Health hazards due to the inhalation of amorphous silica.

Occupational exposure to crystalline silica dust is associated with an increased risk for pulmonary diseases such as silicosis, tuberculosis, chronic bronchitis, chronic obstructive pulmonary disease (COPD) and lung cancer. This review summarizes the current knowledge about the health effects of amorphous (non-crystalline) forms of silica. The major problem in the assessment of health effects of amorphous silica is its contamination with crystalline silica. This applies particularly to well-documented pneumoconiosis among diatomaceous earth workers. Intentionally manufactured synthetic amorphous silicas are without contamination of crystalline silica. These synthetic forms may be classified as (1) wet process silica, (2) pyrogenic ("thermal" or "fumed") silica, and (3) chemically or physically modified silica. According to the different physicochemical properties, the major classes of synthetic amorphous silica are used in a variety of products, e.g. as fillers in the rubber industry, in tyre compounds, as free-flow and anti-caking agents in powder materials, and as liquid carriers, particularly in the manufacture of animal feed and agrochemicals; other uses are found in toothpaste additives, paints, silicon rubber, insulation material, liquid systems in coatings, adhesives, printing inks, plastisol car undercoats, and cosmetics. Animal inhalation studies with intentionally manufactured synthetic amorphous silica showed at least partially reversible inflammation, granuloma formation and emphysema, but no progressive fibrosis of the lungs. Epidemiological studies do not support the hypothesis that amorphous silicas have any relevant potential to induce fibrosis in workers with high occupational exposure to these substances, although one study disclosed four cases with silicosis among subjects exposed to apparently non-contaminated amorphous silica. Since the data have been limited, a risk of chronic bronchitis, COPD or emphysema cannot be excluded. There is no study that allows the classification of amorphous silica with regard to its carcinogenicity in humans. Further work is necessary in order to define the effects of amorphous silica on morbidity and mortality of workers with exposure to these substances.

[Is the stapled suture in visceral surgery still justified? A prospective controlled, randomized study of cost effectiveness of manual and stapler suture]. / Ist die Klammernaht in der Visceralchirurgie noch gerechtfertigt? Eine prospektiv kontrollierte, randomisierte Studie zur Kosteneffektivität von Hand- und Klammernaht.

Hospitals are facing increasing economic pressure. It therefore seems necessary to evaluate the efficiency and effectiveness of medical or surgical interventions. In this study 324 anastomoses (167 stapled and 157 hand-sewn) were performed after randomization during 200 elective operations [20.5% gastrectomies, 14% gastric resections (Billroth II), 15% Whipple's procedures, 4% segmental colonic resections, 18% right-sided hemicolectomies, 4% left-sided hemicolectomies, 22% sigmoid- or anterior rectal resections, 2.5% total colectomies with pouch-anal anastomoses] in 200 patients. Postoperative motility (time to full oral diet, time with naso-gastric tube) and hospitalization were comparable in both groups. Anastomotic insufficiency was observed in 2.1% of all patients, five after stapled and two after hand-sewn anastomoses. Hospital mortality was 1.5%. All stapled anastomoses were performed significantly (P < 0.001) faster. However, the cost of material for these anastomoses was significantly (P < 0.001) higher, resulting in significantly higher total costs for reconstruction. The time saving for the reconstruction did not influence the total operative time (except for stapled gastrectomy). Therefore, all operations with stapled reconstruction were more expensive than those with sutured reconstruction. The difference was significant for the gastrectomy (P < 0.01), colonic resection (P < 0.01) and sigmoid and rectal resection (P < 0.001) groups. Stapled and sutured anastomoses are equally effective. Stapled anastomoses are not efficient, however, and should be reserved for individual indications.

Effects on the lung function of exposure to carbon black dusts. Results of a study carried out on 677 members of staff of the DEGUSSA factory in Kalscheuren/Germany.

Spirometry, full-bodyplethysmography, and inhalation challenge tests are the most frequently used methods for lung function testing. In all, 677 examinations were performed among exposed employees at the Degussa carbon black plant in Kalscheuren/Germany using the above mentioned methods, in order to detect whether there is a measurable impact of carbon black fine dust on pulmonary function, or a higher prevalence of obstructive air-way diseases among the study candidates, and whether fine dust exposure is related to the prevalence of bronchial hyperresposiveness. Within the smokers' group carbon black dust exposure reveals a (minimal) impact upon the lung function of the study subjects. However, the impact of fine dust exposure within that group is less significant than the influence of smoking on pulmonary function. Nevertheless, smokers are displaying significant more frequently signs of obstructive airway diseases compared with nonsmokers. In the smokers' group we found 7.3% of study subjects with signs of obstructive airway diseases compared with 3.9% in the group of nonsmokers. No significant impact of fine dust exposure on lung function could be detected within former- and nonsmokers. The overall percentage of 5.1% is not higher than that of subjects with bronchial hyperresponsiveness in other comparable studies.