Mesotheliomas - Asbestosis Research

"Asbestos is a ubiquitous, naturally occurring fiber that has been linked to the development of malignant and fibrotic diseases of the lung and pleura.

These diseases may be initiated by injury to epithelial cells and mesothelial cells by asbestos fibers through the formation of reactive oxygen intermediates. Elaboration of oxidants are also a consequence of inflammation, a hallmark of exposure to asbestos after inhalation or injection of asbestos fibers into animals.

The type, size, and durability of asbestos fibers may be important in toxicity and pathogenicity of asbestos types. This review discusses the pathways of oxidant generation by asbestos fibers, cell-cell interaction that may initiate and perpetuate inflammation, cytokine release and proliferative responses to asbestos, and cell signaling pathways implicated in these events."

"Despite irrefutable evidence that asbestos causes asbestosis, lung cancer, and mesothelioma, asbestos mining, milling, and manufacturing continue. The authors discuss three scientific debates over the roles of fiber types, viruses, and genetics in the development of mesothelioma.

While these controversies might appear internal to science and unconnected to policies of the global asbestos industry, they argue that scientific debates, whether or not fostered by industry, play a central role in shaping conceptualization of the problem of asbestos-related disease.

In South Africa, India, and elsewhere, these controversies help to make the disease experience of asbestos-exposed workers and people in asbestos-contaminated communities invisible, allowing the asbestos industry to escape accountability for its practices."

"New Zealand is a small country with a big asbestos disease problem. The lack of action on warnings in the 1960s and 1970s has led to epidemics of mesothelioma and asbestosis, which can be clearly documented via the death and cancer registers.

In addition, an uncertain number of lung cancers due to asbestos exposure has occurred. The epidemic started in the 1980s, and will eventually have cost the lives of at least 2000 to 3000 workers.

Prevention against ongoing exposures from asbestos installed in buildings is essential, and another key issue for New Zealand is to ensure that fair workers' compensation is provided to all victims of asbestos diseases."

"Asbestos has been used by man since 4000 before the Christian era (BCE) in many different parts of the world and for a wide range of functions. Blue asbestos (crocidolite) was first discovered in South Africa in 1805 and within a few years was being mined there extensively. Mining reached its peak in 1977 with >380,000 tons being exported and 20,000 miners employed in the industry. South Africa also has large deposits of white asbestos (chrysotile) and brown asbestos (amosite) both of which have been mined extensively.

At the turn of the 20th century, it was noted that those working with asbestos suffered lung disease and in 1960, the link between asbestosis and mesothelioma was established in the Kimberley area of South Africa. Further studies in the 1970s and 1980s showed an alarming incidence of mesothelioma based on pathology reports.

The majority of the reported mesothelioma cases result from exposure to asbestos in its many uses in secondary industry although incidence of the condition among miners is also significant. A high proportion of mesothelioma in patients in South Africa is attributed to environmental origin with a high incidence of women and children affected."

"The case for a total ban on manufacture and use of asbestos products is stated by the history of asbestos use, exposures, and risks in Israel. Manufacture and use of asbestos began in Israel in the 1950s, rising to a peak in the mid-1970s, and dropping gradually thereafter until reaching minimal levels in the 1990s. Following heightened public concern regarding the carcinogenic effects of asbestos products, there were reductions in use, manufacture, and persons exposed.

Since the 1960s, asbestos-related diseases have been diagnosed in hundreds patients nationwide, including asbestos workers and users, as well as individuals living proximally to the manufacturing facilities. Exposures to asbestos in place remain, and patients with asbestos-related disease from environmental exposure are expected to appear for at least another 20-30 years. In the 1980s, an advisory committee appointed by the Ministry of Health of Israel outlined a comprehensive approach towards prevention, control, management, and compensation for health risks from asbestos exposures.

As certain areas are still contaminated with asbestos waste and as environmental exposure persists, continued and improved medical monitoring and compensation programs are urgently needed in order to reduce the suffering of exposed individuals and their families. The ban on asbestos prevents risks from new exposures, but does not undo the damage from past manufacture, use, disposal, and dumping. In this paper, we review the history of Israel's import and use of asbestos, and the management of occupational and environmental exposures. We also address policy, practice, and the need to protect future victims of asbestos-related disease."

"In 1950s and 60s, asbestosis had been a major health hazard for asbestos exposed workers. In the late 1970s, lung cancers with or without asbestosis were found among asbestos workers. All cohort studies on asbestos workers and on chrysotile miners in China showed excess deaths from lung cancer.

In a large scale of cohort study on asbestos workers, a synergistic effect was found between cigarette smoking and asbestos exposure in the production of lung cancer. There have been not so many cases of malignant mesotheliomas reported, so far. In the cohort of chrysotile miners, 4 cases of pleural mesothelioma were observed.

In the large scale of cohort study on asbestos workers in 9 factories using only chrysotile only one case of pleural mesothelioma was detected for 10 years' observation. In another 2 cohort studies, 2 cases of peritoneal mesotheliomas were found, one in Shanghai asbestos factory where a small amount of crocidolite had been used in 1960s, and one in Anqing asbestos factory that was located near tremolite mine. Further study is needed especially for the relationship between exposure to Chinese chrysotile and malignant mesotheliomas."

"Chrysotile, or "white", asbestos is the dominant form of asbestos in international commerce today. It accounts for 99% of current world asbestos production of 2 million tonnes. Chrysotile is an extremely hazardous material.

Clinical and epidemiologic studies have established incontrovertibly that chrysotile causes cancer of the lung, malignant mesothelioma of the pleura and peritoneum, cancer of the larynx and certain gastrointestinal cancers. Chrysotile also causes asbestosis, a progressive fibrous disease of the lungs. Risk of these diseases increases with cumulative lifetime exposure to chrysotile and rises also with increasing time interval (latency) since first exposure. Comparative analyses have established that chrysotile is 2 to 4 times less potent than crocidolite asbestos in its ability to cause malignant mesothelioma, but of equal potency of causation of lung cancer. The International Agency for Research on Cancer of the World Health Organization has declared chrysotile asbestos a proven human carcinogen.

Sales of chrysotile asbestos have virtually ended in Western Europe and North America, because of widespread recognition of its health hazards. However, asbestos sales remain strong in Japan, across Asia and in developing nations worldwide. The claim has been made that chrysotile asbestos can be used "safely" under "certain conditions" in those nations. That claim is not accurate. The Collegium Ramazzini, an international learned society in environmental and occupational medicine, has called for an immediate worldwide ban on all sales and uses of all forms of asbestos, including chrysotile. The rationale for this ban is threefold: (1) that safer substitute materials are readily available, (2) that "controlled" use of asbestos is not possible, and (3) that the health risks of asbestos are not acceptable in either the industrialized or the newly industrializing nations."

Mesotheliomas - Asbestosis Research - Asbestos Facts Links

Asbestos - NSC - Read about the description and general uses of this mineral.

EPA's Five Facts Regarding Asbestos - University of Wisconsin-Milwaukee Department of Environmental Health, Safety, and Risk Management offers the Asbestos Management Program.