Asbestos documenting exposure

Several fillers, ineluding asbestos, nickel, and soot, are carcinogens. The health risk due to asbestos exposure is well documented. Exposure to asbestos increases the risk of lung cancer, mesothelioma, asbestosis, pleural thickening, and gastrointestinal cancer. The first four diseases are caused by inhalation of asbestiform fibers, whereas the last is caused by ingestion. 

XZ/N VI RON MENTAL APPLICATIONS OF CHEMOMETRics are of interest because of the concern about the effects of chemicals on humans. The symposium upon which this book is based served as an important milestone in a process we, the editors, initiated in 1982. As members of the Environmental Protection Agency s Office of Toxic Substances (OTS), we have responsibilities for the acquisition and analysis of human and environmental exposure data in support of the Toxic Substances Control Act. OTS exposure studies invariably are complex and range from evaluating human body burden data (polychlorinated biphenyls in adipose tissue, for example) to documenting airborne asbestos levels in schools. 

In the early stages of the disease, fibrotic lesions can be found in the bronchioles and alveolar ducts of the pulmonary tree. If exposure to asbestos is not documented in the patient s life history, laboratory examination (tissue analysis), to demonstrate of the presence of asbestos fibers and ferruginous bodies is necessary. However, the demonstration of these bodies in the ab-... 

The initial connection between asbestos and mesothelioma was made by Wagner et al. (1960), when all but one patient in a study of mesothelioma-related deaths were found to be miners, workers, members of their families, or others living in the area of South Africa where the amphibole-asbestos crocidolite was mined. A comparable occupational exposure to crocidolite has been documented in Australia, with similar results (Armstrong et al., 1984). Mann and his associates (1966) documented three cases of mesothelioma among fifty-four patients dying of pulmonary asbestosis, and in two of the patients the mesotheliomas were peritoneal rather than pleural. 

McDonald and his associates (1973) in Canada found that only 20 percent of mesothelioma cases had a documented history of significant exposure to asbestos, although Selikoff (1977) reported that 7.2 percent of the asbestos workers (in the United States) had the disease. Newhouse and Berry (1979) contended that mesothelioma was often misdiagnosed and stressed the difficulty of reconstructing reliable data on dust levels, especially when the time elapsed since exposure is more than 20 years. 

Another aspect of OELs is that they tend to decrease gradually over time as they are revised. The half-life1 of OELs displayed in Table 9.2 is an example of that. This has also been shown in other several studies, e.g. Hansson (1998) which includes a review of the Swedish OELs from 1969 to 1992. Greenberg (2004) made a review of the documentation of British asbestos exposure limits from 1898 to 2000 and Markowitz and Rosner (1995) reviewed the TLV for silica from 1935 to 1990. Both these studies show that the OELs are lowered as more information on adverse effects becomes available and the protection of worker s health is given higher priority. This aspect points at the influence of each organisation s time-frame for the update procedures. 

Most attention has focused on occupational exposures to chrysotile and amphibole asbestos as it has been mined, processed, and used commercially or industrially. However, there has been some renewed attention to potential occupational, residential, and environmental exposures to asbestos that occur as an accessory mineral in rocks such as serpentinite (Renner, 2000), and to deposits of other industrial minerals such as vermiculite (e.g., Libby, Montana Lybarger et al., 2001 Dearwent et al., 2000 McDonald et al., 1986 Wright et al., 2002 Van Gosen et al., 2002 Meeker et al., in press Wylie and Verkouteren, 2000). Environmental exposures to erionite have also been well documented as... 

OSHA (2008). Occupation Exposure to Asbestos, Section 1. Regulatory History. U.S. Occupational Safety and Health Administration, Washington, D.C. Accessed at http //www.osha.gov/pls/oshaweb/ owadisp.show document p table=PREAMBLES p id=775. 

The health effects of long term or high levels of exposure to airborne asbestos fibres have been well documented since the early 1900s and were reported by the medical profession on many occasions in the first half of the last century. The majority of illnesses that are occurring at the present time are due to exposure forty to fifty years ago during the peak usage and manufacture of asbestos materials for the construction industry. These illnesses include the following fatal diseases ... 

Asbestos is the name given to a group of naturally occurring silicates, chrysotile, amosite, and crocidolite, and the asbestiform types of tremolite, actinolite, and antho-phylite. Exposure to asbestos is a well-documented cause of pulmonary and pleural fibrosis, iung cancer, and mesothelioma, illnesses that may appear many years after exposure. 

The association between exposure to asbestos dust and the development of lung carcinoma and diffuse mesotheliomata of the pleura and peritoneum has been well documented (Selikoff and Lee 1978). Both crocidolite and amosite were capable of augmenting the oncogenic effect of benzo[a]-pyrene. This putative synergistic effect was evident when fibres and chemicals were added to cultures of murine fibroblast cultures as simple mixtures and when benzo[a]pyrene was adsorbed to the surface of the fibres (Brown et al. 1983). 

Possible physiologic results of respiratory exposure to asbestos are mesothelioma of the pleura or peritoneum, interstitial fibrosis, asbestosis, pneumoconiosis, or respiratory cancer. The possible consequences of asbestos exposure are detailed in the NIOSH Criteria Document or in the OSHA Asbestos Standards 29 CFR 1910.1001 and 29 CFR 1926.1101 and 29 CFR 1915.1001. 

Chest radiographs are limited with respect to sensitivity and specificity in the detection of mild or early asbestosis (Fig. 3.1.4.). Among individuals with asbestosis confirmed by histopathological findings, 15-20% had no radiographic evidence of parenchymal fibrosis (Kipen et al. 1987), similar to the proportion of other interstitial lung diseases that present with normal chest films (Epler et al. 1978). More recent studies have shown that between 5% (Paris et al. 2004) and 30% (Lee et al. 2003) of subjects with documented asbestos exposure and pulmonary... 

At present, American Thoracic Society guidelines do not recommend the regular surveillance of subjects with a history of asbestos exposure for lung cancer or mesothelioma (American Thoracic Society Documents 2004). 

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