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Biomedical subjects

H J Woitowitz

Publications and source records attributed to H J Woitowitz.

At least 55 records · Page 3Linked to original sources
PubMed1989

Atmospheric concentrations of polycyclic aromatic hydrocarbons during chimney sweeping.

Air sampled from the breathing zone of chimney sweeps during "dirty work" and soot samples were analysed for polycyclic aromatic hydrocarbons (PAH). A total of 20 PAH were quantified by gas chromatography-mass spectrometry in 115 air samples and 18 soot samples. These included benzo(b)fluoranthene, benzo(a)pyrene (BaP), chrysene, dibenz(a,h)anthracene, and indeno (1,2,3-cd)pyrene, all of which are animal carcinogens. The summed atmospheric concentration of these compounds depended on the type of fuel used and averaged 2.27 micrograms/m3 for oil fuel. If a mixture of oil and solid fuel was used the concentration was 5.06 micrograms/m3; pure solid fuel heating yielded 5.08 micrograms/m3. The air concentrations of BaP were 0.36, 0.83, and 0.82 micrograms/m3 respectively. The soot samples recovered after using the three different fuel types were 10.50, 109.10, and 51.25 mg BaP/kg. The maximum total concentrations of the five carcinogenic PAH were 243.70, 691.06, and 213.94 mg/kg respectively. The time weighted, shift mean concentrations of 0.02 to 0.21 micrograms/m3 benzo(a)pyrene obtained on 11 days form the basis for the industrial medical estimation of risk.

Air Pollutants, Occupational↗
PubMed1989

Measurement of inorganic fibrous particulates in ambient air and indoors with the scanning electron microscope.

In the Federal Republic of Germany, the concentration of inorganic fibrous particles in the ambient air is measured by scanning electron microscopy (SEM) in accordance with draft guideline VDI 3492. Fibres of length greater than or equal to 2.5 microns are counted at a magnification of X2000. The concentrations and fibre dimensions of asbestos fibres and other mineral fibres were determined for 231 ambient air samples, 219 indoor air samples taken during asbestos removal and 21 taken at workplaces. In the ambient air measurements in rural and urban areas, the average concentration of other inorganic fibres was greater than 1000 fibres of length greater than or equal to 5 microns per m3. On the average, only about 100 or fewer asbestos fibres of length greater than or equal to 5 microns per m3 were observed. These 'asbestos fibres' from ambient air had low aspect ratios. They differed substantially from asbestos fibres measured in the ambient air close to sources of asbestos emissions, indoors during asbestos removal or at workplaces. Furthermore, the size distribution of these 'asbestos fibres' was similar to that of 'other inorganic fibres'. We suggest, therefore, that a substantial portion of the 'asbestos fibres' observed by SEM analysis in ambient air samples from rural and urban areas should be classified instead as 'other mineral fibres'.

Air Pollutants↗
PubMed1988

[Baking ingredients as a contributory cause of baker's asthma].

140 bakers with occupation-related asthma symptoms and/or rhinoconjunctivitis were tested for specific IgE antibodies against various enzyme-containing baking components. 5-24% of subjects were sensitive to several carbohydrate-splitting enzymes obtained from mould fungi (amyloglucosidase, hemicellulase and alpha-amylase), as well as/or against soya flour. But allergies against the proteolytic enzymes papain and B. subtilis protease were rare (about 1%). These results indicate that various baking components, especially mould enzymes, play a not insignificant role in the causation of baker's asthma.

Allergens↗
PubMed1987

Evaluation and application of a plasma ashing method for STEM fiber analysis in human lung tissue.

A preparation technique for fiber analysis in human lung tissue has been developed that involves freeze-drying and low-temperature ashing. Analysis is made in the analytical scanning transmission electron microscope at a magnification of 10,000 x. With the use of a special counting method, the sensitivity is approximately 80,000 fibers per gram dry tissue with lengths less than 5 microns and 40,000 fibers per gram dry tissue with lengths greater than or equal to 5 microns. In spite of the leaching and contamination effects described in the literature--even for chrysotile fibrils taken from the lung, elemental spectra do not differ essentially from the asbestos standard. In order to carry out a complete check of the preparation method, a suspension of standard crocidolite fibers in water was gelatinated. No changes in length, diameter or aspect ratio distribution occurred. After preparation, at least 40% of the fibers were recovered. Compared to the wide range of fiber concentrations observed in human lung tissue, these recovery rates appear adequate for fiber analysis in lung dust for medical or legal purposes. To date, 70 lung dust specimens have been analyzed. These are discussed in the paper.

Asbestos↗
PubMed1987

Potential health risks from the use of fibrous mineral absorption granulates.

Attapulgite (palygorskite) and sepiolite are fibrous clay minerals used commercially as components in a wide variety of products including oil and grease adsorbents, carriers for pharmaceuticals, cosmetics, and pesticides. They are also components of drilling muds and animal litter and they are used as paint thickeners. The current annual worldwide production of these minerals exceeds one million tons. Although fibrous in nature, the fibre length may vary greatly depending on the location of the geological deposits. American attapulgite is short (0.1-2.5 micron in length, median of 0.4 micron) but palygorskite from other parts of the world is much longer (30% longer than 5 micron). Several samples of these materials have been submitted to scanning transmission electron microscopy (STEM). This paper reports the results of microscopic evaluations and makes a comparison with the data from experimental carcinogenicity studies and it is concluded that fibre length is a most important carcinogenic property.

Environmental Exposure↗
PubMed1986

[Occupational cancer study of asbestos: possibilities and limits of epidemiologic studies on the causes of death in West Germany].

The study is based on 3990 men and women exposed to asbestos dust for at least three years at their place of work, and prospectively and epidemiologically examined since 1 January, 1977. By 31 December, 1983, 336 had been registered as having died. Calculation of standard mortality rates indicates that the incidence of malignant tumour as cause of death was much higher than in the general population of the FRG, that of fatal mesothelioma about 100 times as high. Standard mortality rate for lung cancer was increased by 48% and 175%, respectively, depending on whether exposure to asbestos dust had ended after (subgroup I) or before (subgroup II) 1 January, 1972. Proportional mortality rate of 43% of tumours at all locations, with about 14% lung cancer and about 9% fatal mesothelioma cases in subgroup II, approaches the internationally recognized frequency of asbestos-associated tumours.

Adult↗
PubMed1986

Asbestos dust exposure during brake repair.

About 10,000 tons of chrysotile per year are used in the Federal Republic of Germany for the production of friction materials. During brake repair an unknown number of approximately 300,000 mechanics in automobile service stations are exposed to asbestos dust. In a field study, asbestos fiber concentrations during brake repair were measured. Occupational histories and chest X-rays of brake service mechanics are being examined. Ninety dust measurements in 76 service stations were made by phase contrast microscopy and by scanning transmission electron microscopy. By electron microscopy, extremely fine chrysotile fibers with lengths less than 5 microns were identified in brake drum dust. Fibers with lengths greater than or equal to 5 microns constituted less than 1% of all chrysotile fibers counted in brake drum dust. Short-term asbestos dust exposures were measured by light microscopy in 101 personal samples during blowing out of brakes, and grinding and turning of brake linings. During blowing out of car brakes, as well as during grinding of brake linings, the product of fiber concentration with length greater than 5 microns and sampling time amounted to about 4-5 fibers/ml X min corresponding to a concentration of 10(6) fibers/m3 over 4-5 min. For trucks and buses higher amounts of 5-10 X 10(6) fibers/m3 X min were observed during these operations. From occupational histories of 210 vehicle mechanics, an average duration of employment of mean +/- s = 21 +/- 10 years and a mean cumulative fiber dose of mean +/- s = (0.54 +/- 1.1) X 10(6) fibers/m3 X years were calculated.

Air Pollutants, Occupational↗
PubMed1986

Mortality rates in the Federal Republic of Germany following previous occupational exposure to asbestos dust.

In 1972, a procedure was introduced by the Industrial Injuries Insurance Institutes (Berufsgenossenschaften) of the Federal Republic of Germany, which is to be used by the special occupational health service for employees exposed to asbestos dust. Since 1 January 1972, occupational health examinations are performed when exposure to asbestos dust has been of at least 3 years' duration. On 1 January 1977, a prospective cohort study was started with employees formerly exposed to asbestos dust whilst working for companies manufacturing or using asbestos. Data on these persons are collected in the Central Register of Employees Exposed to Asbestos Dust of the Industrial Injuries Insurance Institutes. A total of 3,070 male and female employees in whom asbestos exposure terminated after 1 January 1972 formed subcohort I of the study. For comparison, 665 persons whose exposure terminated before 1 January 1972 served as subcohort II. In addition to several other inclusion criteria, each individual's permission was required before personal data could be evaluated. Of the subjects in the two subcohorts, 185 and 71, respectively, had died by 31 December 1982. Tumours were more frequently than this cause of death is expected in the general population. In addition to a high incidence of mesothelioma, the standard mortality rate was especially increased for lung cancer. The proportional mortality rates of about 40% for tumours of all sites (with about 17% lung cancer and 8% mesothelioma) especially in subcohort II, seemed to be comparable to the international figures for epidemiological mortality.

Asbestos↗
PubMed1986

Gaseous and adsorbed PAH in an iron foundry.

The increased risk of lung cancer among foundry workers is assumed to be associated with the inhalation of gaseous and particle bound polycyclic aromatic hydrocarbons (PAH). These compounds are produced during pyrolysis of carbon containing loading material in the moulding sand. The concentrations of 20 PAH, some of which are carcinogenic, have been determined in the dusty casting area of an iron foundry by means of gas chromatography and mass spectrometry. The total dust was fractionated by means of a precision cascade impactor. It was possible to differentiate the PAH load in microgram/mg dust in seven particle size fractions ranging from 0.36- greater than or equal to 24.95 microns. Initially, there was an increase of the adsorbed PAH mass concentration with increasing particle diameter up to a maximum of 1.1 microgram/mg in the dust of the 1.57 micron fraction. Thereafter there was a continuous decrease of PAH mass concentration with increasing particle size. When the differing weights of the seven fractions are taken into account, however, the total PAH load of the individual fractions increases steadily with increasing particle size. The inhalable fine dust, 31.4% of the total dust, contains 49.9% of the total adsorbed PAH. The gas phase contained on average three times more carcinogenic PAH with four and five rings than was adsorbed on the dust. Thus the percentage of the gaseous substances amounts to 77% of the total PAH load at the place of work in an iron foundry.

Adsorption↗
PubMed1984

[Mesothelioma as an index tumor of the occupational hazard of asbestos dust].

Mesothelioma arises from the cover epithelia of the serous body cavities and is a most malignant and fatal tumour. Since 1978 42 cases of diffusely growing mesothelioma have been observed. An extreme difference in the expected frequency of mesothelioma among previously severely asbestos-dust-exposed persons and the rest of the population is characteristic. Accordingly, death from mesothelioma does not only show a predominantly high occupational asbestos-dust-risk association but also to environmental exposition by neighborhood and household contact. Thus in production and use of asbestos-containing products a risk must be expected. Due to the great likelihood of asbestos-induced mesothelioma in the individual case it is justified to consider this tumour as signal for asbestos exposition decades ago. In the German Federal Republic "pleural and peritoneal mesothelioma caused by asbestos" is a notifiable occupational disease since 1977. Each diagnosis of mesothelioma initiates the suspicion and thus the medical duty of notification of an occupational disease. Following the large increase of asbestos consumption in the GFR over the last 30 years an increase of medically confirmed mesotheliomas can be expected.

Adult↗