decades requires the investigation of the contaminations to get some information about the characteristics of the pollutants, the age of the contamination or the person responsible for the pollution. In most cases the age of the contamination is the key factor. The calculation of the age of contaminations with existing simulation tools is not possible with sufficient precision because of a number of not quantifiable parameters which have an influence on the degradation rates of the hydrocarbons. A combination of different testing methods with hydrological, geological, microbiological data and historical informations enables the determination of a time span when the accident has happened.
Based on the results of the optimization studies [1, 2] of waste oils hydrorening the optimal process parameters, temperature, hydrogen pressure and LHSV, were selected for two lubricating oil fractions. In the next step ca. 5 dm3 samples ofhydroreflning product of each fraction were obtained. Physicochemical properties of the hydrorening products were determined and compared with those of solvent raffinâtes obtained by solvent extraction of the waste oil fractions, and conventional base oils from crude oil. The waste oil hydmrefming products were used for blending different types of lubricating oils: engine oils, transmission oils and industrial oils.
In June 1983, experts from around the world met at the International Agency for Research on Cancer in Lyon, France, to review the available biological data on mineral oils. The working group concluded that there was no evidence of carcinogenicity with oils produced by severe solvent refining and severe acid refining. Other less severe treatments produce oils for which there is evidence of carcinogenicity in animal tests. Of particular importance is their conclusion that mineral oils used in the past in certain processes are carcinogenic to humans. This recognizes that the epidemiology studies evaluated probably included oils not representative of current refining practices. 8 refs.
This paper describes a study on oil mist systems for bearings and comments on measurement, evaluation and control. Results show that that stray mist in workplace areas is much below the permissible level of 5mg/m3. Stray mist can be excessive if the system is not properly applied or is overapplied. Oil type and the air temperature play a critical role in the richness or leanness of stray mist. Proper system design, good ventilation and use of good mistable lubricants can reduce stray mist to a low level.
The purpose of this paper is to describe what high-pressure injection injuries are, why these innocuous-appearing injuries should be considered surgical emergencies, and what is generally recommended as adequate treatment. Experience has shown that, although these injuries look innocuous, they are series and demand immediate medical attention. Injected material causes the most damage primarily by inducing an inflammatory response which results in a reduction or cessation of blood flow to an affected area. The outcome of an injury is highly dependent on the characteristics of the injected material as well as the prompt initiation of appropriate medical treatment. In most cases, surgery is the only means of restoring normal blood flow to an affects area. However, even with extensive surgery and other treatment measures, an injection injury may result in an irreversible impairment of function and/or amputation.
A solvent deasphalting process was recently tested and demonstrated as successful alternative for re-refining used motor oil. Choosing a commonly used grease, the lithium-12 hydroxy stearate grease, a controlled solvent extraction experiment was conducted to specifically evaluate the Residuum Oil Supercritical Extraction (ROSE) process. Compared with conventional solvent extraction processes, the ROSE process is shown to recover 93% of the extraction solvent, reduce operating costs, reduce the size and complexity of the plant, save capital costs, and save about 64% energy.
California has long been a national frontrunner on environmental issues, and used oil is no exception. In 1986, the California legislature passed a bill which made used motor oil a hazardous waste, and simultaneously began the long process to clean up the dirty practice prevalent in this business. Today, the state is collecting and recycling a greater percentage of its used oil, with less pollution than before, and much of the credit goes to a single company located in the San Francisco area, the Evergreen Oil, of Newark, California. Evergreen was started in the early 1980's as a joint venture between a used oil collector and a chemical engineering company. The two partners shared a dream - to build a modern state-of-the-art plant for recycling used oil into good lube oil. To achieve this dream, Evergreen had to solve problems of financing, permitting, technology, and marketing. From 1981 to 1986, used oil collections in the state grew from 50.6 million gallons to only 55.4 million gallons. By 1988, after Evergreen had been operating just two years, that number had grown to 82.7 million gallons.
In this study, results of regeneration of a used motor oil from an undefined collection are presented. This oil belongs to highly contaminated and thermally degraded mineral oils with a high content of additives. Advantages of this process are stressed provided that the vacuum distillation is performed under gentle conditions of molecular distillation with a short-term exposition and a low operating temperature during the regeneration. Qualitative parameters of both the raw regenerate after distillation and the regenerate after hydrofinishing are shown. These parameters are similar or better than those of the original base oil.
Metalworking fluid mist levels in eight manufacturing plants were surveyed using a RAM-1 or a DataRAM, light scattering device. Most levels fell in the 1 to 2.50 mg/m3 range, well within the present standards set by OSHA and ACGIH. Variations in observed mist levels were not determined by metalworking fluid type but by variables such as ventilation, temperature, humidity, fluid flow rate, and mist collection systems.
This paper highlights past and current work on the toxicity of petroleum lubricants and the base oils from which they are made. The review includes a discussion of short-and long-term toxicity studies carried out to determine potential hazards following skin contact, ingestion, or inhalation of petroleum products and covers the relationship between refining severity and the carcinogenicity of petroleum base oils.
This report will discuss worldwide legislation influencing base oil carcinogenicity screening, the methods most frequently used, theior applicability to various base oil types, and their level of predictability.
A fluid is typically sprayed onto cutting tool surfaces during the machining of metal automotive components. The cutting fluid greatly enhances the machining process and allows the mass production of components that meet engineering quality requirements. Unfortunately, the spraying and the high speed cutting action often atomize the fluid into very small droplets, creating a persistent, fog-like mist in the plant. Ambient mist in machining plants has been an ongoing environmental concern, in particular, its effect on workers' breathing zone air quality. The authors' approach was to reduce the amount of mist formed at the source by a simple rheological concept. Previous methods attempted to contain the mist once formed. The new approach exploits the ability of soluble, high molecular weight polymers to contribute significant elasticity to fluids at low concentrations. It was found that a small amount (less than 100 ppm) of polyisobutylene (PIB) was extremely effective in suppressing mist formation for straight mineral oil cutting fluids. Subsequent plant pilot tests confirmed these results, yielding 70-90% oil mist reductions using only 20-100 ppm PIB additions. In addition, no adverse impact was observed on the machined part quality or on fluid properties. Preliminary studies have shown the potential for the analogous development of mist suppressants for water-based cutting fluids.
The evolution of cleaner, more efficient engines requires the use of new lubrication technologies. A potential lubricant/lubrication technology must address the changing needs of engine designers and manufacturers. Specifically, this should include material and fuel compatibility, increased lubrication performance at elevated temperatures and pressures, ashless deposits, reduced particulate emissions and biodegradability. These are exactly the characteristics which vapor phase lubrication offers. With the correct choice of lubricant, vapor phase lubrication has been effective in reducing friction and minimizing wear of ferrous-rich stainless steels, tool steels, super alloys, ceramics and cermet composites at temperatures up to 67O°C under both sliding and rolling contact. This paper details the development of vapor phase lubrication with insights into material and lubricant selection, examples of successful applications development and current investigations by leading universities, government and commercial organizations alike.
Cutting fluids have to cover a dual function: to lubricate and to cool. In order to realize the lubricating and cooling process watermiscible and non-watermiscible metalworking fluids have to be formulated to cover first of all their ecological requirements. Based on the increasing awareness regarding environmental aspects, all components, base oils and additives, have to be selected very carefully in order to minimize any health problems and any impact to the environment. As a result, substitutions for some problematic components are being employed.
More than 200 species of bacteria, yeasts, and filamentous fungi have been shown to metabolize one or more kinds of hydrocarbons ranging from CH//4 to compounds containing more than 40 carbon atoms. Although there is a wealth of information on the occurrence and kinds of oil-degrading microorganisms in oil-polluted environments, not much is known about their reaction rates or their intermediate degradation products. Microorganisms which oxidize various hydrocarbons are widely distributed in soil and water. They are most numerous and the most varieties occur in places that have been subjected to chronic oil pollution either from natural seeps or by the activities of man. The rate at which polluting oils are degraded depends on the chemical composition of the oil, the kinds and numbers of microbes present, and several interrelated environmental parameters. Besides CO//2 and H//2O, the principal products resulting from the microbial degradation of hydrocarbons are various hydroperoxides, alcohols, phenols, carbonyls, aldehydes, ketones, and esters. The microbial oxidation of hydrocarbons is usually accompanied by the production of microbial biomass which may be decomposed by autolysis or by predators. Conspicuous by its absence is meaningful information on the absolute rates of biodegradation of oil pollutants.
A new class of shear stable polymers has been developed as mist suppressants for soluble oil, semi-synthetic and synthetic metalworking fluids. Laboratory screening tests and small-scale field tests (grinding and milling operations) were used to establish the mist suppression performance and durability of these polymers during development. Field testing was done at Ford Motor Company manufacturing plants to confirm the application, effectiveness and durability of these polymers in actual production environments. Strong correlation was measured between the results of laboratory screening tests and field evaluations. The manufacturing plant tests conclusively demonstrated the durable mist reduction performance of the polymers with significant, visible improvements in plant air quality. No adverse effects were observed on parts quality, normal production operations, coolant performance and waste treatability after polymer addition.
In the past, occupational skin cancer has been associated with the use of unrefined lubricating oils for various industrial processes. The carcinogenic constituents of these oils have been identified, and several refining techniques have been developed to remove or modify these hazardous components. It has been shown experimentally that highly refined oils do not produce skin cancer. The present study examines the dermal carcinogenic potential of lubricating oils produced by several refining processes and the products formulated from these oils. Consistent with previous data, it was found that highly refined oils are not carcinogenic, and that products formulated from these oils are similarly not carcinogenic provided that the additives are not carcinogenic. Additionally, the data also suggested that industrial usage does not influence the carcinogenic potential of these products. Thus, it is concluded that when noncarcinogenic additives are used in products formulated from high quality oils, the resulting products pose minimal skin cancer hazard when used under appropriate conditions for industrial applications.
Used oils, especially used lubricating oils which are normally considered waste and are discarded or burned, are reclaimed for reuse by a re-refining procedure involving the steps of: heat soaking the used oil; distilling the heat soaked oil; passing the distillate through a guard bed of activated material; hydrotreating the guard bed treated distillate under standard hydrotreating conditions. If the used oil to be re-refined contains a quantity of water and/or fuel fraction which the practioner considers sufficiently large to be detrimental, the used oil may be subjected to a dewatering/defueling step prior to being heat soaked.
In a previous study, it was found that when a nickel-based superalloy IN750 was heated to high temperatures, a passive layer of aluminum oxide formed on the surface, preventing vapor phase lubrication. In this study, two nickel-chrome-iron alloys and a nickel-copper alloy were studied for high temperature lubrication to see if these alloys, which contained small amounts of aluminum, would exhibit similar behavior. It was found that under static conditions, all three alloys formed a lubricious nodular coating when exposed to a vapor of aryl phosphate. Under dynamic sliding conditions at 500°C, these alloys were successfully lubricated with a coefficient of friction of 0.1 and no detectable wear. In order to explain these results, a direct correlation between successful vapor phase lubrication and the composition of the alloys containing aluminum has been proposed. If the ratio of copper/aluminum or iron/aluminum is greater that 100 vapor phase, lubrication will be successful. If the ratio is less than 10, a passive aluminum oxide layer will prevent vapor phase lubrication. By selecting alloys with a high iron or copper content, vapor phase lubrication can provide excellent lubrication at high temperatures. 14 refs., 11 figs., 1 tab.
General details are given of known satisfactory methods for sampling and analysis of mineral oil mists in atmospheric concentrations
approaching the threshold limit value.
A variety of potential health hazards associated with microbial infections of cutting oils have been postulated. This paper deals particularly with the inhalation of infected aerosols from such emulsions. An Andersen sampler detected up to 70000 viable bacteria/m3 of air 0.6m from a grinding machine in a machine shop, but this level decreased substantially further from the machine toolsPseudomonas aeruginosa, an accepted opportunistic pathogen, was present in the emulsions in the sumps and was detected in the air. However, when nasal swabs and sputum samples from 38 men were examined there was no indication that the respiratory tract had been colonised by Pseudomonas spp. It is suggested that the spoilage bacteria in the emulsions rapidly lose viability in an aerosol. The droplets however, are of a respirable size and dead bacteria may evoke respiratory response. Animal experiments indicated that infected emulsions exacerbate lung inflammation, serological responses and skin irritation
IT IS THE practice among some large users of ‘soluble’ cutting oils, such as motor manufacturers, to issue specifications imposing pH limitations on the oil in emulsion form. Although the limits fixed may vary widely among different users, the reasons for the particular level chosen are identical and invariably originate from the company medical department through their efforts to control factors likely to contribute to occupational dermatoses.
The article outlines physical and chemical properties of industrial lubricating oils that affect the performance and life of both the lubricant and machinery. Electrical conductivity and dielectric strength measurements are important criteria for monitoring transformer and insulating oils. Surface tension and interfacial tension can also monitored to see whether a oil is retaining its original properties. Contaminants of lubricating oils are classified into four areas: gaseous, liquid, solid particulates, and semi-solids. The contaminant`s method of entry, possible damaging effects, and detection by ASTM testing procedures are described.
The authors' company has characterised the potential human health and environmental hazards of widely used classes of lubricating oil additives and polyalphaolefin (PAO) base fluids in a battery of toxicity tests. The main classes of additives are: succinimide ashless dispersants, calcium sulphonates, calcium phenates, zinc dialkyldithiophosphates, oxidation inhibitors, and antiwear inhibitors. In summary, mammalian toxicity studies indicate that lubricant additives do not pose a significant health risk to humans. Ecotoxicity is also considered to be of low concern in general. Even though lubricant additives do not readily biodegrade, studies are under way to confirm that they are not persistent in the environment and that bioaccumulation is not a concern. Good Laboratory Practice (GLP) methods have been developed for analysis of additives involved in toxicity tests and for low concentrations (ppb) of additives in aqueous systems. Manufacturing advances are reducing the release of toxic by-products to the environment.
An examination has been made of the changes in bacterial and fungal populations during the decomposition of oil in contaminated soil. The number of aerobic and anaerobic bacteria and the length of mycelium increased in the oily soil whereas the number of CFU (= colony forming units) of fungi was highest in a control soil. The percentage of oil-utilizing fungi increased from 60% to 82%, while the bacterial utilization figure increased from 3% to 50%. The important oil-utilizing fungus Scolecobasidium appeared only in the oily soil, but otherwise the composition of the fungal flora changed only little after addition of oil. In laboratory experiments the chemical Pajab FI was shown to increase microbial activity.
Biodeterioration potentials of bacteria isolated from used car engine lubricating oil were examined using both used and unused oils as substrate. Used oil served as a better substrate for growth of the bacteria than unused oil. The bacterial isolates were identified as Bacillus, Corynebacterium, Actinomyces, Micrococcus, Serratia, Citrobacter, Edwardsiella, Pseudomonas, Nocardia and Acinetobacter species. Fungal genera isolated from the oil were Cladosporium, Aspergillus, Cephalosporium, Mucor, Monosporium, Penicillium and the yeast Saccharomyces. Incubation of the bacteria at different temperatures for 48 hours showed that 100% grew at 30°C, 56% grew at 45°C, 44% grew at 55°C, 31% grew at 60°C while 25% grew at 70°C and survived at 80°C. These results indicate that lubricating oil in service is more prone to biodeterioration than unused oil.
8. Aufl, 216. bis 223. Tausend
Publisher Summary
This chapter discusses the reaction between carbon monoxide and oxygen. Mixtures of carbon monoxide and oxygen exhibit the phenomenon of the first and second explosion limits. At pressures near the limit, the explosive reaction does not go to completion. The first limit is found to be erratically dependent on the nature of the surface and on vessel dimensions. Comparison with the H2-O2 system shows that the peninsula for the CO-O2 system lies in a much higher region of temperature and pressure. The second limit pressure decreases as the mole fraction of CO in the mixture is increased. Also the second limit pressure remains unaffected on replacing some of the CO-O2 mixture by an equal amount of nitrogen. The CO2 molecule formed in reaction, O + CO + M = CO2 + M, is in an electronically excited 3π state that is quenched in collisions with oxygen. Thus, another chain carrier is introduced into the mechanism and the reaction possibilities are correspondingly increased.
Thesis (Eng. D.)--Cleveland State University, 1992. Includes bibliographical references.
Bacterial degradation of motor oil was examined by using sediment samples from oil free and oil contaminated environments as inocula. Inoculated cultures were incubated under conditions optimizing growth and, in parallel experiments, conditions simulating the natural environment. Cell yields and the extent of degradation of the motor oil were measured. The inocula from oil contaminated environments produced greater growth on motor oil under simulated natural conditions than did inocula from oil free environments cultured under optimum conditions. The extent of biodegradation ranged from 62 to 70% under optimum conditions and from 40 to 57% under simulated natural conditions.
The environmental effects of adding certain selected petroleum products to field soils at widely separated geographical locations under optimum conditions for biodegradation were studied. The locations selected for study of soil biodegradation of six oils (used crankcase oil from cars, used crankcase oil from trucks, an Arabian Heavy crude oil, a Coastal Mix crude oil, a home heating oil no. 2, and a residual fuel oil no. 6) were Marcus Hook, Pennsylvania, Tulsa, Oklahoma, and Corpus Christi, Texas. The investigative process, covering a period of 1 year at each location, was conducted in 14 fields plots (1.7 by 3.0 m) to which the oils were added in a single application at a rate of 11.9 m3/4 X 10(3) m2. One-half of the plots at each location were fertilized, and the incorporation of the oils and fertilizers was accomplished with rototillers to a depth of 10 to 15 cm. Concentrations of all oils decreased significantly at all locations. The average reduction ranged from 48.5 to 90.0% depending upon the type of oil and location. Rates of degradation did not exceed 2.4 m3/4 X 10(3) m2 per month. Compositional changes in the oil with time were investigated using silica gel fractionation, gas chromatography, and ultraviolet absorbance. With the possible exception of the two fuel oils, the compositional changes were generally in the same direction for all of the oils. The silica gel fractionation and gravimetric data on residual oils show that all classes of compounds were degraded, but the more polar type degrade more slowly. Analysis of runoff water, leachate, and soils indicated that at the concentration applied no oil less was observed from these plots via water movement. No significant movement of lead compounds added to the soils in the used crankcase oils was observed. Significant increases in hydrocarbon-utilizing microorganisms were demonstrated in all treated plots using either the pure hydrocarbon, n-hexadecane, or the applied oils as the growth substrate. These increases were usually sustained throughout the year. Significant increases in hydrocarbon-utilizing fungi were not demonstrated by the plating technique used. The concentrations of residual oils or their oxidation products were of sufficient magnitude in the treated plots, 9 months after application, to cause significant inhibition of plant growth. From the data obtained, it was not possible to determine the type of compounds causing this inhibition or their long-term environmental effects.
Sprague-Dawley rats were exposed to aerosols of one of three base stocks used to formulate lubricating oils. These stocks were a solvent-refined oil (SRO), a hydrotreated and acid-washed white oil (WTO) and a severely hydrotreated and hydrocracked oil (HBO). Exposures were for 6 h per day, 5 days per week for ca. 4 weeks. There were four groups of rats for each study (10 per sex per group). Aerosol concentrations were ca. 0, 50, 210 and 1000 mg m-3 for each material; the mass median aerodynamic diameter was ca. 1 microns. Following the last exposure, all animals were sacrificed and necropsied. Samples were taken for serum chemistry, hematology, sperm morphology, weights of seven organs and histopathology on at least nine organs. Body weights and clinical signs were not affected by exposures. The only treatment-related changes were in the lung and associated lymph nodes. Both the wet weight of the lung and the dry/wet weight ratio increased in a concentration-related manner. Associated with the increased weight were accumulations of foamy alveolar macrophages, particularly in alveoli close to alveolar ducts. Mild infiltration by neutrophils was observed with WTO and SRO; thickened alveolar walls were noted with the highest concentration of HBO. These mild responses to exposures at very high concentrations indicate a low degree of toxicity for these aerosols.
The information concerning the effects of used motor oil on the environment is reviewed. The production and fate of used motor oil are analyzed and the effects on soil and aquatic organisms are described. The combustion of waste crankcase oil, with particular reference to environmental impact, is discussed. The mutagenic and carcinogenic effects of used motor oil are described. Information on the biodegradation of lubricating motor oil is also reviewed. The available information shows that used motor oil is a very dangerous polluting product. As a consequence of its chemical composition, world-wide dispersion and effects on the environment, used motor oil must be considered a serious environmental problem.
Microorganisms are sensitive to heavy metal pollution as are other components of the biota. However, most studies on the interactions between microbes and heavy metals have been conducted in synthetic media or in altered (e.g., sterilized) environmental samples and usually have used only single species. Few studies have evaluated the effects of heavy metals on the activities of natural heterogeneous microbial populations, both autotrophic and heterotrophic, in terrestrial and aquatic environments. These latter studies have shown that heavy metals inhibit primary productivity, nitrogen fixation, the mineralization of carbon, nitrogen, sulfur, and phosphorus, litter decomposition, and enzyme synthesis and activity in soils, sediments, and surface waters. The potential adverse effects of heavy metals on such microbe-mediated ecologic processes need to be incorporated into the methodologies used by regulatory agencies, such as the U.S. Environmental Protection Agency, to prepare environmental risk assessments which, in turn, are used to formulate environmental criteria, such as the Water Quality Criteria, and to evaluate the safety to the environment of exposure to "new chemical substances," as mandated by the U.S. Toxic Substances Control Act of 1976. To provide appropriate data that can be assimilated into regulatory policy, it is essential that microbial ecotoxicity tests be standardized, are neither costly nor difficult to train personnel to conduct, and produce data that can be quantitated.
Five experimental petroleum extracts were produced from luboil distillates derived from Middle East paraffinic crude by solvent extraction and severe hydrotreatment. The polycyclic aromatic content (PCA) of the extracts was determined by dimethyl sulphoxide extraction and ranged from 3.7-9.2% w/w. The five extracts were evaluated for their potential to induce cutaneous and systemic neoplasia in female mice derived from Carworth Farm No 1 strain (CF1). The test substances were applied undiluted (0.2 ml per application) to the shorn dorsal skin twice weekly for up to 78 weeks, with 48 mice in each treatment group and 96 in the untreated control group; two further groups, each of 48 mice, were similarly treated either with a non-hydrotreated commercial aromatic extract (PCA content, 19.7% w/v) or with a low dose of benzo(a)pyrene (12.5 micrograms/ml acetone). The mice were housed individually in polypropylene cages in specified pathogen free conditions. The incidence of cutaneous and systemic tumours was determined from histological analysis of haematoxylin and eosin stained tissue sections. The results were correlated with the PCA content of the extracts and compared with those from female mice exposed to a non-hydrotreated commercial aromatic extract. Four of the hydrotreated extracts were carcinogenic for murine skin; the two products with the lower PCA contents were less carcinogenic than the products with the higher PCA contents and all were less carcinogenic than the commercial extract. One extract with the lowest PCA content was non-carcinogenic. Thus refining by severe hydrotreatment was an effective method of reducing the carcinogenic potential of petroleum aromatic extracts. Although other physicochemical properties may influence the biological activity of oil products, the PCA content determined by dimethyl sulphoxide extraction may be a useful indicator of the potential of oil products to induce cutaneous tumours in experimental animals. There was no evidence that the commercial or hydrotreated extracts increased the incidence of systemic neoplasms when applied twice weekly to the dorsal skin.
Materials inhaled in the workplace can lead to all the major chronic lung diseases except those due to vascular disease. The physician should consider the possibility of occupational exposure when a working or retired adult presents with unexplained respiratory illness. Even exposure in office buildings1 and hospitals2 occasionally causes illness. Identifying a workplace-related cause of disease is important because it can lead to cure and to prevention for others. Because of differences in the metabolism and susceptibility of hosts, one occupational agent may cause many diseases, just as cigarette smoke causes several distinct disorders. Conversely, one respiratory disease may have . . .
Hautschutz beim Umgang mit Kühlschmierstoffen. Humane Prod.-Humane Arb
- S Becker
Bourne LB (1967) Skin disease from oil
- Bourne
Messen, Beurteilen und Schutzmaßnahmen beim Umgang mit komiexen kohlenwasserstoffhaltigen Gemischen
- Breuer