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Asbestos Identification and Abatement
Published in Benjamin Alter, Environmental Consulting Fundamentals, 2019
There are three known asbestos-related diseases: asbestosis, lung cancer, and mesothelioma. Asbestosis is a scarring (fibrosis) of the lung that impairs the elasticity of the lung tissue and restricts breathing. Asbestosis has a latency period of 10 to 30 years and generally is associated with a long, heavy exposure to airborne asbestos fibers.Lung cancer is a malignant tumor of the bronchi covering. Although there are many causes of lung cancer, there is a clear increase in risk among people who worked with asbestos. There is no threshold or level of exposure below which the risk of lung cancer is not increased. The typical latency period for lung cancer resulting from asbestos exposure is 20 to 30 years.Mesothelioma is a cancer of the mesothelium—the lining of the chest or the lining of the abdominal wall. It is the only known type of cancer directly attributed to asbestos exposure. By the time it is diagnosed, it is almost always fatal. There is no exposure threshold for mesothelioma, and the disease may not manifest itself until up to 40 years after the time of exposure to asbestos.
General Introductory Topics
Published in Vadim Backman, Adam Wax, Hao F. Zhang, A Laboratory Manual in Biophotonics, 2018
Vadim Backman, Adam Wax, Hao F. Zhang
A particular type of epithelial tissue is identified through a combination of these two (or three if surface specialization is present) classifications. Simple squamous epithelium lines the inner surfaces of blood vessels (endothelium) and the surfaces of the peritoneal cavity (mesothelium). Simple cuboidal epithelium is found in many endocrine glands (salivary glands, pancreatic duct, mammary gland duct), the free surfaces of the ovary, and the tubes of the kidney. Simple columnar epithelium lines the luminal surface of the large and small intestines and endocervix (the part of the cervix that is close to the uterus). In the case of the intestinal epithelium, the lining folds into larger (100–500 μm) structures called crypts and villi. Crypts are invaginations into the tissue and are present in both the small and large intestines, while villi are invaginations into the lumen and are present in the small intestine only. The purpose of these structures is to increase the surface area to allow for more efficient absorption and secretion. Stratified squamous epithelia are some of the most omnipresent structures and are good for protection. This type of epithelium lines the surfaces of the skin (epidermis), oral cavity, esophagus, exocervix (the lower part of the cervix), the anus, and the upper respiratory tract. The skin epithelium is keratinized, while most other epithelia are considered nonkeratinized, although this classification is a bit confusing; thin layers of keratin are frequently found in the esophagus despite its conventional classification as a nonkeratinized type. Pseudostratified columnar epithelium lines the luminal surfaces of the large airways of the respiratory tract, in particular bronchi. Because of the cilia present on the apical surface of these cells, the full name of the epithelium is ciliated pseudostratified columnar epithelium. Finally, transitional epithelium forms the lining of the bladder. Its unique structure with larger cells on top allows it to withstand stretching.
Reducing the risk of particulate matter containing asbestos using a high-efficiency, low-differential pressure system
Published in Aerosol Science and Technology, 2018
Sung Ho Hwang, Jaehoon Roh, Chanjung Park, Jongcheol Kim, Byong Hyoek Lee, Wha Me Park
Asbestos are naturally occurring fibrous silicate minerals that include chrysotile (serpentine asbestos), actinolite, crocidolite, amosite, anthophyllite, and tremolite (amphibole asbestos). Asbestos used to be widely used in constructions for their various desirable physical properties, including low thermal conductivity, high electrical resistance, resistance to fire, chemicals, and microorganisms, and high sound absorption. However, asbestos cause severe health problems (Wagner et al. 1960; Hillerdal 1999). Although amosite and crocidolite are the most hazardous types of asbestos, all six types have been shown to be carcinogenic (Berman and Crump 2003). Mesothelioma, a rare form of cancer that develops from mesothelial cells, has been observed in people exposed to asbestos. Moreover, asbestosis, an inflammatory medical condition affecting parenchymal tissues of the lungs, is associated with asbestos inhalation.
Analytical transmission electron microscopy of amosite asbestos from South Africa
Published in Archives of Environmental & Occupational Health, 2020
Amosite asbestos has been shown in both epidemiologic and in experimental animal studies to cause mesothelioma, lung cancer, and asbestosis.3 All of the regulated amphibole asbestos types can cause mesothelioma, which is a cancer of the outer lining of the pleura and peritoneum, or mesothelium. Mesothelioma is a generally a rapidly fatal disease that is for all practical purposes only caused by asbestos. The other regulated asbestos mineral is chrysotile, a serpentine group mineral, which rarely if ever causes mesothelioma, since it tends to degrade in the lung.