Hamster peritoneal macrophages were grown in cell culture and their response to various conditions was examined. The cultures responded favorably to high concentrations of serum and to medium which had been preconditioned by contact with tumor cells. After 2-3 days of adaptation, they entered into a period of stability which lasted from the 4th to the 9th day. Macrophage cultures in this stable...

We tried to evaluate the carcinogenic risk of man-made mineral fiber based on the mesothelioma incidence in female F344 rats after intraperitoneal administration. Rats (female F344/ Nslc, 5-week-old, n=330) were observed for 2 years after the intraperitoneal administration of 5 to 20 mg of 9 types of the JFM (Japan Fibrous Material Research Association) standard fiber samples (glass wool, rock ...

About 673 small-scale asbestos mining and milling facilities and 33 large - scale asbestos manufacturing plants, (17 asbestos-cement product manufacturing plants and 16 other than asbestos-cement product plants) are situated in India. The present study reveals the exposure of commercial asbestos (chrysotile) in the occupational as well as ambient air environment of the asbestos-cement (AC) shee...

After intratracheal injection of short chrysotile asbestos fibres in guinea-pigs an intense neutrophil alveolitis was observed within three days. Evaluation by bronchoalveolar lavage of the inflammatory and immune effector cells producing the alveolitis by three days showed an increased proportion of polymorphonuclear leucocytes, which comprised 21% +/- 3% of the total leucocytes compared with ...

A rapid method has been developed for measuring the binding capacity of asbestos and other mineral fibres for environmental carcinogens. Benzo(alpha)pyrene (B(alpha)P), nitrosonornicotine (NNN), and N-acetyl-2-aminofluorene (NAAF) were assayed in the presence of Canadian grade 4T30 chrysotile, chrysotile A, amosite, crocidolite, glass microfibres, glasswool, attapulgite, and titanium dioxide. C...

Asbestos-contaminated vermiculite attic insulation (VAI) produced from a mine near Libby, Montana, may be present in millions of homes along with other commercial asbestos-containing materials (ACM). The primary goal of the research described here was to develop and test procedures that would allow for the safe and effective weatherization of low-income homes with asbestos. The presence of asbe...

This paper gives a critical review of current problems related to quantitative health risk assessment of exposure to asbestos, and particularly to chrysotile, the only type of asbestos still available on the market. The paper reviews types, sources, uses and the main recognized health effects of asbestos, paying particular attention to the health-related properties of fibres and the role of the...

By the use of transmission electron microscopy (TEM) and energy dispersion spectrometry the amount (mean value mean = 191 +/- 94 fibers/mg of tissue) and the type (chrysotile and tremolite) of asbestos fibers have been determined in tissue samples of four bladder cancer patients affected by pulmonary asbestosis, working in the same plant producing asbestos-cement pipes and boards. Similar measu...

Positively charged, synthetic chrysotile nanotubes act as inorganic tectons supporting H- and J-type aggregates of anionic porphyrins with markedly different optical properties, making these nanohybrid materials of interest for application in nanotechnology.