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Biomedical subjects

A N Rohl

Publications and source records attributed to A N Rohl.

At least 19 recordsLinked to original sources
PubMed1985

Airborne fiber control in buildings during asbestos material removal by amended water methodology.

Removal of friable asbestos-containing material can cause high levels of airborne contamination. The potential efficacy of control methods recommended by the Environmental Protection Agency (EPA) was evaluated by examination of 503 air samples obtained in 40 removal projects in a number of locations. The EPA methodology with amended water for fiber emission control was utilized on all of the observed removal projects. The projects were also considered to be well controlled and the study cannot be considered representative of common work practices. The EPA amended water methodology, when effectively utilized and administered, can provide a high degree of contamination control. Mean fiber levels in the work area in this study (1.1 f/cm3) were well below those of dry removal (38.9 f/cm3) and control by application by untreated water (28.6 f/cm3). Airborne contamination was higher during bagging debris (3.8 f/cm3) than during material removal from structural surfaces. The range of fiber levels during removal was 0.0 to 37.0 f/cm3 and fibers were detected from initial barrier construction through final cleaning. Contamination was also occasionally detected outside work area containment barriers. Air sampling produced 0.0 counts in areas of obvious contamination by settled dust and debris. Control methodologies, respiratory protection, and decontamination are discussed.

Air Pollutants↗
PubMed1985

Interstitial pulmonary fibrosis in an automobile body shop worker.

Interstitial pulmonary fibrosis (IPF) is often of uncertain etiology and is therefore named 'idiopathic' pulmonary fibrosis. Some occupational exposures, however, are known to cause interstitial fibrosis, asbestos and silica being well-known examples. We present clinical and pathological findings of a case with IPF and the results of microchemical analysis of inorganic particulate matter in the lung tissue. A very high lung burden of inorganic contaminants was found, including silica and metallic compounds. Emphasis is given to the importance of obtaining detailed occupational histories and conducting microchemical analysis of lung tissue in order to clarify etiological factors in cases with 'idiopathic' pulmonary fibrosis.

Aged↗
PubMed1982

Endemic pleural disease associated with exposure to mixed fibrous dust in Turkey.

Pleural mesothelioma, lung cancer, pleural calcification and fibrosis, and interstitial parenchymal fibrosis have been observed among inhabitants of several villages in south-central Turkey. Earlier reports have stated that environmental and lung tissue samples from this area contained the fibrous zeolite mineral erionite, and this mineral has generally been assumed to be the agent responsible for these endemic pathological conditions in the absence of asbestos outcroppings and usage. Several different kinds of asbestos minerals in addition to erionite have now been found in environmental samples taken from the villages where these diseases occur. The lung tissues of mesothelioma patients from these villages contain both fibrous zeolites and asbestos minerals.

Dust↗
PubMed1982

Lead poisoning in an art conservator.

A case of lead poisoning in a female art conservator is reported. The patient had experienced excessive lead exposure while restoring an antique Peruvian tapestry from the Chancay period (1000 to 1500 AD) using a powdered pigment (cinnabar), which had been recovered from the same tomb in which the tapestry was found. Over two months, prominent neurological, gastrointestinal, and diffuse muscular symptoms developed. Severe anemia accompanied by basophilic stippling of RBCs led to the diagnosis of lead poisoning, which was confirmed by markedly elevated blood lead levels (up to 130 micrograms/dL) and impairment of heme synthetic enzymes. The severity of the intoxication necessitated chelation therapy. Chemical analysis of the antique powdered pigment showed it to be the source of lead exposure, in that it contained about 1% lead.

Adult↗
PubMed1982

Asbestos-related diseases. Algorithm for forensic pathological diagnosis.

The pathological diagnosis and proof of asbestos causation in environmental-occupational diseases is based on a spectrum of increasingly sophisticated determinations with greater confidence in detection of asbestos bodies and fibers. These include the following: pathology (histology) and/or thick smears of lung, microincineration, bulk chemical digestion, and electron beam instruments. The requisites of medical and forensic asbestos causation differ, and do not always require the full range of these analytical techniques. The need and significance of some of these determinations, as expressed in number of asbestos bodies and fibers, may be related in many cases to the evidence of asbestosis; to the gross and microscopic pathological findings (asbestosis, lung carcinoma, mesothelioma); the exposure history (type, duration, intensity, and period of latency); and nature of the asbestos mineral. An algorithm for the forensic pathological diagnosis of asbestosis and of asbestos-related diseases is proposed.

Asbestos↗
PubMed1982

Malignant mesothelioma in Turkish immigrants residing in Sweden.

Mesothelioma is a rare neoplasm in the general population, but it is strongly associated with previous asbestos exposure. The endemic occurrence of this disease in two villages in central Turkey has raised the question of whether the inhalation of naturally occurring zeolite dust may also be a factor in the development of mesothelioma. During the past few years a large portion of the inhabitants of one of the two villages of concern has immigrated to Sweden. This report presents three cases of malignant pleural mesothelioma and the results of a chest radiographic survey among these immigrants. Mineralogical analysis of lung tissue specimens from two of the cases revealed the presence of both zeolite and asbestos minerals and therefore suggested a synergistic effect involving both types of minerals. The importance of close medical surveillance of this high-risk population is emphasized, as is the possibility that similar cases appear in other countries because of increased migration.

Adult↗
PubMed1980

Asbestos as a cofactor in carcinogenesis among nickel-processing workers.

It has been widely assumed, especially in the absence of other explanations, that lung cancer and nasal sinus cancers observed among nickel smelter workers are the result of the carcinogenicity of nickel. Although there may be such influence, supplementary hypotheses are also possible. The nickeliferous ores from at least one major smelter in New Caledonia (excess numbers of cancers have been found in these smelter workers) are derived from serpentinized host rocks which contain large amounts of chrysotile asbestos. Analysis indicates that nickel ores from this area are heavily contaminated by these fibers. The deposits are mined for their nickel content, but workers may be exposed to the asbestos fibers contained in the deposits. Hygiene measures limited to the avoidance of nickel may be inadequate under such circumstances and should be reevaluated so as to prevent the inhalation of asbestos-containing dusts.

Humans↗
PubMed1980

Environmental asbestos concentrations in the United States.

Measurements were made of chrysotile concentrations in buildings with asbestos-lined return air plenums, in buildings with damaged asbestos surfacing material, in the houses of asbestos workers, and around buildings while asbestos-containing fireproofing material was being sprayed on steelwork. The data obtained demonstrate significant environmental contamination by asbestos: 43/89 air samples exceeded 50 ng/m3, although only 2/89 samples exceeded 1000 ng/m3. These findings should prompt appropriate control or remedial action.

Air↗
PubMed1979

Drywall construction and asbestos exposure.

The rapid development of the drywall construction trade in the United States is described. It is estimated that some 75,000 U.S. construction workers are currently employed in this trade. The use of a variety of spackle and taping compounds is shown to be associated with significant asbestos exposure; air samples taken in the breathing zone by drywall tapers during sanding of taping compounds show fiber concentrations exceeding, by several times, the maximum level permitted by United States Government regulations. These findings are given together with the result of a clinical field survey of drywall construction workers demonstrating that asbestos disease may be an important health hazard in this trade.

Adult↗
PubMed1979

The contamination of Lake Superior with amphibole gangue minerals.

Iron ore called taconite is mined in the Biwabik Iron Formation in the Eastern Mesabi region of the Mesabi Range, in eastern Minnesota. After mining, ore is shipped to Silver Bay, Minnnesota for processing and wet magnetic extraction. Tailings from the process are dumped, as a slurry, into a man-made containment delta constructed in Lake Superior. Submicroscopic amphibole fibers and/or cleavage fragments, a component of the gangue, apparently escape from the delta at Silver Bay, and enter Lake Superior. These particles contaiminate the potable water supplies of municipalities drawing directly from the lake. One of the gangue minerals is the amphibole grunerite, whose asbestiform variety is called amosite. Major emphasis of this study was directed at identification of submicroscopic particle pollutants, based on morphology, structure and chemical composition. Quantitative determination of fibrous amphibole phases, present in a range of water samples, was undertaken. Transmission electron microscopy, selected area electron diffraction, and an electron microprobe technique was used for identification and enumeration and this information was compared with data sets determined from standards. Grunerite fiber and/or acicular cleavage fragments, in some instances indistinguishable from asbestiform grunerite, are present in the tailings, lake water and drinking water of a number of municipalities, a result of contamination of the lake at the Silver Bay milling operation. This amphibole is found in drinking water in concentrations which range from 0.6 to 2.8 X 10(6) fiber/liter. The risk to health, associated with direct ingestion of grunerite fiber is unknown and is extrapolated from the asbestiform grunerite (amosite) data base. The biological activity of other fibrous amphiboles observed, unrelated to any asbestiform silicate variety, is presently unknown and warrants investigation.

Asbestos↗
PubMed1978

Variation of properties of chrysotile asbestos subjected to milling.

Mechanical milling is commonly used to produce short chrysotile asbestos for experimental purposes. Such manipulation also decreases fiber crystallinity, alters Si-O and Mg-O interlayer bonding, induces coordination changes in the brucite layer, diminishes the ability of fiber to reduce specific free radicals and physisorb organic molecules, and decreases hemolytic potency and antagonist sorption capabilities. The degree of alteration is related to the time of milling. Results of biological experimentation with these materials must be interpreted with caution. Interaction mechanisms in the biological setting are suggested for chrysotile fiber.

Animals↗
PubMed1977

Environmental asbestos pollution related to use of quarried serpentine rock.

Crushed serpentinite quarried in Montgomery County, Maryland, has been extensively used for paving roads and other surfaces. The mineral assemblage includes antigorite or lizardite as well as chrysotile and tremolite. Air samples taken in the vicinity of serpentine-paved roads show that chrysotile concentrations are about 10(3) times greater than those typically found in urban ambient air in the United States.

Air Pollutants↗